Rodica Blaa MAJOR NEUROLOGICAL SYNDROMES University Press, Trgu Mure 2012 Foreword AlthoughneurologyoftheXXIcenturybenefitsfrom moderndiagnosticmethods,knowledgeandespeciallytimely recognitionofneurologicalsyndromesremainsachallenge andafundamentalprerequisiteofphysiciansandmedical students. Neurologicaldiagnosisinevitablypassesthroughtwo successiveandcomplementaryphases.Inafirstphase,the clinicaldiagnosisofthesyndromesanddiseaseswillbe established.Inthesecondstage,basedonlaboratory examinations,thealreadyestablishedclinicaldiagnosismay beconfirmedorrejected(positiveornegativediagnosis)and therefore differential diagnosis can be made. Clinicalneurologicaldiagnosiscanbeaccurately establishedifatleasttwobasicconditionsaremet:a) existenceofanimportantneurologicalknowledgebase (anatomo-physiology,pathology,pathophysiology,semiology, sindromology); b) use of pragmatic medical thinking and lack of hesitation. Inthemoderneraboththemedical doctorbutespecially theneurologist mustreachthediagnosisasquicklyandas safelyaspossiblebyfollowingacommonlyobstacle-ridden road.Thefirst(analytical)stepofstorage,isbasedonaclear protocol for examination of the signs and symptoms.Thesecondstep(synthetic)comprisesinitsturntwosubsequentphases,a)afirstphaseofestablishingthe syndromediagnosis;b)inthesecondphase,byproperly assemblingsyndromes,diagnosisofthediseaseisreached. Obviously,itisoptimaltimefortheuseoflaboratory examinations, which will be recommended according to clinical data. I Reconsiderationofneurologicalsyndromesfacilitates topographicdiagnosisoflesionswherevertheyarelocatedin the central nervous system and/ or peripheral nervous system. Consequently,neurologymustremainequallyascience andanart,thereforepresentationofmajorneurological syndromesattemptstodemonstratetheurgentnecessityfor them to be acquired both by the Romanian students and by the studentsinvolvedinEnglishprogrammes,atatimewhenthe beautyandnobilityofclinicalneurologymustfinditswell-defined position in the heap of electronic diagnosis devices. Rodica Blaa II CONTENTS I. UPPER MOTOR NEURON SYNDROMES1 II. LOWER MOTOR NEURON SYNDROMES........ 9 III. SOMATOSENSORY SYNDROMES.. 13 IV. AUTONOMIC NERVOUS SYSTEM SYNDROMES....23 V. CRANIAL NERVES SYNDROMES.........33 VI. SPINAL CORD SYNDROMES........55 VII. BRAIN STEM SYNDROMES.65 VIII. VESTIBULAR SYSTEM SYNDROMES.77 IX. CEREBELLAR SYNDROMES......81 X. THALAMIC SYNDROMES..89 XI. EXTRAPYRAMIDAL SYNDROMES95 XII. INVOLUNTARY MOVEMENTS SYNDROMES..117 XIII. CEREBRAL LOBES SYNDROMES.149 XIV. ISCHEMIC CEREBROVASCULAR SYNDROMES...199 XV. MENINGEAL SYNDROME..223 XVI. INTRACRANIAL HYPERTENSION .233 XVII. COMA239 SELECTIVE REFERENCES.......251 III I.UPPER MOTOR NEURON SYNDROMES Uppermotorneuron(corticospinaltract,pyramidaltract) contains about one million nerve cells and fibers and has a phasic functiontocontrolvoluntarymovementsandatonicfunctionto control muscular tonus. The upper motor neurons (corticospinal tract) reside in the precentralgyrusofthefrontallobeandarearrangedina stereotypical fashion (only 60-80% of corticospinal fibers). Neuronswhichcontrolmovementsoffaceandmouthare locatednearthesylvian(lateralfissure)andneurons which control the muscle of the thighs and legs are located near the medial longitudinal fissure and within the central sulcus. Theuppermotorneuronaxonsextendsallthewayfrom the cortex down to the spinal cord. Other sources of corticospinaltract include:Supplementarymotorareaonthemedialsideofthe hemisphere.Premotor cortex on the lateral side.Somatosensory cortex. Superior parietal lobule. Motorhomunculusisabodymap,nearthefissureof Rolando,basedontheamountofcerebralcortexusedto process the different motor outputs of human central nervous system.Thehomunculushasverylargefaceandmouthbecause therearemanyuppermotorneuronswhichinnervate these parts of the body. Duringitsdescentthroughthebrainstem,thecorticospinal tractgivesofffiberswhichactivemotorcranialnuclei, notablythoseservingthemuscleoftheface,jawandtongue (the corticonuclear tract). About 80% of corticospinal fibers cross the midline in the pyramidal decussation. Thesefibersdescendonthecontrolateralsideofthe spinalcordasthelateralcorticospinaltract (crossed pyramidal tract). About10%offibersdonotcrossthemidlineinthe pyramidaldecussationandentertheanterior corticospinaltract(straightpyramidaltract),which occupiestheanteriorfuniculusatcervicalandupper thoracic levels. Thesefiberscrossthewhitecommisureandsupply motor neurons serving deep muscle in the neck. About10%ofthepyramidalfibersenterthelateral corticospinal tract on the same side. Inspinalcord,about55%ofpyramidalfibersstopat cervicallevel,about20%stopatthoraciclevelandabout 25% stop at lombosacrat level. Uppermotorneuronsyndromes(UMNS)orpyramidal syndromes(PS)resultfromlesionsofcorticospinaltract (pyramidaltract)somewherealongitscourseinthecentral nervoussystem(cellbodiesinmotorcortexoraxonsin corona radiata, internal capsule, brain stem and spinal cord). N.B.:Iflesionsoccurabovethelevelofthepyramidal decussating,thesignswillbedetectedontheopposite side of the body.Iflesionsoccursbelowthepyramidaldecussating,the signs will be detectedon the same side. Impairmentofactivemotility(power)=motordeficit (weakness):Paresis/paralysis: Paresis is elective (Wernicke-Mann law). Extensors > Flexors in upper limb. Flexors > Extensors in lower limb. Paresisismoreevidentonupperlimbandatdistal part of the limbs. Paresisforupperlimbispredominantonsupinators, externalrotatorsandabductorsofarmandforearmandextensors of arm. Paresisforlowerlimbispredominantonabductors andexternrotatorsofthigh,flexorsofshankand dorsal flexors of foot. Ifthelesionisunilateral,themotordeficitdoesnot affect axial musculature of the body. Centralfacialparesisbyaffectingthecorticonuclear tract. Paresisofswallowingandspeechwillappearonlyin conditions of bilateral lesions of corticonuclear tract. Grading the strength muscle: 0 = no movement. 1 = only a flicker of movement. 2 = muscle can move only if the resistance of gravity is removed. 3 = muscle strength is reduced and joint can be moved onlyagainstgravitywithresistancecompletely removed. 4 = muscle strength is reduced but muscle contraction can still move joint againstresistance. 5 = muscle contracts normally against full resistance. Terminology: Partial motor deficit (weakness) = paresis. Total motor deficit(weakness) = paralysis/plegia. Monoparesis/monoplegia = paresis/plegia of an upper limb ora lower limb. Hemiparesis/hemiplegia=paresis/plegiaofboth upper and lower limb on the same side. Paraparesis/paraplegia=paresis/plegiaofbothlower limbs. Diparesis/diplegia=paresis/plegiaofbothupper limbs. Tetraparesis/tetraplegia = paresis/plegia of all limbs. Impairmentofpassivemotility(muscletone)=spasticity: Spasticity (muscular contraction)can be present from the onset of lesion: a) if thesewas developed slowlyafter 1-3 weeksfromtheonsetoflesion;b)ifthesewasdeveloped suddenly,whenwasaninitialflaccid(floppy)paralysis (muscularatonia/hypotonia+hyporeflexialossof muscle tone). Spasticity is elective (Wernicke-Mann law). Flexors > Extensors in upper limb. Extensors > Flexors in lower limb. Spasticityfollowingastrokecharacteristicallyaffectsthe antigravity muscles. Spasticity is predominant at distal part of the limbs. Spasticityforupperlimbispredominantonhandflexors, forearmflexors,forearmpronators,armadductorsand arm internal rotators. Spasticityforlowerlimbispredominantonfoot extensors,shankextensors,thighadductorsandthigh internal rotators. Spasticity has an elastic character (continuous giving up). Spasticityhasthetendencytoreturnatinitialposture (claspknife phenomenon). Spasticity has tendency to exaggerate in emotion, cold and orthostatic position. In orthostatic position the patient with spastic hemiplegia hasacharacteristicaspect=theupperlimbwitharmin adduction,forearmandhandinflexion,whilelowerlimb in extension and internal rotation. Clonuscanoftenbeelicitedattheankle/wrist(itconsist ofrhythmiccontractionoftheflexormuscles5-10times/sec in response to sudden passive dorsiflexion). Impairment of automatic motility: Automaticmotilityisdecreasedorabolishedonthe paretic side (e.g.: blinking, balancing of upper limbduring walking). Impairment of pathologic associated reactions : Synkinesesareinvoluntarymovementsofsomeparetic limb segments accompanying physical efforts or voluntary movements of healthy limb segments. Globalsynkineses:involuntarymovementsofparetic limbsaccompanyingphysicalefforts(e.g.:cough, sneeze, open-mouthed). Imitationsynkineses:pareticlimbsegmentsimitate forced movements of healthy limb segments. Coordinationsynkineses:someinvoluntary movementsinpareticlimbsassociatedwithvoluntary movements of the same paretic limbs. Impairmentofdeeptendonreflexes(musclestretch reflexes, myotatic reflexes): Deeptendonreflexesareexaggerated(briskreflexes, hyperreflexia): Hyperreflexia has the following features: The reflexes appear at small mechanical stimulus. Thereflexesappearmorerapidlyaftermechanical stimulus. The reflexes have a great amplitude and vigour. The muscular contraction has a prolonged period. The reflexogen zone has bigger extension. Upper limb reflexes:Biceps reflex (C5/C6). Triceps reflex (C7/C8).Brachiradialis (supinator) reflex (C6). Ulnaris (pronator) reflex (C8/D1). Lower limb reflexes:Patella (knee) reflex (L3/L4).Ankle (Achilles) reflex (S1/S2).Medioplantar reflex (L5-S2). Grading deep tendon reflexes: 0 = no response; always abnormal. 1 = a slight but definitely present response. 2 = a brisk response; normal. 3 = a very brisk response. 4 = a tap elicits a repeating reflex (sustained clonus > 3 beats); always abnormal. Impairment of skin reflexes : Skin reflexes are decreased/abolished: Abdominal skin reflexes: Superior (D7/D8). Middle (D8/D9). Inferior (D10-D12). Other skin reflexes: Cremasteric (L1/L2). Plantar (S1/S2). Pathological pyramidal reflexes and signs: Upper limb = finger flexion reflexes: Manoeuvres of Rosner, Hoffmann, Trmner. Lowerlimb=dorsiflexionofthebigtoe(Babinskisign) signede lvantail. OthersmanoeuvresforBabinskisign:Chaddock,Bing, Oppenheimer, Gordon. Orofacial (bilateral lesions of corticonuclear tracts): Palmomental reflex (Marinescu-Radovici reflex). Buccalreflex(snoutingreflex,orbicularisorisreflex, Toulouse reflex). Triple flexion (Marie-Foix reflex) in tetraplegia/paraplegia (severe bilateral lesions of pyramidal tracts at spinal cord level). Hemiplegic gait: Typical posture during walking: The forearm and fingers are flexed. Thelegonsamesideisinextensionwithplantar flexion of the foot and toes. Whenwaking,thepatientwillholdhisorherarmto one side and drag his or her affected leg in a semicircle (circumduction). Recoveryofmotordeficitofparesisstartswith rhizomelic musculature of lower limb. Topographic diagnosis: UMNS at the cortical level (cortical PS): Hemiparesis is on the opposite side of lesion. Hemiparesis can be limited only at face and upper limb or only at lower limb. Hemiparesisisfrequentlyassociatedwithother corticalsigns(aphasiainthedominanthemisphere, apraxia,agnosia,jacksonianepilepticseizures, hemianopsia etc). Etiology:a)cerebrovasculardiseases;b)cerebral tumor;c) cerebral trauma; d) encephalitis. UMNS atthe internal capsule level (capsular PS): Hemiplegiaisontheoppositesideofposteriorlimb lesion. Hemiplegia is equal in both upper and lower limbs. Spasticity is more precocious and more severe than in cortical pyramidal syndrome. Facialparalysisispresentonthesamesidewith hemiplegia(lesion of bothposterior limb and genu of internal capsule. Recoveryofmotordeficitismoredifficultandmore slowly than in cortical pyramidal syndrome. Etiology:a)cerebrovasculardiseases;b)cerebral tumor. UMNS atthe brain stem level = alternate syndromes: Hemiparesis/hemiplegia is contralateral of the lesion. Paresis/paralysisofoneormoremotorcranial nerves (e.g.: III, VII) are ipsilateral of the lesion. Can be frequently associated with other brain stem signs (e.g.: vestibular, cerebellar). Etiology:a)cerebrovasculardiseases;b)cerebral tumor; c) multiple sclerosis. UMNS at the spinal cord level: Spinalhemiplegia=halfspinallesionabovecervical enlargement. Motor deficit is ipsilateral to lesion. Spinal tetraplegia (quadriplegia): Completespinallesionabovecervicalenlargement= bilateral motor deficit. Spinalcruralmonoplegia=halfspinallesionbelow cervicalenlargement(motordeficitaffectinglower limb is ipsilateral to lesion).Spinalparaplegia=completespinallesionbelow cervicalenlargement(motordeficitisonbothlower limbs). Etiology:a)spinalcordtrauma;b)spinalcordtumor;c) multiple sclerosis.

II. LOWER MOTOR NEURON SYNDROMES Lowermotorneuronisanefferentneuronwhichhasitsbody locatedintheanteriorgraycolumnofspinalcordorinbrain stemnucleianditsaxonpassingbywayofperipheralnervesor cranial nerves to skeletal muscles (final common pathway).Lowermotorneuronsaretheneuronsbringingthenerve impulses from the upper motor neurons out to the muscle. Glutamatereleasedfromuppermotorneuronstriggers depolarization in the lower motor neurons in the anterior hornofspinalcordwhichinturncausesanaction potentialtopropagatethelengthoftheaxontothe neuromuscular junction where acetylcholine is released to carry the signal across the synaptic cleft to the contact. Lowermotorneuronsareclassifiedbasedonthetypeof muscle fiber they innervate:Alfamotorneuronsinnervateextrafusalmusclefibers,the most numerous type of muscle fiber and the one involved in muscle contraction. Gammamotorneuronsinnervateintrafusalmusclefibers, whichtogetherwithsensoryafferentscomposemuscle spindles(partofsystemforsensingbodyposition= proprioception). Lowermotorneuronsyndromes(LMNS)resultfromlesionsof lowermotorneuronsomewherealongitscourse(cellbodiesin brainstemandanteriorhornofspinalcord,axonsinbrainstem, cranial nerves, spinal roots and peripheral nerves). Impairment of active motility = motor deficit (weakness): Paresis/paralysis: Paralysisincludeallvoluntaryandreflexmovements dependent on affected motor neuron. Motor deficit of the musclesis proportional to number of affected motor units. Motordeficitcanbelimited(e.g.:mononeuropaty)or extended (e.g.:polyneuropaty, polyradiculoneuropaty). Mononeuropaties: Axillary (C5/C6) arm abduction. Musculocutaneous (C5/C6) elbow flexion. Radial (C6-C8) elbow extension. Ulnar (C8/T1) finger abduction/ adduction. Femoral (L2-L4) hip flexion + knee extension. Obturator (L2-L4) hip adduction. Superior gluteal (L4-S1) hip abduction. Sciatic (L5-S2) knee flexion. Deep peroneal (L4/L5) ankle dorsal flexion. Anterior tibial (S1/S2) ankle plantar flexion. Posterior tibial (L4/L5) foot inversion. Superficial peroneal (L5/S1) foot eversion. Impairment of passivemotility (muscle tone): Hypotonia: Hypotonia is on the same muscle with weakness. Diminution/disappearance of muscle aspects. Reduction of muscle tone. Exaggerationofpassivemovementsoftheaffected limbs. Impairment of automatic mobility: Automatic mobility (e.g.: blinking, balancing of upper limb during walking): Decreased or abolished on paretic muscles. Impairment of muscular trophicity: Muscular atrophy (muscular wasting): Appearsaftersomeweeksfromlowermotorneuron lesion. Appearsmorerapidlyaftercuttingthancompression of lower motor neuron. In progressivelesion, muscular atrophy appearbefore motor deficit. Impairment of deep tendon reflexes:Deep tendon reflexes are diminished or abolished: Diminished/abolishedofdeeptendonreflexesis presentonlyontheterritoryofaffectedlowermotor neuron. Intensitydiminutionofdeeptendonreflexesis dependent on number of affected motor units. Ifthelowermotorneuronlesionprogress,the diminisheddeep tendon reflexes become abolished. Involuntary movements: Fasciculations:Fasciculations,whicharevisibletwitchingsofsmall groups of muscle fibers in the early stage of wasting. Fasciculationsappearonlyafterslowlyiritativelesionsof lower motor neuron at the level of nerve cell body. Theyarisefromspontaneousdischargeofmotor neurons with activation of motor units. Fibrillations: Fibrillations, which are minute contractions detectable only by needle electromyography. They are the result of denervationsupersensitivity. Impairment of muscles contraction and structure: Muscularcontractionisinnormallimitsuntilmuscle atrophy do not reach an important degree. Needle EMG abnormalities: Poor EMG recording. Fibrillation potentials. Fasciculation potentials. Denervation potentials. Muscle biopsy: Denervationmuscleatrophyiscorrespondingto lesion of motor units. Reduction in the size of muscle fibers (group atrophy). Enlargement of intact motor units. Degenerative changes in some muscle fibers. Topographic diagnosis: LMNS atthe anterior horn level: Paralyses have a radicular distribution. In acquired diseases, the paralyses are asymmetrical. In hereditary diseases, the paralysesare symme-trical. Fasciculations are presentin slowly iritative lesions of nerve cell bodies. Etiology:a)chronicpoliomyelitis;b)progressive spinal muscular atrophy. LMNS at the anterior spinal roots level: Paralyses have a radiculardistribution (radiculitis) Fasciculations are notpresent. Frequent associated with signs of posterior roots lesions. Etiology:a)Pottdisease;b)spinaltrauma;c)spinal tumors;d)spinaldischerniation;e)polyradiculo-neuropaty(e.g.: Guillain-Barr syndrome). LMNS at the plexuses level: Paralyseshaveanintermediatedistributionbetween radiculitis and neuritis. Constantassociatedwithsensitiveandautonomic signs. Etiology: a) polyradiculoneuropaty. LMNS at peripheral nerves: Paralyses have a neuritis distribution. Polyneuritisdistribution:a)symmetrical;b)predo-minant distal; c) predominant at lower limbs level. Constantassociatedwithsensitiveandautonomic signs. Onlymotorsignsifnerveshasonlymotorfibers(e.g.: hypoglossal, accessory) or if the pathogen agents have a motor tropism (e.g.: lead).Etiology:a)mononeuritis(e.g.:traumatic);b)mono-neuritismultiplex(e.g.:immunological);c) polyneuritis(e.g.:diabetesmellitus,toxic, immunological, hereditary, vitamin deficiency). III. SOMATOSENSORY SYNDROMES Somatosensorysystemincludethenervousstructuresthat ensuretotalsomatosensoryfunctionsandisorganizedonthree levels: a) receptor level (sensory receptors);b) transmitter level (sensory tracts), c) perception level (sensory cortex). Receptorlevelincludespecializedendingsofafferent neuronsorseparatecellsthataffectendsofafferentneurons fortouch,temperature,nociception(pain)and proprioception (body position).Sensoryreceptorscovertheskinandepithelia,skeletal muscle,bonesandjoints,internalorgans,including cardiovascular system.Thesensorysystemreactstodiversestimuliusing different receptors (e.g.: tactile-, thermo-, noci-, mechano-, chemoreceptors).Thereceptorscollectinformationaboutexternaland internalenvironmentinvariousenergyforms (stimulus).Stimulus energy is transformed into an electrical response (stimulus transduction).Eachreceptorisspecifictoacertaintypeofstimulus, which is called its adequate stimulus.Specificityalsoexistsintherangeofstimulusenergies that the receptor responds.A receptor can be activated by a nonspecific stimulus if its intensity is sufficiently high. Transmitter level has two separate levels, first in peripheral nervous system and second in central nervous system.Inperipheralnervoussystemasingleafferentneuron with all its receptor endings makes a sensory unit.The first neuron always has its cell body in the dorsal root ganglion of spinal nerve (if sensation is in head or neck, it willbethetrigeminalnerveganglionorthegangliaof other sensory cranial nerves).Incentralnervoussystemafferentaxonsdivergeand synapseuponmanyinterneuronandendsinthesecond neurons. The neurons ascending axons will cross (decussate) to the opposite side either in the spinal cord or in the brain stem.Theseafferentneuronsarecalledsensory(ascending) pathwaysand have three components, regarding the type of stimulus:Spinothalamic pathways (anterior and lateral tracts) exteroceptivesensation=pain,temperature,non-discriminative touch. Dorsalcolumnpathwayinthespinalcordandmedial lemniscusinbrainstemconsciousproprioception= jointposition,vibration,deeppressure,discriminative touch; Spinocerebellarpathways(anteriorandposterior tracts) unconscious proprioception.Theaxonsofmanyoftheseneuronsterminateinventral posteriornucleusofthalamuswhereisthethirdneuron, which ends in the postcentral gyrus of parietal lobe. Perceptionlevel(primarysomatosensoryarea)inhuman cortex is located in the postcentral gyrus.Areasofthispartofhumanbrainmaptocertainareasof thebody,dependonamountorimportanceof somatosensoryinputfromthatarea(e.g.:thereisalarge area of cortex devotedto sensation in the face and hands, whilethebackhasamuchsmallerarea(sensory homunculus). Somatosensorysystemsyndromesresultfromlesionsof sensorysystemsomewherealongofsensorypathwayscourses (peripheralnerves,cranialnerves,spinalroots,spinalcord, brainstem, thalamus, thalamocortical tracts, cortex). Positive sensory disorders: Pain=anunpleasantsubjectivesensoryandemotional experience associated with or described in terms of actual or potential tissue damage. Acute pain =can be brief, lasting moments or hours, or it can be persistent, lasting less than 30 days, until the disease or injury heals. Subacutepain=persistentpain(continuousor recurrent) that lasts from one to six months.Chronicpain=persistentpain(continuousor recurrent) of more than six months. Nociceptivepain=paincausedbystimulationof peripheralnervefibersthatrespondonlytostimuli approachingorexceedingharmfulintensity(e.g.: thermal,mechanical,chemical,visceral,deepsomatic, superficial somatic). Somaticpain=nociceptivepaininmusculoskeletal system (the localization of pain is precise). Visceralpain=nociceptivepaininaninternalorgan (thelocalizationofpainisdiffuse,generallyonthe anatomic territory of the affected internal organ).Referredpain=visceralpainisoftenfeltinplaces remotefromthelocationoftheaffectedorgan(e.g.: referredcardiacpain).Thereferredpainisknownas viscero-somatic convergence. Neuropathicpain=paincausedbydamageordisease affectinganypartofthenervoussysteminvolvedin bodily feelings (the somatosensory system). Neuralgia=peripheralneuropathicpainfeltinthe distributionofanerveroot,dueusuallytoaproximal lesion of that nerve and is often described as burning, tingling,electrical,stabbingorpinsand needles.Thecharacteristicsofsuchpainstendtobe constancyintheirintermittency,brevity,severityand explosive onset in the territory supplied by the nerve. Primaryneuralgia(unknownorigin)=painappearin criseswithoutpainbetweencrisesandwithout hypoesthesia on affected nerve territory. Secondaryneuralgia(knownorigin)=painappearin criseswithobscurepainbetweencrisesandwith hypoesthesia onaffected nerve territory. Radiculalgia=neuralgiacausedbyirritationtothe sensory root of a spinal nerve and is radiated along the radicular dermatome. Phantompain=painfromapartofthebodythathas beenlostorfromwhichthebrainnolongerreceives signals (phantom limb pain is a common experience of amputees). Psychogenicpain(psychalgia,somatoformpain)= paincaused,increasedorprolongedbymental, emotional or behavioural factors. Causalgiaisasympathalgia=spontaneousburning sensation(shootingpain)inthedistributionofthe injurednervewithincreasedsensitivitytopainful stimuli. Causalgiaisapainthatdevelopsafterarelatively minorinjurytoanarmorleg,afteraninitiating noxiouseventoracauseofimmobilization,butlasts muchlongerandismuchmoreseverethanwould normallybeexpectedandthepainiscontinuousand may be heightened by emotional or physical stress.The symptoms vary in severity and duration.Hyperalgesia=whenthresholdtopainappears lowered. Hyperpathia=painthresholdelevated,butonce reached, the painful stimulus is excessively felt. Hyperesthesia = an abnormal increase in sensitivity to stimuli. Paresthesia = a sensation of tingling, burning, pricking or numbness (pins and needles). Dysesthesia = an unpleasant, abnormal sense of touch. Allodinia=apainduetoastimuluswhichdoesnot normally provoke pain. Negative sensory disorders: Decreased/abolished sensation: Hypoesthesia=partiallossofsensitivitytosensory stimuli. Anesthesia = total loss of sensitivity to sensory stimuli.Posterior horn syndrome: Pure sensory disorders: Ipsilateralsegmentalsensoryloss,especiallyofpain and temperature. Preservation of pain and temperature sensation below the level of damage. Spontaneousattacksofpainmaydevelopinthe analgesic area. Posterior root and spinal ganglion syndromes: Pure sensory disturbances: Lancinating pain. Abolitionofallsensorymodalitiesinthecorres-ponding dermatomes. Hypotonia in the corresponding muscles. Hypo/areflexiaofthestretchreflexesinthe corresponding affected roots. Etiology: a) spinal trauma; b) herpes zoster infection. Anterior and posterior roots syndromes: Mixed (sensory and motor) disturbances: Abolition of all sensory modalities. Flaccidparalysisincorrespondingdermatomesand myotomes. Areflexia. Occasionally pain. Etiology:a)Guillain-Barrsyndrome(acute inflammatory demyelinating polyradiculoneuropathy). Guillain-Barr syndrome (GBS): Themajorclinicalmanifestationisweakness,which evolvesmoreorlesssymmetricallyoveraperiodof several days or a week or two. Proximalaswellasdistalmusclesofthelimbsare involved,usuallythelowerextremitiesbeforetheupper (Landrys ascending paralysis). At an early stage, the arm muscles may be less weak than the leg muscles or are spared entirely. Thetrunk,intercostal,neckandcranialmusclesmaybe affected letter. Frequently,thelowercranialnervesmaybeaffected, leadingtofacialdiplegia,bulbarweaknessandoro-pharyngeal dysphagia Theweaknesscanprogresstototalmotorparalysiswith death from respiratory failure within a few days. More than half of the patients complain of pain and aching discomfort in the muscles, mainly in hips, thighs and back. Objectivesensorylossoccurstoavariabledegreeduring thefirstdaysandinafewisbarelydetectablewhensuch loss is present, deep sensibility (touch-pressure-vibration) tendstobemoreaffectedthansuperficialsensibility (pain-temperature. In fact, pain is a common symptom and usually is mild. Reducedandthenabsenttendonreflexesareconsistent findings. InseverecasesofGBS,lossofautonomicfunctionis common,manifestingaswidefluctuationsofblood pressure,orthostatichypotension,cardiacarrhythmias, lossofsweatingorepisodicprofusediaphoresisand urinary retention. InCSFitisanalbumin-cytologicaldissociationwith elevatedproteinlevel(reachingapeakin4to6weeks), without increased cell count (few lymphocytes). GBSisduetoanimmuneresponsetoforeignantigens through a phenomenon called molecular mimicry. Thoracic outlet syndrome (TOS): TOSisacompressionofthesubclavianarteryandthe brachialplexusnervesatthesuperiorapertureofthe thorax. TOS includes several separate syndromes such as: Scalenus atticus syndrome. Cervical rib syndrome. Costoclavicular syndrome. Clinically:Pain ( sharp, burning or aching) in the arms and hands. Pain can involve only part of the hand, as in 4th and 5th finger only or all of the hand. Paincaninvolvetheinneraspectoftheforearmand upper arm. Paincanalsobeinthesideoftheneck,thepectoral areabelowtheclavicle,theaxillaryareaandupper back, as in the trapezius and rhomboid area. One hand colder than the other hand is common. Edemaofthearmandvenousdistensionisrelatively rare. Raynaudsphenomenon,decoloration,coldand trophic changes are occasionally significant. Etiology:Thecompressionmaybepositionalcausedby movement of the clavicle and shoulder girdle. Thecompressionmaybestaticcausedby abnormalities,enlargementorspasmofvarious musclessurroundingthearteries,veinsandbrachial plexus, including a first rib fixation and a cervical rib. Peripheral nerves syndromes: Mixed (sensory and motor) disturbances: Pains. Hypoesthesia/anesthesiaintheterritoriesofaffected nerves,generallypredominantfortemperatureand touch. In some polyneuropaties (e.g.: diabetes mellitus) there is an elective alteration of proprioceptive sensory. Inpolyneuropaties,thedisturbanceofsensoryare bilaterally,symmetricallyandwithdistal accentuation. Etiology:a)trauma;b)compression;c)toxic, infectious,vitaminsdeficiency,metabolicorimmunity factors.Carpal tunnel syndrome (CTS): CTS is an entrapment median neuropathy. Clinically: Intermittentnumbnessandtingling(pinsand needles)and/orpaininthehandthumb,indexlong andradialhalfofringfinger(innervatedbythe median nerve). The numbness often occurs at night. Weakness of the thumb, hypotonia and atrophyof the tenarmusclesmayoccuriftheconditionremains untreated. Raynauds phenomenon and acrocyanosis are rare. Etiology: CTSrepresentsacompressionneuropathyofthemedian nerve (intrinsic factors that exert pressure within tunnel repetitive use of the hand wrists and extrinsic factors that exert pressure outside the tunnel benign tumorsand/or vascular malformation) Complex regional pain syndrome (CRPS): CRPStypeI(reflexsympatheticdystrophy,Sudeck atrophy,reflexneurovasculardystrophy,algoneuro-dystrophy) does not have demonstrable nerve lesions and is characterized by: Presence of continuous pain, allodynia or hyperalgesia. Muscle spasms.Local swelling. Abnormally increased sweating.Changesinskintemperature(usuallyhotbut sometimescold)andcolour(brightredorareddish violet).Softening and thinning of bones.Jointtendernessorstiffnessand/orrestrictedor painful movement.Moving or touching the limb is often intolerable.CRPStypeII(formerlyknowncausalgia)hasevidenceof obvious nerve damage. Posterior spinalcord column syndrome: Lancinating pains in the legs. Areflexia of the patellar and ankle stretch reflexes. Tabetic dissociation:Lossofconsciousproprioceptionanddiscriminative touch; Perseverenceofpain,temperatureandnon-discriminative touch. Sensorygaitataxia(worseindarknessorwitheyes closed). Rombergs sign. Etiology: Tabes dorsalis. Central spinal cord syndrome: Syringomyelic dissociation: Bilateralvest-like(suspended)lossofpain, temperature and non-discriminative touch. Perseverenceofconsciousproprioceptionand discriminative touch. Etiology: a) syringomyelia; b) hematomyelia. Brain stem sensory syndromes = alternate syndrome: Lesionoftrigeminalnucleusinduceslossoftotalsensoryof ipsilateral face. Lesionsofspinothalamictractandmediallemniscus induce loss of total sensory of contralateral body. Etiology:Cerebrovascular diseases. Thalamic syndrome: Subjective disorders: Contralateral pain, but face is exceptional affected. Numbness,burningandtinglingsensationsis severe,persistent,paroxysmalandoften intolerable. Burningandtinglingisaccompaniedbyhyper-sensitivity. Less commonly, some patients develop severe ongoing pain with little or no stimuli. Objective disorders: Contralateralhypoesthesiamoreaccentuatefor proprioception. Etiology:Cerebrovascular diseases. Cortical sensory syndromes: Objective disturbances: Contralateralhypoesthesiamoreaccentuatefor proprio-ception.Touch sensory is moderate affected. Temperature sensory often remain intact. Etiology:a)cerebrovasculardiseases;b)cerebral tumor; c) craniocerebral trauma. IV. AUTONOMIC NERVOUS SYSTEM SYNDROMES. Autonomicnervoussystem(ANS)regulatesthefunctionsof heartmuscle,smoothmuscles,secretoryglandsandhormone secretion. ANSconsistsoftwodifferentfunctionalandanatomical divisions,thesympathetic(SNS)andparasympathetic(PNS) nervous system.TheSNSandPNSregulatevisceralfunctionsasan interactive, dynamic network to meet the requirements of theouterandinnerenvironmentandtomaintainthe homeostasis of the body.A 2-neuron chain characterizes the structure of ANS.Thecellbodyofprimary(presynapticorpreganglionic) neuron,locatedwithintheCNS,sendsitsaxonoutto synapsewiththesecondary(postsynapticor postganglionic)neuronlocatedinoneoftheoutlying autonomic ganglia, whence the postganglionic axon passes to its terminal.Sincethepostganglionicoutnumberthepreganglionic neuronsbyratioof~32:1,asingleprimaryneuronmay servetodischargeanumberofganglioncellsthus,ANS functionsofaratherextensiveterminalareamaybe controlled by relatively few central connections. Functionally,ANSisdividedintosensory(afferent)and motor (efferent) subsystems.Withinthesesubsystems,thereareinhibitoryand excitatory synapses between neurons.SNSandPNStypicallyfunctioninoppositiontoeach other. But this opposition is better termed complementary in nature rather than antagonistic.Attheeffectororgans,sympatheticganglionicneurons release noradrenaline.Thepreganglionicneurotransmitterforbothdivisionsof ANS is acetylcholine.Inthesametime,acetylcholineisapostganglionic neurotransmitter of parasympathetic neurons. SNS has, as generalaction, mobilization of the bodys nervous system(fight-or-flightresponse)whichcorrespondswith arousal and energy generation and inhibits digestion.It is, however, constantly active at a basal level to maintain homeostasis.Theshorterpreganglionicneuronsoriginatefrom thoracolumbarregion(intermediolateralecellcolumn)of the spinal cord (T1-L2, specifically).Theaxonsofthesecells(preganglionicfibers)aremostly myelinated fibers.Aftertraversingtheventralroots,theyformthewhite communicatingramiofthethoracicandlumbarnerves, throughwhichtheyreachthetrunkgangliaofthe sympathetic chain.Branches from the sympathetic trunk may be classified as follows: Thosecomposedofpostsynapticfibers(mainly unmyelinated)graycommunicatingramijoinallof spinal nerves.Throughtheserami,vasomotor,pilomotorandsweat glandinnervationisdistributedthroughoutthe somatic areas. Branchesofthesuperiorcervicalsympatheticganglion enterintotheformationofthesympatheticplexuses abouttheinternalandexternalcarotidarteriesfor distribution of sympathetic to the head. Thesuperiorcardiacnervesfromthe3pairsofcervical sympathetic ganglia pass to the cardiac plexus at the base oftheheartanddistributeacceleratorfiberstothe myocardium. Branchesfromtheupper5thoracicgangliapasstothe thoracicaorta(vasomotor)andtheposteriorpulmonary plexus, through which dilator fibers reach the bronchi. Thosecomposedofpresynapticfibersaremainly myelinated.Thesplanchnicnervesarisingfromthelower7thoracic ganglia pass to the celiac and superior mesenteric ganglia, wheresynapticconnectionsoccurwithganglioncells whoseaxonsthanpasstotheabdominalvisceraviathe celiac plexus. Thelumbarsplanchnicnervesarisingfromtrunkganglia inthelumbarregionconveyfiberstosynapticstationsin theinferiormesentericganglionandsmallganglia associatedwiththehypogastricplexus,throughwhich postsynaptic fibers are distributed to the lower abdominal and pelvic viscera. Function of SNS:Divertsbloodawayfromgastrointestinaltractand skin via vasoconstriction. Bloodflowtoskeletalmusclesandthelungsis enhanced; Dilates bronchioles of the lung. Increasedheartrateandthecontractilityofcardiac cells; Dilatespupilsandrelaxtheciliarymuscletothelens, allowing more light to enter the eye and far vision. Provides vasodilatation for the coronary vessels of the heart;Constricts the intestinal and the urinary sphincters. Inhibits peristalts.PNSpromotesarestanddigestresponsecalmingofthe nerves return to regular function and enhances digestion.PNSarisesfrompreganglioniccellbodiesinthegray matterofthebrainstemandthemiddle3segmentsof sacral cord. The PNS, in contrast to that of SNS, is confined entirely to visceral structures.Mostofpreganglionicneuronsrunwithoutinterruption fromtheircentralorigintothewalltheysupplyorto wheretheysynapsewithterminalganglioncells associated with plexus in the intestinal tract. Nervesconveyingparasympatheticfibers(craniosacral) consist of: Vagusnerve(cranialnerveX),whichdistributesits autonomic fibers to the thoracic and abdominal viscera via prevertebral plexuses. Sacralnerves(S2-S4),whichformspelvicnerveand distributesparasympatheticstomostlargeintestine andpelvicvisceraandgenitaliaviathehypogastric plexus. CranialnervesIII(ciliaryganglion),VII (submandibularandpterigopalatineganglia)andIX (oticganglion),whichdistributepara-sympatheticsto the head. Function of PNS:Dilatesbloodvesselsleadingtothegastro-intestinal tract, increasing blood flow. Constricts the bronchiolar diameter. Controlsthe heart. During accommodation, the PNS causes constriction of thepupilandcontractionoftheciliarymuscletothe lens., allowing for closer vision. Stimulatessalivaryglandsecretionandaccelerates peristaltsandmediatesdigestionoffoodand indirectly, the absorption of nutrients. It is involved in erection of genitals. Stimulates sexual arousal. Peripheral ANS is controlled by the central nervous system (CNS)viacomplexneuronalinterconnectionsfunctioningin relationtoeachothertoformafunctionalentitycalled central autonomic network (CAN). CANhastonic,reflexandadaptativecontroloverautonomic functions.Inaddition,itregulatesendocrine,behavioral motor,pain-controllingresponseandcontributestothe regulation of attention and emotional behaviour.In CAN may be included: Insularcortex-lyingdeepinthetemporallobeis mainlyaviscerosensorycortex(leftinsularcortex seeptobepredominantlyresponsibleforPNSeffects, whereasrightinsularcortexismorelikelytoproduce SNS responses). Prefrontal cortex. Amygdala. Hypothalamus. Midbrain.Medulla oblongata. Spinal cord.Autonomicregionsoftheprefrontalcortexinclude ventromedialprefrontalcortexandtheanteriorcingulate gyrus. Theventromedialprefrontalcortexisinvolvedinthe regulationofhighlevelemotionalandcognitive functionswhereastheanteriorcingulate(infralimbic) cortex constitutean autonomic premotor area. In the amygdala with adjacent areas (extended amygdala) integratesautonomicresponseswithemotionalfactors. Its functions are to interpret the emotional significance of incomingsensoryinformationandtogeneratethe appropriateautonomic,behavioral,motor,endocrineand pain-suppressing responses to environmental stimuli.Theamygdalareceivescardiopulmonaryinformation andhasdirectprojectionstoautonomiccontrolsites, suchashypothalamus,parabrachialregion,nucleus tractussolitarius(NTS)andthedorsalmotornucleus of the vagus which may be the anatomical substrate for descending control over the ANS. Thepreopticregionofthehypothalamusforman anatomicofunctionalunitessentialforintegrationof autonomic,endocrineandbehavioralresponsescritical for homeostasis and reproduction. Inhypothalamus,theperiventricularareacontrols neuroendocrinefunctionsaswellasbiological rhythms. Themedialareahasregulatoryfunctionover homeostasis and reproduction.Thedorsomedialnucleusespeciallycontributestothe integration of cardiovascular responses to stress. The lateral area regulates behavioral functions, as well asvagalfunctionsincludingcardiovascular, gastrointestinal motility, secretion and insulin release.Thezonaincertamergingventromediallywiththe lateralhypothalamicareahasbeenimplicatedin arousal, locomotion and autonomic regulation.Theparaventricularnucleusinnervatesallautonomic centers. Allthemidbrainareasareinconnectionwithautonomic centers in brain stem and spinal cord.Periaquaductalgraymatterinthemidbrainintegrates autonomicresponseswithantinociceptiveand behavioral reactions.Theparabrachialregionintheponsfunctionsasa mediatorinprocessingvisceralandsomatosensory informationanditplaysamajorrolein cardiorespiratoryregulationandstimulationofit producesanincreaseinarterialbloodpressureand inhibition of the baroreflex. Thelateralpartoftheparabrachialregionhas connections to cerebellum.The cerebellar uvula has been implicated in the control of cardiovascular and respiratory function.In medulla oblongata NTS plays a critical role in medullary reflexesandrelayviscerosensoryinformationtoall regions of CAN.There are several areas in the medulla that participate inthecontrolofvasomotortone,cardiacfunctionand respiration (e.g.: the rostral ventrolateral medulla). ANS syndromes (dysautonomia):Dysautonomia (autonomic dysfunction) is a broad term that described any disease or malfunction of the ANS.Dysautonomia include:Horner syndrome. Adie syndrome. Postural orthostatic tachycardia syndrome. Inappropriate sinus tachycardia. Vagovagal syncope. Pure autonomic failure. Neurocardiogenicsyncope. Shy-Drager syndrome. N.B.:AllthediseasesincludedinMultiplesystematrophy(e.g.:Shy-Dragersyndrome,sporadicolivopontocerebellaratrophy, striatonigral degeneration) have different degrees of dysautonomia. Hornersyndrome(HS)=ClaudeBernard-Horner syndrome: HS is an oculosympathetic palsy. Clinically (ipsilateral): Partial ptosis of the upper lid.Miosis. Enophthalmos. Anhidrosis of the face. Flushingoftheface(warmskinoftheforehead, conjunctivalhyperemia,epiphoraandnasal stuffiness). Ocular hypotonia. Increased accommodative amplitude. Etiology: First-orderneurondisorder(centrallesionthat involvethehypothalamospinaltracttransactionof the cervical spinal cord). Second-order neuron disorder (preganglionic lesions compressionofthesympatheticchainbya laterocervical or thoracic tumor). Third-order neuron disorder (postganglionic lesions at theleveloftheinternalcarotidartery(atumorinthe cavernous sinus or a carotid artery dissection).Adie syndrome (AS) = Adie tonic pupil: AS presents three hallmark symptoms (ipsilateral): Unilateraldilatedpupil(mydriasis)whichdoesnot constrict in response to light. Accommodation is normal, slow or tonic. Absent of deep tendon reflexes (generalized or to knee and ankle). Orthostatic hypotension. Generalizedsudorimotorimpairment(excessive sweating orhypohidrosis). The women are more susceptible to this disease. N.B.: mydriasis + loss of tendon reflexes + excessive sweating= Ross syndrome Etiology: Lesions(viralorbacterialinflammation degeneration)ofpostganglioniccellsandfibersofthe parasympatheticsystem(ciliaryganglionand/orthe ciliary nerve fibers). Degeneration of cell bodies in dorsal columns. Shy-Drager syndrome (SDS): SDSisadegenerativedisorderofbrainandspinalcord affectingtheautonomicnervoussystemofmultiple system atrophy. Clinically: SDS affects both sexes with a preference for male. Bloodpressurevariationswithorthostatic hypotension:a)ademonstrabledropinblood pressure on standing of at least 30/20 mm/Hg; b) dizziness; c) severe attacks of syncope. Sphincterdysfunctions:a)urinaryandfecal incontinence;b)nocturnaldieresis;c)urinary retention; d) chronic constipation. Impotence and/or loss of libido. Extrapyramidalsyndrome:a)maskedface;b)pillro-llingtremor;c)cogwheelrigidity(bilateraland symmetrical). Corticobulbar and corticospinal syndrome: a) Babinskisign;b)hyperreflexia; c)dysarthria;d) briskjawjerk;e)forcedlaughingandcrying;f) swallowing difficulties. Cerebellarsyndrome:a)intentiontremor;b)gait ataxia;c) ataxic dysarthria or scanned speech . Secretorydisorders:a)markedimpairmentof sweating(anhidrosis);b)diminishedlacrimation;c) excessive salivation; d) seborrhea. Heat intolerance: a) intolerance to heat and/or to cold. Miscellaneous signs and symptoms: a) fatigability;b) irisatrophy;c)Hornersyndrome;d)externalocular palsies with diplopia. Dysautonomia in multiple sclerosis: Impaired thermoregulation:Inappropriateincreasesordecreasesinbody temperature (heat sensitivity). Cardiovascular dysfunction:Postural hypotension. Dizziness. Light headedness. Bladder dysfunctions (detrusor-sphincter dyssynergia and detrusor hyperreflexia):Urinary retention. Incomplete emptying. Imminent voiding. Bowel dysfunction: Impaired stomach mobility. Abnormal colonic motor activity. Anorectaldysfunctions:a)constipationand/or fecal incontinence. Sexual dysfunctions:Impotence. Alter orgasmic capacity. Lower libido. V. CRANIAL NERVES SYNDROMES Thecranialnerves(CN)providesensoryandmotor innervations for the head and neck, including general and special sensory and voluntary and involuntary muscle control. CNhavebothsensory(afferent)andmotor(efferent) components.Individualnervemaybepurelysensory,purely motor or mixed. CN carry five distinct modalities (three sensory, two motor): Somaticsensory(whichperceivestouch,pain, temperature,pressure,vibration,proprioceptive sensation). Visceralsensory(whichperceivessensoryinput,except pain, from viscera). Specialsensory(whichperceivessmell,vision,taste, hearing, balance). Somaticmotor(whichinnervatesthemusclesthat develop from somites and from brachial arces). Visceralmotor(whichinnervatestheviscera,including glandsandallsmoothmusclesparasympathetic efferent).Olfactory nerve syndromes:Olfactorydisorders: Changes in olfactory function frequently go unnoticed and often do not present to a clinician. However,olfactioniscriticallyimportantforsafety, nutritional status and quality of life. Olfactorydysfunctioncanbethepresenting sign/symptomofneurodegenerativedisease(e.g.: Parkinsondisease,Alzheimerdisease)oranintracranial mass lesion. Disorders can manifest as: Anosmia ( total loss of smell). Hyposmia (partial loss of smell). Dysosmia (distortions of odorants). Phantosmias ( spontaneous olfactory hallucinations). Foster Kennedy syndrome: Optic atrophy in the ipsilateral eye. Papilledema in the contralateral eye. Central scotoma in the ipsilateral eye, Anosmia ipsilaterally. Etiology: Optic nerve compression. Olfactory nerve compression. Increasedintracranialpressuresecondaryofafrontal lobe tumor, meningioma or plasmacytoma in olfactory groove. Kallman syndrome: Hypogonadotropic hypogonadism. Hyposmia or anosmia. Optic nerve syndromes: Optic nerve: Visioniscriticalforhumanfunctionand,thereforevisual loss, which can be sudden or gradual and may or may not be associated with pain. Theintraorbitalportionissurroundedbythe subarachnoidspaceanddurathatextendfrom intracranial cavity. Optic neuropathy: Anterior ischemic optic neuropathy (AION): AIONincludesinflammatorydiseasesofthebloodvessels thataffecttheopticnerveheadandcauseswellingofthe optic disc. Sudden rapid visual loss in one eye. The vast majority of AION are nonarteritic (NAION):Diabetes mellitus. Elevated intraocular pressure. Hypercoagulate states.Drop in blood pressure. Onset of AION or NAION is in patients over 50 years. Optic neuritis: Inflammationofopticnerve,whichisassociatedwith swellinganddestructionofmyelinsheathcoveringthe optic nerve. Youngadults,usuallyfemales,aremostcommonly affected. Symptomsinaffectedeyeincludepainoneyemovement, suddenblurredorfoggyvisionanddecreaseincolor vision (especially red). Opticneuritis,whencombinedwiththepresenceof multiple demyelinating white mater brain lesions on MRI, issuspiciousformultiplesclerosis(clinicallyisolated syndrome). Compressive optic neuropathy: Tumors, infections andinflammatory processes can cause lesions within the orbit and, less commonly, optic canal. Theselesionsmaycompresstheopticnerve,resulting optic disc swelling and progressive visual loss. Patientsoftenhavebulgingouttheeye(proptosis)with mildcolordeficitsandalmostnormalvisionwithdisc swelling. Etiology:Meningiomas. Hemangiomas. Lymphangiomas. Inflammatory orbital pseudotumori. Metastasis. Multiple myeloma. Thyroid ophthalmopathy. Infiltrative optic neuropathy: Theopticnervecanbeinfiltratedbyavarietyof processes, including tumors, inflammation and infections. Tumors thatinfiltrate the optic nerve can be:Primary(opticgliomas,capillaryhemangiomas, cavernous hemangiomas).Secondary(sarcoidosis,metastaticcarcinoma,naso-pharyngeal carcinoma, lymphoma, leukemia). Traumatic optic neuropathy: Theopticnervecanbedamagedwhenexposedtodirect or indirect injury. Directopticnerveinjuriesarecausedbytraumatothe headororbit(e.g.:bulletthatphysicallyinjurestheoptic nerve). Indirectinjuries,likeblunttraumatotheforehead transmitforcetotheopticnervewithouttransgressing tissue planes. Themostcommonsiteofinjuryoftheopticnerveisthe intracanalicular portion of the nerve. Mitochondrial optic neuropathies: GeneticmutationsinmitochondrialDNA,vitamindepletion, alcohol and tobacco abuse and use of certain drugs can cause derangementsinefficienttransportofmitochondria,which can cause a primary or secondary optic neuropathy. Nutritional optic neuropathies: Monthsofdepletionareusuallynecessarytodeplete stores of most nutrients. Patientswhosufferfrommanynutritionaloptic neuropathymaynoticethatcolorsarenotasvividor bright as before and that the color red is washed out. Undernourishedpatientsoftensufferfrommanyvitamin andnutrientdeficienciesandhavelowserumprotein levels. Theopticneuropathyassociatedwithperniciousanemia andvitaminB12deficiencycanevenbeseeninwell-nourishedindividuals(e.g.:gastricbypasssurgerymay alsocauseavitaminB12deficiencyfrompoor absorption). Peripheralneuropathyisoftenseeninpatientswith nutritional optic neuropathies. Toxic optic neuropathies: Etiology:Methanol intoxication. Ethylene glycol. Ethambutol. Amiodarone. Tobacco exposure. Hereditary optic neuropathies: Theinheritedopticneuropathiestypicallymanifestas symmetric bilateral central visual loss. Opticnervedamageinmostinheritedopticneuropathies is permanent and progressive. Lebershereditaryopticneuropathyisthemostfrequent occurring mitochondrial disease and this inherited form of acute or subacute vision loss predominantly affects young males. Optic atrophy (OA): OAisthefinalcommonmorphologicendpointofanydisease process that causes axon degeneration in the retinogeniculate pathway. Clinically,OAmanifestsaschangesinthecolorandthe structureoftheopticdiscasdissociatedwithvariable degrees of visual dysfunction. Pathologic classification of OA:AnterogradedegenerationWalleriandegene-ration (e.g.: toxic retinopathy, chronic simple glaucoma).Retrogradedegeneration(e.g.:opticnervecompre-ssion); Transsynaptic degeneration (e.g.: occipital damage). Ophthalmoscopic classification of OA: PrimaryOA(e.g.:tabesdorsalis,pituitarytumor,optic nervetumor,traumaticopticneuropathy,glaucoma, Lebersdisease,ischemicdamage,drugintoxication, multiple sclerosis)SecondaryOA(e.g.:papillitis,papilledema intracranialhypertension). Etiologic classification of OA:Hereditaryatrophy(e.g.:Lebersdisease,Behrs disease). Consecutiveatrophy(e.g.:chorioretinitis,pigmentary retinal dystrophy, cerebromacular degeneration) Circulatory atrophy (e.g.: ischemic optic neuropathy in centralretinalarteryocclusion,incarotidartery occlusion and in cranial arteritis).Metabolicatrophy(e.g.:thyroidophthalmopathy, juvenilediabetesmellitusWolframsyndrome, nutritional amblyopia, toxic amblyopia, tobacco excess, methyl- alcohol, ethambutol, sulphonamides).Demyelinating atrophy (e.g.: multiple sclerosis, Devics disease). Pressureortractionatrophy(e.g.:glaucoma, papilledema). Postinflammatoryatrophy(e.g.:opticneuritis, perineuritissecondarytoinflammationofthe meninges, sinus and orbital cellulites). Traumaticatrophy(e.g.:opticnerveavulsionand transection, optic nerve sheath hematoma, optic nerve impingement from a penetrating foreign body or bony fragment). Idiopathic atrophy. Neuromyelitis optica (NMO): NMO is an autoimmune inflammatory disorder. Clinically: Optic neuritis. Transverse myelitis. Ocular motor nerves syndromes: Disordersthatproducedysfunctionofoculomotornerves (cranialnervesIII,IVandVI)maybelocatedanywherefrom the ocular motor nuclei to the termination of the nerves in the extraocular muscles within orbit. Cranial nerve IIIThe oculomotor nerve: Itentersthelateralwallofcavernoussinusanddivides intoasuperiorandinferiorbranchasitenterstheorbit through the superior orbital fissure.Cranial nerve III palsy: Interpedunculardamagetotheoculomotornervemaybe partial or complete. Damage of its subarachnoid portion may occur as:Isolatedpupillarydilatationwithreducedorabsent light reaction (exceptionally rare). Ophthalmoplegiawithpupillaryinvolvement (common). Ophthalmoplegiawithnormalpapillarysizeand reactivity (rare). Opthalmoplegia with pupillary involvement : Ipsilateral ptosis. Ipsilateraldilatedpupil(mydriasis)withminimallyor absentreaction to light. Affected eye is in divergent or temporal position. External or divergent strabismus out and down. Horizontal crosseddiplopia (horizontal heteronymous diplopia).Ipsilateraltherewillbelimitationofelevation, depression and adduction.Cranial nerve IVThe trochlear nerve:It is the only nerve to arise from the dorsal aspect of brain stem. It enters to the lateral cavernous sinus and then enters the orbit through the superior orbital fissure. Cranial nerve IV palsy: Paralysisofthetrochlearnerveisfarlesscommonlythan paralysis of either the oculomotor or abducens nerves. Trochlear nerve palsy can be partial or complete. Clinically:Vertical strabismus. Verticaldiplopia(isgreatestindowngazeandtothe opposite side. Thepatienthavearotationalandoutwardpositionof affected eye, particularly when the eye is in abduction.Themostpatientswithtrochlearnervepalsyhave torticollis(tilttheheadtothesiteoppositethe paralyzed superior oblique muscle. Cranial nerve VIThe abducens nerve: It enters the cavernous sinus lateral to the internal carotid arteryandfinallyenterstheorbitthroughthesuperior orbital fissure. Cranial nerve VI palsy: Locationandcourseofabducensnerve,ratherthanits length,arethemajorfactorsthatleadtoitsfrequent involvement. Abducens nerve palsy can be partial or complete, Clinically:Horizontaluncrosseddiplopia(direct,homonymous diplopia) which worsens at distance. The patient will have an abduction in the involved eye(internal or convergent strabismus)The head is compensatory rotated to the affected eye. Etiology of ocular motor nerves palsy: Aneurysmsusuallyarisefromjunctionoftheinternal carotid and posterior communicating arteries. Aneurisms located at top of basilar artery.Aneurismslocatedatthejunctionofbasilararteryand superior cerebellar artery. Carotid-cavernous sinus fistula. Tumors or other compressive lesions. N.B.:diabetesmellitus,oftenproduceanoculomotor nerve palsy that spares the pupil. Fisher syndrome (FS): FS is characterized by: Relatively symmetrical external ophthalmoplegia. Limbataxiasevereenoughtocauseproblemswith ambulation. Areflexia. Cerebrospinalfluid:albumino-cytologicaldissociation with elevated protein level, without increased cell count.N.B.: FS is a variant of Guillain-Barr disease. Trigeminal nerve syndromes: Thetrigeminalnerveisthebiggestcranialnerveandit carriessensationfromthefaceandmucosalsurfaces,cornea andsupratentorialdura,aswellasprovidingmotor innervations to the muscles of mastication. Thetrigeminalnervehas3mainbranches:ophthalmic (V1), maxillary (V2) and mandibular (V3). V1leavesthecranialcavitythroughthesuperiororbital fissure, V2 through the foramen rotundum and V3 through the foramen ovale. Thefirst-ordercellbodiescarryingmodalitiesofpain, temperature,pressureandlighttouchinall3branches arelocatedintrigeminal(gasserian)ganglioninMeckels cave (near the petrous apex of temporal bone). Thetrigeminalnerveanditsbranchesmediatethe afferentlimbofcornealblinkandlacrimalreflexesand both afferent and efferent limbs of the jaw-jerk reflex. Primary trigeminal neuralgia (classical, typical): Paroxysmal episodes of intense facial pain that last from a fewsecondstoseveralminutes,affectingoneormore divisions of trigeminal nerve. Painisgeneratedspontaneouslyorbytouchingatrigger area. Attacksofpainislikestabbingelectricshocks,burning, crushing or shooting. Wind, loud noises, chewing or talking can aggravate facial pain, Paintendstooccurincycleswithremissionslasting months or even years. Approximately 90% of trigeminal neuralgia is unilaterally. Painusuallyinvolvesasingletrigeminaldivision (frequently the second or third divisions). Attacks are stereotyped in the individual patient. Between attacks there is no pain. There is no clinically evident sensory or motor deficit.Not attributed to another disorder. Neurovascularcompressionisnowacceptedasbeingthe commonest cause of trigeminal neuralgia unresponsive to medical therapy. Secondarytrigeminalneuralgia(incontextoftrigeminal palsy):Generally,indistinguishablefromclassicaltrigeminal neuralgia. Paroxysmal attacks ofpain with or without persistence of aching between paroxysms. Loss of facial sensation. Paresis of both masseter and pterygoids muscles. Corneal reflex is diminished or abolished. Etiology of trigeminal neuralgia and trigeminal palsy: Trigeminalnervesymptomsaremostoftenfoundin association with other clinical features. Neurovascular compression. Tortuousbranchesoftheposteriorcirculationvessels (e.g.: superior cerebellar artery). Trigeminalneurinomas. Acustic neurinomas. Meningiomas. Arachnoid cysts. Epidermoid cysts. Carotid aneurisms. Cerebellopontine angle tumors. Metastatic tumors. Granulomatous or inflammatory diseases. Cavernous sinus syndromes. Atypicaltrigeminalneuralgia(Type2trigeminal neuralgia, Atypical facial pain ATFP): ATFPisasyndromeencompassingawidegroupoffacial pain problems. ATFP,oftendescribedasburning,aching,crampingoras migrainous neuralgia, occurs on one side of the face, often intheregionofthetrigeminalnerveandcanextendinto the upper neck or back of the scalp. Althoughrarelyassevereastrigeminalneuralgia,facial painiscontinuousforATFPpatients,withfew,ifany periods of remission. ATFPcanbebilateral,thoughthecharacterofpainis usually different on two sides at any time. Ophthalmoplegicmigraine(nowisconsideredacranial neuralgia) presents long-lived severe headache, followed byathirdor,muchmorerarely,sixthorfourthnerve palsy. Depressionandanxietyarefrequentlycomorbidwith ATFP. Etiology:Vascular compression. Post herpetic neuralgia. Atypical odontalgia. Infections of the sinuses. Raederparatrigeminalsyndrome(RPS)=Raederpara-trigeminal neuralgia: Main clinical features: Severe,unilateralfacialpainandheadachein distributionoftheophthalmicdivisionoftrigeminal nerve. Horner syndrome (oculosympathetic palsy). Limitedornodisturbanceofsweatingoverthe ipsilateral face. Occasionalinvolvementoftheparasellarnerves (second, third, fourth and sixth cranial nerves). Cavernous sinus syndrome (CSS): Cavernoussinusesarepaired,venousstructureslocatedon either side of the sella turcica. Theyreceivevenoustributariesfromsuperiorand inferiororbitalveinanddrainintosuperiorandinferior petrosal sinuses. Cavernoussinuscontainsthecarotidartery,its sympathetic plexus and the oculomotor nerves(III, IV and VI). Inaddition,theophthalmicbranchandoccasionallythe maxillary branch of the fifth nerve traverse the cavernous sinus. Thenervespassthroughthewallofthesinuswhilethe carotid artery passes through the sinus itself. CSSconsistofvariouscombinationsofoculomotorpalsies and sensory loss in the first (occasionally second)divisions of thetrigeminalnerve,usuallyaccompaniedbysignsof increased pressure or inflammation of venous sinus. Cranialnervesareaffectedfirstononesideonly,butany oftheprocessesthatinfiltrateorobstructthesinusmay spread to the other side. Clinically: Unilateral and isolated III, IV or VI cranial nerve palsy. Combination patterns of ophthalmoplegia. Painful ophthalmoplegia. Proptosis(pulsatingexophthalmossuggestsadirect carotid-cavernous fistula). Ocular and cranial bruits. Conjunctival congestion. Ocular hypertension. Anesthesia in the ophthalmic division of the trigeminal nerve (V1). Decreased or absence of corneal reflex. Possiblyanesthesiainthemaxillarydivisionofthe trigeminal nerve (V2). Hornerssyndromeorthepupilinmidpositionand nonreactiveifbothsympatheticsandparasympa-thetics systems are affected. Cavernous sinus tumors: Cavernoussinustumorsarethemostcommoncauseof CSS. Metastaticlesions(mostoftenfrombreast,prostateor lung): Isolated or combined ophthalmoplegia. Painful ophthalmoplegia. Anesthesia in the ophthalmic nerve. Pituitary tumors:Isolatedorcombinedophthalmoplegia(lateral extension). Endocrine signs as acromegaly, galactorrhea. Unilateral or bilateral visual field defects. Primarytumorsincludes:a)meningiomasorneuro-fibromas;b)locallyspreadingtumorsfromnaso-pharyngeal carcinoma or pituitary tumors. Cavernous sinus aneurysms: Carotid-cavernousaneurysmsdonotinvolveamajorriskof subarachnoid hemorrhage. Theirrupturecanresultindirectcarotid-cavernousfistulas, which may lead to cerebral hemorrhage. Theseaneurysms,whicharemorefrequentintheelderly population, present with indolent ophthalmoplegia. Carotid-cavernous fistulas (C-C fistulas): C-C fistulas are of 2 types:Directfistulasoccurifthecarotidarteryand cavernous sinus are in continuity with high blood flow (venouspressureincreases)andmanifestwithabrupt onsetofmassiveandpulsatileproptosis,chemotic conjunctivalinjection,lidcongestion,bruitandthrill, visualloss,ocularhyperpension,opticneuropathy, opticdiscedema,retinalvenouscongestion,retinal hemorrhage and ophthalmoplegia. Indirectfistulas(duralarteriovenousfistulae)occur withcommunicationbetweencavernoussinusand duralbranchesofinternalcarotidartery,external carotidarteryordualsupplyfrombotharteries (fistulousconnectioniswithinthewallofthe cavernoussinus)withlowbloodflow;b)insidious onset, mild orbital congestion, proptosis and low or no bruit;c)lesionsmayfluctuateandmayresolve spontaneously. Carotid sinus thrombosis: Inadditiontolocal(paranasalsinusesand/ororbital cellulitis)andsystemicinfection,thefollowingmaybe seen: Isolated or combined ophthalmoplegia. Painful ophthalmoplegia. Orbital congestion. Visual loss;Unilateral optic disc edema. Signs of meningeal irritation. Etiology: Primaryintracranialtumors(meningiomas,neuro-fibromas, chondromas). Localized spread tumor (nasopharyngeal, pituitary). Metastatic tumors (brest, prostate, lung). Cranio-cerebral trauma. Carotid-cavernous aneurysms. Carotid-cavernous fistulas. Miscellaneousinflammatorysyndromes:a)Tolosa-Hunt syndrome; b) herpes zoster; c) sarcoidosis. Tolosa-Hunt syndrome (THS): Clinically: Unilateralacuteretroorbitalorperiorbitalpain (gnawingorboringpain),whichcharacterizesthe onset of the disorder. Ophtalmoparesis(variouscombinationsofocular motornervepalsies)orophthalmoplegia(diplopia usually follows the onset of pain).Papillary dysfunction (oculosympathetic paralysis). Sensory loss in the distribution of the ophthalmic (V1), withlossoftheipsilateralcornealreflexand occasionallymaxillary(V2)divisionofthetrigeminal nerve. Intracranial extension of the inflammation into orbit at theorbitalapexcanoccur(rare)andcanaffectthe maxillary(V2)andmandibular(V3)branchesofthe trigeminal nerve, the optic nerve and the facial nerve;Lidswellingandmildproptosismayresultiftheorbit is affected. Spontaneous remissions and exacerbations. Etiology:Nonspecificinflammation,granulomatousornon-granulomatous, within the cavernous sinus or superior orbital fissure. International Headache Society criteria for THS: One or more episodesof unilateral orbital pain lasting for an average of 8 weeks if left untreated.Third,fourthand/orsixcranialnervepalsy,which begins with two weeks of the onset of orbital pain. Symptoms that resolve within 48-72 hours of initiation of steroid therapy.Exclusionofotheretiologiesbyappropriate investigation, including neuroimaging. Facial nerve syndromes: Thefirstbranchofseventhcranialnerveisthegreater superficial petrosal nerve.Thisbranchtravelstosphenophalatineandpterygopalatine ganglionandcarriesparasympatheticfiberstoinnervatethe lacrimal gland of the eye. Thegeniculateganglioncontainingthecellbodiesof general somatic afferent and special visceral efferent neurons is located in the temporal bone within facial canal. Thefacialnerveexitthecraniumthroughthestylomastoid foramen and enters to parotid gland. Facial nerve palsy (FNP): FNP is defined as anunilateral facial nerve paralysis. FNP is usually acute in onset. FNP is characterized by:Facialdrooping(droopingeyelidandcornerofthemouth) on the affected half. Mild to moderate to severe weakness of facial muscles. Difficulty in drinking, chewing and blowing. Drooling of saliva on the affected side. Trouble speaking. Inability to close the eye on the affected side. Discomfort or pain behind the ear on the affected side. Increased sensitivity to noises in the ear of the affected side. Impaired sense of taste in 2/3 of the tongue for sweet, sour and salt. Dryness of eye or mouth. Excess tear formation in the eye on affected side. Etiology: Idiopathic (Bells palsy). Trauma. Herpes zoster oticus (Ramsay Hunt syndrome). Acute and chronic otitis media. Mastoiditis. Lyme disease. Mononucleosis. Diabetes. HIV infection. Autoimmune disorders. Sarcoidosis. Ramsay Hunt syndrome (RHS): RHSisaperipheralfacialnerveimpairment(motor and/orsensory)duetovaricella-zostervirus,withor without associated rash and is associated with otologic manifestationsotherneurologiccomplications, including cranial polyneuropathy or meningitis. RHS is a specific form of herpes zoster that often presents withpre-eruptive(pre-herpetic)pain,allodinia,burning oritchinggenerallylocalizedtotheearandmastoid region. Facialpalsymayprecede,occursimultaneouslywith,or follow erythematosus maculopapular rash. Asmallpatientswithfacialpalsyassociatedwith varicella-zoster infection do not have a rash (or at least no rash in the expected location in the internal auditory canal or on the tympanic membrane). Facialpalsycanbeassociatedwithdecreasedlacrimation and decreased taste (dysguesia) on the anterior two third of the tongue. RHSismorelikelythanBellpalsytobeassociatedwitha complete clinical facial paralysis. OtologiccomplicationsinRHSincludeotalgia,tinnitus, sensorineuralhearingloss,hyperacusis(dysacusis), vertigo, nystagmus and skew deviation with diplopia. RHSmayoccurasacranialpolyneuropathy,involving especially cranial nerves VII and VIII, but also III, V, VI, IX, X, XI and XII, plus C2-C3 sensory dermatomes. Etiology:Varicella-zosterinflammationofthegeniculate ganglion (geniculate neuralgia) and of the skin .Melkersson-Rosenthal syndrome (MRS): MRS is characterized by the triad:Recurrent and sometimes bilateral facial palsy.Recurrent swelling of orofacial structures.Furrowed tongue. Etiology:Noncaseousgranulomaswithperivascularand lymphatic inflammatory cell infiltration. Glossopharyngeal nerve syndromes: Theninthnerveispredominantlysensorynerve,butalso contains some motor and parasympathetic fibers. Therootofninthnerveleavestheskullthroughthe jugular foramen. Thesuperiorandpetrosalgangliaofninthnervearein the jugular foramen. Glossopharyngeal palsy: Isolatedglossopharyngealneuropathyisrareaslesions often involve other cranial nerves in close proximity (VIII, X, XI and XII). Quality of speech: a) nasal; b) guttural. Dysfunction of the secretory parotid gland.Isolatedpalsyofninthnervecanoftenbeasymptomatic, duetoredundantinnervationsoftargetstructuresbythe other cranial nerves. Clinically: Difficulty swallowing. Impairment of taste over the posterior one third of the tongue for bitter. Impaired sensation over the posterior onethird of the tongue, softpalate and posterior pharynx. Absent gag reflex. Glossopharyngeal neuralgia (GPN): GPN is a rare pain syndrome, primarily affectsthe elderly and is severe and paroxysmal. Sharp, stabbing pulses of pain in the back of the throat and tongue, the tonsil and middle ear. The excruciating pain of GPN can last for a few seconds to a few minutes. Paroxysmalpainmayreturnmultipletimesinadayor once every few weeks. Trigger factors:Swallowing. Drinking cold liquids. Talking. Coughing. Clearing the throat. Touching the gum inside the mouth. GPNcanbeassociatedwithcardiacdysrhythmia,bradycardia,hypotensionandevenasystoleand subsequent syncope. Thiseffectissimilartothatseenincarotidsinus massageforthetreatmentofsupraventricular tachycardias(massagingthecarotidsinuscausesa hyperstimulation ofcranial nerve IX afferent pathway, resultinginanexaggeratedparasympatheticvagal efferent response). Inanatypicalglossopharingealneuralgia,painmay radiateintheface,forehead,hypopharynx,larynxand/or external ear canal. Etiology:Microvascular compressions. Eaglessyndrome(cranialnerveIXhyper-excitability syndrome caused bycompression of the nerve against an elongated of fractured styloid process or acalcified stylohyoid ligament). Cerebellopontine angle tumors. Parapharyngeal space lesions or carcinoma. Metastasis to petrous temporal bone.Posttonsillectomy. Nasopharyngeal carcinoma. Posterior fossa arteriovenous malformation. Vagus nerve syndromes: Thevagusnerveexitsthebrainstemjustbelowthe glossopharyngealnerveatthepontomedullaryjunction, traversesthecerebellopontineangleandexitsthecranium through the jugular foramen. Innervatesallstriatedmusclesoflarynxandpharynx except for stylopharyngeus muscle (innervated by IX) and tensor veli palatine muscle (innervated by V3). Sensoryinputfromlarynx,pharynx,externalauditory canal,lateraltympanicmembraneandposteriorfossa meningeal layers are mediated by the vagus. Visceralafferentinformationisconveyedbyvagusnerve from thoracic and abdominal viscera. Vagusnervedeliversparasympatheticfiberstothe thoracicandabdominalvisceraaswell,inadditionto larynx and pharynx. Vagal and superior laryngeal neuralgia: Thetwosomaticsensorybranchesofvagusnerve,the auricularbranchandthesuperiorlaryngealnervecanbe the site of a pain syndrome. Clinically: Paroxysmsofshock-likepaininthesideofthethyroid cartilage,pyriformsinus,angleofthejawand,rarely,in the ear. Occasionally, the pain radiates into the upper thorax or up into the jaw. Thetriggerzoneisusuallyinthelarynxandattacks areprecipitatedbytalking,swallowing,yawningor coughing. Swallowsyncopeorunconsciousnessisarare complicationproducedbyavasovagalreflex,with resulting cardiac inhibition. Unilateral vagus nerve paralysis: Hemiparesis of soft palate with hypotonia. Lueta is deflected by the healthy side of soft palate. Troubleofswallowingliquidsandtheywillenterthe nasopharinx or trachea. Thevocalcordontheinvolvedsideisparalyzed (recurrent laryngeal nerve paralysis). Voiceisbitonal,hoarseornasal(recurrentlaryngeal nerve paralysis). Hemianestesiaofsoftpalateandoftheupperthirdofthe anteriorandposteriorpillarsandcorrespondinghalfof the pharynx. Lossofvelopalatinreflexandofvomitingreflexonthe affected side.Loss of sensitivity to external auditory meatus and behind the ear pavilion. Bilateral vagus nerve paralysis: Serious disturbances for liquid swallowing. Pronounced dysphonia that can go up to aphonia. Autonomic disorders:Tachycardia or bradycardia. Severe respiratory disorders with bronchoplegia. Bilateralrecurrentlaryngealnerveparalysisproduces paralysisofbothvocalcords,withawhisperingvoice, stridor and even death due to tracheal obstruction. Etiology of uni- and bilateral vagus nerve paralysis: Meningitis. Carotid aneurysms. Neoplasms. Trauma. Diphtheria. Surgery of thyroid neoplasm. Cervical adenopathy of any cause. Aortic aneurysm. Mediastinal tumors. Accessory nerve syndromes: ThecranialcomponentofcranialnerveXIrapidlyjoinsthe vagusnerveandservesthesamefunctionasothervagal nerve fibers. Incontemporarydiscussionsoftheaccessorynerve,the commonpracticeistodismissthecranialpartaltogether, referringtotheaccessorynervespecificallyasspinal accesory nerve. Accessory nerve paralysis: Atrophyandparalysisofbothsternocleidomastoidand trapezius muscles. Asymmetric neckline. Drooping shoulder. Winged scapula. Weakness of forward elevation of the shoulder. Etiology: Injury of the spinal accessory nerve. Radical neck surgery. Cervical lymph node. Hypoglossal nerve syndromes: The cranial nerve XII is purely motor in function. Itmovesandaltertheshapeofthetonguebyproviding ipsilateral motor innervation to the intrinsic and extrinsic tongue muscles. Unilateral hypoglossal paralysis: Unilateral hypoglossal nerve paralysis is uncommon. Clinically: Ipsilateral tongue weakness. Deviationtowardstheaffectedsideontongue protrusion. Ipsilateraltongueatrophy(withscallopingor accentuation of midline groove). Ipsilateral fasciculation of the tongue. Bilateral hypoglossal nerve paralysis: Clinically: Bilateral tongue weakness. Tongue atrophy and flaccidity.Inabilitytomovethetonguefromsidetosideor vertically. Multiple cranial nerve syndromes: Clinical features depend on cranial nerves involved. Rochon-Duvigneaudsyndrome=Superiororbitalfissure syndrome. Cranial nerves involved: III, IV, V(1st division), VI. Ophthalmoplegia. Pain and hypoesthesia in the first division of V. Exophthalmos. Vegetative disturbances. Foix-Jefferson syndrome = Cavernous sinus syndrome. Cranial nerves involved: III, IV, V1, VI. Painful ophthalmoplegia. Exophthalmos. Gradenigo-Lannoissyndrome=Apexofpetroustemporal syndrome. Cranial nerves involved: V, VI. Trigeminalneuralgia. Sensorimotor disturbances. Diplopia. Negri-Jacod syndrome = Petreosphenoidal region syndrome. Cranial nerves involved: II, III, IV, V, VI. Ophthalmoplegia. Amaurosis. Trigeminal neuralgia. Avellis-Longhi syndrome = Jugular foramen syndrome. Cranial nerves involved: IX, X. Paralysis of one vocal cord. Paralysis of pharynx. Paralysis of soft palate. Loss of gag reflex. Vernet syndrome = Jugular foramen syndrome. Cranial nerves involved: IX, X, XI. Dysartria. Dysphagia. Weaknessofsternocleidomastoidandtrapezius muscles. Loss of gag reflex. Tapiasyndrome=Jugularforamen+hypoglossalcanal syndrome. Cranial nerves involved: X, XII. Paralysis of the pharynx, larynx and tongue. Sicard-Collet syndrome = occipital condyles syndrome. Foramen jugular syndrome plus paralysis of XII. Cerebellopontine angle syndrome: Cranial nerves involved: V, VII, VIII, IX to XII. Deafness. Vertigo. Nystagmus. Raised intracranial pressure. Brain stem symptoms. Garcin syndrome = Hemibasal syndrome. Cranialnervesinvolved:ItoXIIononesideornearlyall unilateral cranial nerves. Garcin syndrome in its complete form is very rare. There must be at least 7 ipsilateral cranial nerve palsies as the basis for the diagnosis of the Garcin syndrome. Usuallysomenervesandinvolvementofcontralateral nerves can be found. Usuallylackofpyramidalsignsoranyriseofintracranial pressure. Etiology: Neoplasm at base of skull. Paraneoplasticsyndromewithmultiplecranialnerve palsies. Inflammatory lesions at the base of the skull. Fractures of the base of skull. Complications of surgery and radiofrequency lesions. Vascular diseases. Infections. Pachymeningitis. Wagener granulomatosis. Hyperostossis of the skull. Gullain-Barr disease. Metabolic disorders. Idiopathiccranial neuropathy. VI. SPINAL CORD SYNDROMES Spinalcordisastructureofcentralnervousplacedinthe vertebralcanalwhichbeginsattheoccipitalboneandextends downtothespacebetweenthefirstandsecondlumbar vertebrae. The spinal cord has three major functions:Serveasaconduitformotorinformation,whichtravels down the spinal cord. Serveasaconduitforcordsensoryinformation,which travels up the spinal cord. Serve as a centre for coordinating certain reflexes. Theventral(motor)anddorsal(sensory)nerveroots combine to form spinal nerves, one on each side of the spinal cord and exit the intervertebral foramina. Eachsegmentofspinalcordisassociatedwithapairof ganglia,calleddorsalrootganglia,whicharesituatedjust outside of spinal cord. These ganglia contain cell bodies of sensory neurons. Axonsofthesesensoryneuronstravelintospinalcord, via the dorsal roots. Ventralrootsconsistofaxonsfrommotorneurons,which bringinformationtotheperipheryfromcellbodieswithin CNS. Thegraymatter,inthecenterofthecord,isshapedlikea butterflyandconsistofcellbodiesofinterneuronsand motorneurons.Italsoconsistofneurogliacelland unmyelinated axons.Projections of gray matter are called horns.Together,thegrayhornsandgraycommisureformthe gray H. Thewhitematterislocatedoutsideofgraymatterand consist almost totally of myelinatedmotor and sensory axons grouped into tracts. Intheupperpartofthevertebralcolumn,spinalnerveexits directlyfromthespinal,whereasinthelowerpartofthe vertebralcolumn,spinalnervespassfurtherdownthe column before exiting. The human spinal cord can be anatomicallydivided into 33 spinal segments based on the origins of the spinal nerves: lateral(DL)lowermotorneuronsintheventralhorn, whichareinvolvedindistallimbcontrol(theseDL neurons8cervicalsegmentsforming8pairsofcervical nerves: C1spinalnervesexitcolumnbetweenocciputandCI vertebra. C2nervesexitbetweenposteriorarchofC1vertebra andlamina of C2. C3-C8spinalnervesthroughintervertebralforamen (IVF)abovecorrespondingcervicalvertebra,withthe exception of C8 pair which exit via IVF between C8 and T1 vertebra. Thoracic segments forming 12 pair of thoracic nerves and exitspinalcolumnthroughIVF,belowcorresponding vertebra T1-T12. Lumbarsegmentsforming5pairsoflumbarnervesand exitspinalcolumnthroughIVF,belowcorresponding vertebra L1-L5. Sacralsegmentsforming5pairsofsacralnervesandexit spinal column through IVF, below corresponding vertebra S1-S5. Coccygeal segments( a number of 3) joined up becoming a single segment forming 1 pair of coccygeal nerves and exit spinal column through the sacral hiatus. There are two regions where the spinal cord enlarges: Cervicalenlargementcorrespondsroughlytothe brachialplexusnerves,whichinnervatetheupperlimb andincludesspinalcordsegmentsfromaboutC4to T1(the vertebral levels of the enlargement are roughly the same). Lumbosacralenlargementcorrespondstothe lumbosacralplexusnerves,whichinnervatethelower limbandcomprisesthespinalcordsegmentsfromL2to S3 (the vertebral levels of the enlargement are T9 to T12). Somatosensory organization: Spinothalamic tracts (anterior and lateral). Dorsal column tract. Spinocerebellartracts (anterior and posterior). Allsensorypathwaysusethreedifferentneurons (primary,secondary,tertiary)togetinformationfrom sensory receptors at the peripheryto the cerebral cortex. Inallpathways,primarysensoryneuroncellbodiesare foundinthedorsalrootgangliaandtheircentralaxons project into the spinal cord. Motor organization: Corticospinaltract(pyramidalsystem)isdividedintwo differenttracts:a)lateralcorticospinaltract;b)anterior corticospinal tract. Lateralcorticospinaltractdescendsinthelateralcolumn andcontainsupperneuronalaxonswhichsynapse ipsilateralondorsalarefoundspecificallyonlyinthe cervical and lumbosacral enlargements). Anteriorcorticospinaltractdescendsipsilaterallyinthe anteriorcolumn,wheretheaxonsemergeandeither synapseonlowerventromedial(VM)motorneuronsin the ventral horn ipsilaterally or decussateat the anterior white commisure where they synapse on VM lower motor neurons contralaterally (the VM lower motor neurons are locatedthroughoutthespinalcordandcontrolthelarge, postural muscles of the axial skeleton). Extrapyramidal tracts are: a) rubrospinal; b) vestibulospinal;c) tectospinal; d) reticulospinal. Rubrospinaltractdescendswiththelateral corticospinal tract. Tectospinal,vestibulospinalandreticulospinaltracts descendipsilaterallyintheanteriorcolumnbutnot synapse across theanterior white commisure. ExtrapyramidaltractsonlysynapseonVMlower motor neurons ipsilaterally. Theterminal portionofthespinalcordiscalledtheconus medullaris. Thecaudaequina(horsestail)isthenameforthe collectionofnerves(nerverootsL1-L5andS1-S5)inthe vertebral column that continue to travel through the vertebral columnbelowtheconusmedullaris(locatedat~L1level and end at ~L2-L3).The cauda equina forms as a result of the fact that spinal cord stopsgrowinginlengthataboutagefour,eventhoughthe vertebral column continues to lengthen until adulthood. Thisresultsinthefactthatsacralspinalnervesactually originate in the upper lumbar region. Spinal cord transection syndrome: Spinal shock: Rapidandcompletelossofvoluntarymovementand sensationfrom levels below the cord lesions. Flaccid, massive, total and homogeneous tetraplegia, if the lesion is on cervical segments. Flaccid, massive, total and homogeneous paraplegia , if the lesion is on thoracic segments. Upperlimitofanesthesiascorrespondtothelevelof lesion. Signs of affected lower motor neuronat the level of lesion. Autonomicdisturbances:Initially,retentionofurineandfeces(sinceascending sensorypathwaysareinterruptedthereisno awareness of bowel or bladder fullness). Cutaneousbloodvesselsintheareasbelowthelesion do not respond to hot or cold stimuli. Anhidrosis,paroxysmalcardiorespiratorydisorders (inability to regulate heart rate and blood pressure). Trophicdisorders(muscleatrophy,oedema,galloping bedsores). The spinal shock duration can vary between 3 to 6 weeks. Spinal automatism: Asspinalshockfadesitmaybereplacedbyheightened flexorreflexactivity(e.g.:Marie-Foixretractionsign=pressureonthetoesorvigorousplantarflexionatthe ankle leads toflexion at the hip and knee andto attempts fordorsiflexionoftheankle)inwhichexaggerateddeep tendonreflexesandBabinskisignoccurinresponseto noxious or even trivial stimuli. Amassreflexmaydevelopinwhichslightstimulielicit severe bilateral spasms of the arms and legs accompanied by evacuation of the bowel and bladder, profuse sweating and even priapism (a sustained reflexogenic erection). Automaticreflexactivityisalsoheightenedandsofilling ofthebladderorrectummayresultinincreasedseating, flushingoftheface,piloerection,shivering,slowingofthe pulse and elevation of blood pressure. Afteraperiodoftimethesegmentalreflexarcsreappear andbecomesupersensitivetosegmentalsensory information, the effects of which easily spread to adjacent cordlevelsandthereflexresponsesarenowoperating without the usual controls . SpasticparalysisbeginswithBabinskisignandlaterthe otherssignsappear(e.g.:increasedmuscletonesometimesinflexion,heighteneddeeptendonreflexes andlossofsuperficial(abdominalandcremasteric) reflexes below the level of lesion. Loss of all sensation bilaterally below the level of the lesion (proprioception,vibratorysense,tactilediscrimination, pain, temperature, light touch and visceral sensibility). Involuntary and unconscious voiding.Etiology:Traumatic spinal injuries. Spinal tumor. Vascular disorders. Spinal epidural hematoma. Spinal abscess. Intervertebral disk herniation. Transverse myelitis. Topographic diagnosis: Cervical: C1/C2: will often results in loss of breathing, necessitating mechanical ventilators or phrenic nerve pacing. C3:typicallyresultsinlossofdiaphragmfunction, necessitating the use of ventilator for breathing. C4:resultsinsignificantlossoffunctionattheshoulder and biceps. C5:resultsinpotentiallossoffunctionattheshoulders and biceps and complete loss of function at the wrists and hands. C6:resultsinlimitedwristcontrolandcompletelossof hand function. C7/T1:resultsinlockofdexterityinthehandsand fingers, but allows for limited use of arms. Thoracic: T1toT8:resultsintheinabilitytocontrolthe abdominal muscles with trunk instability. T1toT12:resultsinpartiallossoftrunkand abdominalmuscle control. Lumbosacral: Decreasedcontrolof:a)thehipsandlegs;b)urinary and defecation systems. Lateralhemisectionspinalcordsyndrome(Brown Squard syndrome): The Brown Squard syndrome is characterized by: Ipsilateraluppermotorneuronsyndromebelowthe level of lesion. Ipsilateralanteriorhornandrootssyndromesatthe level of lesion. Ipsilateralposteriorhornandrootssyndromesatthe level of lesion. Ipsilaterallossofconsciousproprioceptionand discriminative touch. Contralaterallossofpain,temperatureandnon-discriminative touch below the level of lesion. Etiology:Extramedullary trauma. Extramedullary tumor. Extramedullary spinal vascular malformation. Anterior hemisection spinal cord syndrome =~ anterior artery syndrome: Anterior spinal cord syndrome is characterized by: Bilaterallyanteriorhornssyndromeatthelevelof lesion. Quadriparesis/paraparesisbelowthelevelofthelesion. Lossofpainandtemperaturesensationatandbelow the level of the lesion. Retained proprioception and vibratory sensation. Etiology:Disc herniation. Anterior spinal artery occlusion. Aortic dissection. Posterior hemisection spinal cord syndrome = ~ posterior artery syndrome: Very rare condition: Lossofproprioception,vibrationsensationandepicritic sensation (e.g.: stereognosis, graphestesia). Motor function, sense of pain and sensitivity to light touch remain intact. Etiology:Posterior spinal artery occlusion. Combined spinal cord syndromes: Posterior and lateral columns syndrome: Subacute combined degeneration: Paresthesias of the feet. Loss of proprioceptive and vibration sense. Sensory ataxia. Upper motor neuron syndrome. Etiology:Vitamin B12 deficiency. Vacuolar myelopathy. Extrinsec cord compression. Combined anterior horn cell + pyramidal tract syndrome: Amyotrophic lateral sclerosis (ALS) syndrome: Upper motor neuron syndrome. Lowermotorneuronsyndromewithlesionsatthe anterior horn cell level.Aran-Duchenne syndrome: Form of ALSwith upper limbs onset. Bilateralmuscleatrophiesandmuscularfasciculationsat upper limbs, predominant at hands and at 1/3 distal level of forearms. Muscular spasticity in different degrees, hyperreflexia and Babinski sign. Theprogressofmuscleatrophyinduces,indifferent phasesofdisease,particularaspectsofthehands(e.g.: simianhandtoclawhand,preacherhand,puppet hand or cadaveric hand. Combinedposteriortract+spinocerebellartract pyramidal tractsyndrome = Friedreich ataxia. Loss of position sense, discrimination and stereognosis. Spinal ataxia. Rombergs sign. Later, spastic paraparesis. Combinedposteriorcolumns+posteriorroots+ autonomic system syndrome = tabetic syndrome. Lancinating pains in the legs. Severe painful crisis (e.g.: glossodynia, epigastric pain) Impaired vibration and position sense. Decreased tactile localization. Temporal and spatial disturbance (loss of coordination). Hypotonia of skeletal musculature. Wide-based and slapping gait. Sensorygaitataxia(worseindarknessorwitheyes closed). Areflexia of patellar and ankle stretch reflexes. Rombergs sign. Argyll Robertson pupil. Bladder incontinence and loss of sexual function. Combinedcentralspinal+anteriorhorn+pyramidal tract+ autonomic syndrome = syringomyelic syndrome. Bilateralvest-likelossofpain,temperatureandnon-discriminative touch. Preservationofproprioception,vibrationand discriminative touch. Abnormal body temperature or sweating. Trophic disturbances of the skin. Segmentalneurogenicatrophy,paresisandareflexia (Aran-Duchenne syndrome) at the level of upper limbs.Spastic paraparesis below the level of damage. Scoliosis. Neuropathic artropathy (Charcot joint) in the shoulders. Abnormal boweland bladdercontrol. Cauda equina syndrome: Cauda equina syndrome is a serious neurologic condition: Earlybilateralandasymmetricalradicularpaininthe distributionofthelumbosacralroots,increasedby Valsalva maneuver. Flaccid,hypotonic,amyotrophic,areflexicparalysis(true peripheral-type paraplegia). Absence of the Achilles reflexes (S1-S2 roots). Thepatellarreflexes(L2-L4roots)haveavariable response. Lateasymmetricalsensorylossinsaddleregion, involvingtheanal,perinealandgenitalregionsand extendingtothedorsalaspectofthethigh,the anterolateral area of the leg and the outer aspect of the foot. Late sphincter and sexual dysfunctions:Autonomousneurologicbladder(urinaryretention and post-void residual incontinence). Decreasedanalmuscletoneanddefecationsensation (constipation, faeces incontinence). Erection and ejaculation impaired less often. Etiology:Lumbar spine trauma. Spinal epidural hematoma. Central disk herniation (L4/L5 or L5/S). Spinal stenosis. Primary or metastatic tumors. Pagets disease. Ankylosing spondylitis. Spinal epidural abscess. Inflammatory demyelinatingpolyneuropathy. Conus medullaris syndrome: Clinically: Spontaneouspainis:a)uncommon;b)relativelymild;c) bilateral and symmetrical; d) perineum and thighs. Sensory findings: a) presents early; b) saddle distribution; c) bilateral and symmetrical. Motorfindings:a)symmetricalorasymmetricalmild lowerextremitiesweakness;b)poorrectaltone;d) absent muscle atrophy. Reflex changes: a) Achilles reflex absent; b) patellar reflex normal. Sphincter dysfunctions: a) present early; b) severe; c) absent anal and bulbo-cavernosus reflex. Sexual dysfunctions: a) impaired erection and ejaculation. Etiology: the same diseases as in cauda equina syndrome. VII. BRAIN STEM SYNDROMES The brain stem is the posterior part of the brain which is located caudal to the diencephalon, ventral to the cerebellum and rostral to the spinal cord. Thebrainstemprovidesthemainmotorandsensory innervationstothefaceandneck(viacranialnucleiandcranial nerves (CN): III, IV,V, VI, VII, VIII, IX, X, XI and XII). The brain stem includes:Midbrain (mesencephalon). Pons (part of metencephalon). Medulla oblongata (myelencephalon). Medial structures of brain stem:Motor pathway.Medial lemniscus. Medial longitudinal fasciculus. Motor nucleus and nerve. Periaqueductal gray matter. Central tegmental tract. Reticular formation. Lateral structures of brain stem:Spinocerebellar pathway. Spinothalamic pathway. Sensory nucleus of cranial nerve V. Sympathetic pathway; Reticular formation.Thebrainstemisanextremelyimportantpartofthebrain as the nerve connections of the motor and sensory systems of themainpartofthebraintoorfromtherestofthebody (corticospinaltract,theposteriorcolumn-mediallemniscus pathway, spinothalamic tract and spinocerebellar tract). The brain stem plays also an important role in:Regulation of cardiac and respiratory function. Pain sensitivity control. Maintaining alertness, awareness and consciousness; Regulation of the sleep cycles. The brain stem syndromes general rules:Pathwaysandtractspassthroughtheentirelengthofthe brainstemandcanbelinkedtomeridiansoflongitude whereasthevariouscranialnervescanberegardedas parallels of latitude.Establishingofintersectbetweenmeridiansoflongitude and parallel of latitude it is possible to establish the site of the lesion. Lesionsofmedialstructures:a)contralateralweakness;b) contralateralproprioception/vibrationloss;c)ipsilateral internuclearophthalmoplegia;d)ipsilateralcranialnerve function loss. Lesionsoflateralstructures:a)ipsilateralataxia; b)contralateralpain/temperatureloss;c)ipsilateral pain/temperaturelossofface;d)ipsilateralHorner syndrome. LesionsofthefourCNofmedullaoblongata:a)glosso-pharingeal (IX) ipsilateral pharyngeal sensory loss;b) vagus(X)ipsilateralpalatalweakness;c)spinalaccessory (XI)ipsilateralshoulderweakness;d)hypo-glossal(XII) ipsilateral weakness of tongue. Lesions of the four CN of pons: a) trigeminal (V) ipsilateral facialsensoryloss;b)abducens(VI)ipsilateraleye abductionweakness;c)facial(VII)ipsilateralfacial weakness; d) auditory (VIII) ipsilateral deafness. LesionsoftwoCNofmidbrain:a)oculomotor(III)eye turnedoutanddown;b)trochlear(IV)eyeunabletolook down when looking towards nose. Alternatin