mental status exam and cranial nerves

The Neurological Examination

Dante P. Bornales, MD, MHPEdFellow of the Philippine Neurological Association

In doing the Neuro. Exam., always bear the following in mind:

1. The purpose of the detailed neurological evaluation is to isolatethe “deficits” so that one could make a neurological localization ,reserve the determination of “what is the lesion” after one has correlatedthe findings with the “temporal profile” of the case;

2. The complexity of the procedures relates to the extensiveness of the

functions of the nervous system, it is necessary for a clinician to master the procedure with constant and regular practice so that onecan vary and even short cut the procedures depending on the neurological complaint of the patient;

3. It is necessary to integrate parts of the neurological exam with the other parts of the history and general physical examination

eg.: assess MSE and speech during the interviewevaluate some of the CN exam as one go through the

history and PE

4. During the conduct and in the documentation of the findings, make sure that one’s thinking is organized in the following categories:

I. Cerebral Examination / Mental Status ExaminationII. Cranial Nerve ExaminationIII. Motor System Examination, including CoordinationIV. Sensory System ExaminationV. Muscle Stretch ReflexesVI. Other Significant Neurological Findings

5. In each of the categories, make sure that one compares “symmetry” of the findings;

6. What you will document are the findings, and not conclusions! Avoidusing “normal” blatantly, rather describe objectively what youobserve from the patient;

7. It is better to commit rather than to omit the seemingly insignificantneurological findings; and,

8. “If one doesn’t write anything, one did not do anything” , a thoroughand detailed documentation of the neurological findings is betterthan a lacking neurological evaluation.

The neurological history and the neurological exam findingsshould closely be correlated in order for one to determine

the nature of the lesion, as follows:

Major Neurological Disease Categories:(Adams and Victor’s: Principles of Neurology)

1. Cerebrovascular Diseases (Vascular Diseases)2. Infections of the Nervous System3. Neoplasms of the Nervous System4. Traumatic Injury5. Neurodegenerative Diseases6. Demyelinating Diseases7. Inflammatory Diseases / Autoimmune Diseases8. Congenital / Developmental Diseases9. Metabolic Diseases affecting the Nervous System

Cerebral Examination / Mental Status ExaminationSpeech, Level of consciousness, Attention and Orientation,Memory processing, Calculation, Abstract thinking, Fund ofinformation

Cranial Nerve ExaminationCN I to XII

Motor System Examination, including Cerebellar testsInspection of body position, Involuntary movements, muscle bulk,Muscle Tone, Manual Motor Testing, Coordination and Gait

Sensory System ExaminationLight touch, pain and temperature, position and vibration senses,Descrimination modalities

Muscle Stretch ReflexesDeep tendon reflexes

Other Significant FindingsSigns of meningeal irritation, primitive reflexes, superficial reflexes

The Components of the Neurological Examination

Things needed for the neurological examination

Don’t forget: the ophthalmoscope for fundoscopy

Mental Status Examination

1. SpeechPhonationArticulation

Language Production

2. Level of consciousness3. Attention and Orientation4. Memory processing

Immediate recallRecent MemoryRemote Memory

5. Calculation6. Abstract thinking7. Fund of information

Mental Status Examination

Speech

Phonation - is the production of sounds as the air passes through the vocal cords

Disorder: dysphonia

Articulation- is the manipulation of sounds as it passes through the upperairways by the palate, tongue, and the lips to produce phonemes

Disorder: dysarthria

Language production- the organization of phonemes into words and sentences, and is controlled by the speech centers in the dominant hemisphere

Disorder: dysphasia or aphasia

Phonation

Assessment:- could have been observed during the history-taking- if not, simply ask questions and get him to talk

- in dysphonia:the speech volume is reducedthe voice sounds husky

- dysphonia is usually due to lesion of the recurrent laryngeal nervesrespiratory muscle weakness (eg. GBS)

Articulation

Assessment:

- ask patient to recite tongue-twisting words “Baby hippopotamus”“kapakipakinabang”

- causes of dysarthria:1. Cerebellar dysarthria - speech is slurred (“drunk”)

with scanning quality

2. Extrapyramidal dysarthria - speech is soft and monotonous

3. Pseudobulbar dysarthria - high pitch with a strangulatedquality; sounds like “Donald Duck”

4. Bulbar dysarthria - nasal quality that may worsen as patient continues to talk

Language production

Assessment:

• establish patient’s handedness (dominant hemisphere dysfunction)• listen to the patient’s spontaneous speech, assess the fluency

and content• assess comprehension by observing his or her response to simple

questions

“open your mouth”; “look up to the ceiling”; “protrude yourtongue”

• assess the patient’s ability to name objectseg: show your wristwatch

• assess the patient’s ability to repeat sentences“no ifs, ands, or buts”

• if any of these features is abnormal, consider aphasia/dysphasia

TYPE OF

APHASIA

LESION SPEECH FLUENCY

SPEECH CONTENT

COMPRE-

HENSION

REPE-TITION

Expressive Broca’s area

Non-fluent normal normal Variable

Anomic Angular gyrus

Fluent normal normal normal

Receptive Wernicke’s area

Fluent Impaired Impaired Variable

Conductive Arcuate fasciculus

Fluent normal normal Impaired

Global parietal Non-fluent Impaired impaired Impaired

Classification of Aphasia

Your task: determine the clinical differences of the different typesof aphasia

Level of Consciousness

components: level of arousal (wakefulness)content of consciousness (awareness)

Level of arousal:

AlertObtundedStuporComa

Your task: define the different levels of consciousness

Level of Consciousness

level of arousal (wakefulness)

• alternatively, can be assessed clinically using the“Glasgow Coma Scale”

content of consciousness (awareness)

• alternatively, can be assessed using the “Mini-MentalState Scale”

Appearance and behaviour

- assessment begins as soon as one meet the patient - look for evidences of self-neglect- observe the patient’s responses to questions during

the history-taking- assess the level of comprehension and insights into

his or her problem

Remember: these questions can be incorporated or are alreadyImplied during the “history-taking”!!!

Attention and Orientation

Attention:

First! Assess that the pt’s comprehension is normal Formal assessment is done using serial reversals:

• spell “WORLD” backwards for me, please• can you name the months of the year backwards • can you count backwards from 10

Attention and Orientation

Orientation:

assess the patient’s orientation to time, place, and personask:

• What day of the week is it today?• How long have you been in the hospital?• Can you tell me where are you now?• What city are we in now?• Who is this person? (point to a family member, or nurse)

Remember: these questions can be incorporated or are alreadyImplied during the “history-taking”!!!

Memory Processing

assess: immediate memory recallrecent memory recallremote memory recall

Immediate memory recall

• establish patient’s comprehension and attention

• test for digit span:

“can you repeat these numbers after me (eg. 293, 9785)please”

- start with 2 or 3 figures- avoid recognizable numbers- a normal person can repeat a five- to seven-digitsequence

Memory Processing

Recent memory recall

• ask to recall about politics, social events, sporting events,taking into account his previous premorbid conditionand socioeconomic status

• ask to memorize a short address (ask the patient back to be

assured that it has been registered); distract pt. for about10 min. by continuing with the other parameters of the MSE,then ask him to repeat the statement

Pearl: most individuals can recall all data in 10 min

Memory Processing

Remote memory recall

• ask about childhood, schooling, work history, or marriage/s(you need a third party to confirm/verify information!!!)

Remember: - the questions in the remote memory processing are alreadyimplied during the interview

- immediate and recent memory are usually affected early in dementing diseases, eg. Alzheimer’s disease

- remote memory is relatively sparred in pts. With minordegrees of brain damage, however always affectedin advanced dementia

Calculation

- should be done in the light of pt’s education

Assessment:• give simple addition and subtraction• do – serial of sevens or threes ( subtracting sevens or

threes serially from 100)

• give simple daily-living-problem solving scenarios, eg. “If a kilo of mangoes cost 75 pesos, how muchwill 5 kilos cost?”

Pearl: dyscalculia is a prominent fetaure of Gerstmann’s syndrome (dyscalculia, R-L disorientation and finger agnosia) caused bya dominant hemisphere lesions like stroke

Abstract thinking

- this is tested by asking the patient to interpret commonproverbs:

“ A bird in the hand is worth two in the bush”“ Ang lumakad ng matulin, kung matinik ay malalim”“ Ang hindi lumingon sa pinanggalingan ay di makararating

sa paroroonan”

- this can also be tested by assessing the patient’s abilityto identify similarities between pairs of objects,eg. “cow and dog”, “air and water”

Your tasks: Define and differentiate the following1. apraxia from agnosia2. cortical and subcortical dementia

Cranial Nerve I – Olfactory Nerve

Assessment:

• Ask patients about any recent change in their sense of smell(eg. Anosmia, parosmia)

2. Check for the patency of the nostrils

3. Examine each nostril in turn, using tobacco, coffee, or cinnamon(use colored vials so that patient will not be able to identify thetest agents even before the procedure)

Tip: avoid using irritating substances (ammonia, alcohol) for thesesubstances could stimulate the trigeminal nerve endings, evenin anosmic patients!

Checking for the patency of each nostrils

Examine each nostril with the test agent, preferably with the examinerclosing each of the patient’s nostrils

• Unilateral loss of smell is usually asymptomatic

• Bilateral loss of smell is always associated with an alteredsense of taste

• Always examine the CN I in all patients with persosnality changes,disinhibition, or dementia (frontal lobe involvement), and in all cases of head trauma

Causes of olfactory symptoms:

Anosmiacongenital

nasal sinuses infections/tumorshead injury/cranial injuryfrontal lobe tumorssubfrontal meningiomas

Parosmias (persistent unpleasant smells)nasal infectionshead injurydepression

Olfactory hallucinationstemporal lobe epileptic seizures

Paroxysmal unpleasant smell (burning rubber, gas)psychosis

Cranial Nerve II – Optic Nerve

Examine:

• Visual acuity using the Snellen chartor a near chart

2. Peripheral field of vision by doing the GrossConfrontational Test

3. Do the fundoscopy using the ophthalmoscope

4. Check for reaction of pupils (for CN II and III)

Assessment using the Snellen chart:

• Position the patient 20 ft away from the chart

2. Ask the patient to read the smallest line of print possible,coaxing him to read the next line may improve performance

Ask the patient to cover one eye during the tests for eacheye

3. Determine the smallest line of print from which the patient can identify more than half the letters

4. For those with refractive errors, use a pinhole to correctthe patient’s vision, and record the findings

Assessment using the near chart:

If the Snellen chart is not available, use the near chart. Hold the hand held chart 14 inches away, and do much the same procedure as using a Snellen chart

If the patient is unable to read the largest character, assess his ability to count your fingers at 1 m (report as VA:CF)

If the patient cannot see your fingers, ask him to identify your moving hands (report as VA:HM)

If the patient cannot see hand movements, flash light in front of his eyes (report as VA:LP). If patient is unable to perceive light (VA:NLP), then the patient is medically blind!

The Gross Confrontational Test

1. Sit or stand about 1 m from the patient with your eyes at the same horizontal level

2. Ask the patient to look directly into your eyes and hold your hands halfway between you and the patient

3. Ask the patient to point at your moving finger/s for you to assess his visual fields (Make sure that the examiner’s visual field is normal before the procedure!)

4. The patient’s visual field will match the examiner’s if the head positions are exactly halfway between the examiner and the patient (this is seldom the case)

If a visual defect is detected, test one eye at a time.

In a right temporal field defect, ask the patient to cover the left eye, and with the right eye, to look into your eye directly opposite. Then slowly move a wriggling / moving finger from the defective area toward the better vision, noting where the patient first responds.

Repeat this at several levels to determine the borders.

Your task: review the visual pathway and the visual field defectsthat can be assessed using the Gross Confrontational test

The Fundoscopic examination using the ophthalmoscope

Your task: practice the procedure after the demonstration; makesure that you know how to handle the instrument

before the session ends

This is the area that you will be able to see using your ophthalmoscope

Cranial Nerve II, III – Optic and Oculomotor Nerves

Pupillary Light Reflexes

Ask the patient to fixate on a distant target and shine the light in each eye in turnfrom the lateral side. Observe for the direct and consensual light reflexes

Accomodation Reflex

Cranial Nerve III, IV, VI – Oculomotor Nerve Trochlear Nerve, Abducens Nerve

Inspect the eyes and note for the position of the eyelids and the presence of any strabismus and ptosis

Strabismus is concomitant if it remains constant all throughout the range of eye movement. It is inconcomitant (paralytic) if it varies

Do pursuit and saccadic movements to assess whether the eye movements are conjugate, and to detect diplopia and nystagmus

Pursuit eye movements

Steady the pt’s. head and hold an object (eg. pen) 4-5 cm in front of the eye

Ask the pt. to follow the moving object throughout the range of the binocular vision in the horizontal and vertical planes in an “H” pattern

Assess the smoothness, speed and magnitude of the movements

Saccadic eye movements

Steady the pt’s. head and to look in all directions as quickly as possible. Assess the velocity and the accuracy of the movements

Describe this patient’s EOM paralysis. (The patient was instructed to look downwards!)

Describe this patient’s EOM paralysis. (The patient was instructed to look to the left!)

Describe this patient’s EOM paralysis. (The patient was instructed to look to the right!)

Describe each of the images and discuss the EOM findings

Cranial Nerve V – Trigeminal Nerve

Motor functions of the CN V

Inspect for wasting of temporalis muscle, which produces hollowing above the zygoma

Ask the patient to clench his teeth together and palpate the temporalis and masseter muscles

The pterygoids are assessed by resisting the pt’s. attempts to open his mouth

In unilateral trigeminal lesions, the lower jaw deviates to the paralytic side as the mouth is opened

Sensory functions of the trigeminal nerve

Using light touch, test for the presence and symmetry of the facial sensation

Test for pain sensation using a pin (with blunt end) in the same fashion as you have tested for fine touch

Reserve the tests for temperature and proprioception if there’s an abnormal finding with pain sensation

Sensory testing of the face

Always:

• instruct the patient on what to do before proceeding with test• show the test objects to be used• ask the patient to close his eyes throughout the procedure

Sensory testing of the face – fine touch

Note for symmetry of the sensation by comparing symmetrical dermatomal segments on the face

Sensory testing of the face – pain sensation

Sensory testing of the face – temperature sensation

Corneal Reflex (CN V and VII)

Reserve this procedure if one cannot test for the separate functions of the V and VII cranial nerves!

Cranial Nerve VII – Facial Nerve

Sensory testing for the taste (anterior 2/3 of the tongue has less clinical benefit, thus, it is reserved for special cases

Motor functions of the CN VII

Always check for symmetry!!!

Your task: review the facial muscle innervation and differentiate peripheral from central facial paralysis

Describe the facial paralysis of this patient.

Does he has peripheral or central facial palsy?

Cranial Nerve VIII – Vestibulocochlear Nerve

Clinical bedside assessment of hearing is not sensitive, and can detect only gross hearing loss!

Reserve the oculovestibular reflex (Doll’s eye) in unresponsive patients!

Grossly assess hearing in each ear while masking the hearing in the other ear by occluding the external meatus with your index finger

Test the pt’s. sensitivity by whispering numbers into his ears and asking him to repeat it

Weber testCheck for lateralization of sounds conducted through the bones

Rinne test

Compare air conduction and bone conduction

Cranial Nerve IX, X - Glossopharyngeal Nerve, Vagus Nerve

This is the normal palatal arches as the patient opens his mouth and when he says “ahhhhh”

Note for gag reflex by touching the soft palate or the pharyngeal walls separately

sensory: IXmotor: X

Observe for the patient’s voluntary swallowing

Describe the direction of the uvula

Cranial Nerve XI – Spinal Accesory Nerve

The function of the trapezius is assessed by asking the pt. to elevate his shoulders, first without, then with resistance

The function of the sternocleidomastoids is assessed by asking the patient to turn his head and applying resistance, note for the bulk and strength of the muscles

Always check for symmetry of the bulk and strength

Cranial Nerve XII – Hypoglossal Nerve

Describe the findings in this patient when you ask him to protrude his tongue

End of segmentEnd of segment

mental status exam and cranial nerves

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