brain power! “ any fool can know. the point is to understand.” -albert einstein chapter 8
TRANSCRIPT
BRAIN POWER!
“Any fool can know. The point is to understand.”
-Albert Einstein
Chapter 8
CHAPTER 8
DISEASES OF THE NERVOUS SYSTEM
Neurological Diseases
PNS
Anatomy of the Nervous System
• Central Nervous System (CNS)– Brain, spinal cord
• Peripheral Nervous System (PNS-Links CNS to body)– Cranial nerves (from brain)– Peripheral nerves (from spinal cord)
• Autonomic nervous system controls smooth muscle and cardiac muscle – Parasympathetic vs. Sympathetic Nervous system
• Somatic (voluntary) system – skeletal m.
Cranial nerves
NUMBER NAME TYPE KEY FUNCTION
I Olfactory S Smell
II Optic S Vision
III Oculomotor M Eye movement, pupil size, focusing lens
IV Trochlear M Eye movement
V Trigeminal B Sensations – head & teeth; chewing
VI Abducent M Eye movement
VII Facial B Face and scalp movement, salivation, tears, taste
VIII Vestibulocochlear S Balance, hearing
IX Glossopharyngeal B Tongue movement, swallowing, salivation, taste
X Vagus B Sensory from: GI, respiratory; Motor: larynx, pharynx, parasympathetic, abdomen and thoracic
organs
XI Accessory M Head movement, accessory motor with vagus
XII Hypoglossal M Tongue movement
Mneumonics
• Olfactory, Optic, Oculomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accessory, Hypoglossal
– “Oh, Oh, Oh, To Touch And Feel Various Girl's Very Angelic Hands”
– “Some Say Marry Money, But My Brother Says Big Business Makes Money”
Neurological Exam
• Observe– Attitude, mentation (alert, lethargic, coma, etc),
Gait• Agitation, anxiety• Seizures
– Posture (Higher center)• Upright or sternal• Head tilt (vestibular?VIII)• Wide based stance (ataxia, weakness)
Neuro Exam• Gait– Walking and running on flat, non-slippery surface• Walk slowly back and forth with turns and circles
– Proprioceptive deficits (knuckling)-spinal cord defect– Paresis (weakness)/paralysis (no movement) – cerebral
cortex, brainstem, spinal cord or peripheral spinal nerves or muscles
– Circling/pacing – • Tight circling with head tilt – vestibular (VIII)• With dementia – ipsilateral cerebral cortex
Posterior Paresis
• Reflexes present or exaggeratedin the rear legs if lesion is betweenT3-L3• Reflexes arediminished orabsent in the rear legs if lesion is betweenL4-S2
Neuro Exam– Ataxia/incoordination – cerebellum, vestibular
system, or spinal cord
– Dysmetria - cerebellar• Hypermetria – too long movements• Hypometria – movements too short
http://www.youtube.com/watch?v=0QOKPFMt0Rc&feature=endscreen&NR=1
Neurologic Exam
•Cranial Nerves- I (S) Olfactory: ether /alcohol on cotton—will pull away- II (S) Optic: follow moving objects; drop cotton ball- III (M), IV (M), VI (M) Oculomotor, trochlear, abducent: look up, down, sideways- V (B) Trigeminal: sensory to face, motor to muscles of mastication, weakness in jaw muscles
Neurologic Exam–VII (M) Facial: unilateral droop; drool; no
menace–VIII (S) Vestibulocochlear: balance
(nystagmus, head tilt); hearing– IX (B), X (B), XI (M) Glossopharyngeal, Vagus,
Accessory: swallowing; muscle atrophy–XII (M) Hypoglossal: loss of tongue
movement; unilateral atrophy
Neuro Exam – Cranial Nerves• Blind II• No menace II/VII• Anisocoria II, III• Atrophy of temporal muscles V
• Dropped jaw V• Nares, lip pinch, cornea V
– Inside ear• Lip/ear droop VII• No blink VII• Head tilt VIII
Neuro exam – Cranial Nerves
• Nystagmus VIII• Deafness VIII• Difficulty swallowing IX, X• Loss of gag reflex IX, X• Laryngeal paralysis IX, X• Weakness, asymmetry of tongue XII
Cranial nerve
• http://www.youtube.com/watch?v=S8f9-GPW9IE&feature=related
Female Brain
Male Brain
Neuro Exam
• Postural reactions–Knuckling–Hopping–Wheelbarrowing–Hemiwalking
http://www.youtube.com/watch?v=IXpGX6xhJdM
Knuckling
Neuro Exam• Muscle Tone– Atrophy – occurs slowly from disuse• Rapidly from nerve damage
– Lower Motor Neuron signs – decreased reflexes and muscle tone (spinal cord)
– Upper Motor Neuron – reflexes & muscle tone increased (brain)
– Test by flexing/extending joints
Neuro exam – Spinal Reflexes
• Thoracic limb withdrawal – pinch toe• Patellar – strike patellar ligament – extension of
stifle• Pelvic limb withdrawal – pinch toe • Sciatic – Strike between greater trochanter and
ischium – flexion of stifle and hock• Cranial tibial – strike cranial tibial m just below
proximal end of tibia – flex hock• Perineal – pinch perineum/anus – anal sphincter
contraction, tuck tail• Panniculus – stimulate skin over dorsum just lateral
to vertebral column – twitch of cutaneous trunci m.
Neuro Exam: Upper Motor Neuron vs. Lower Motor Neuron signs
UMNLMN• Muscle tone N or I D• Spinal reflexes N or I D• Motor fxn Spastic Flaccid• Muscle atrophy Mild Severe• disuse neuro• Bladder Tense Flaccid
Patellar Reflex
Patellar Reflex
Reflex examination
• http://www.youtube.com/watch?v=NFqFABsIa7Q&feature=related
Pelvic Limb Withdrawal – Or Not
Panniculus Test