EXAMINATION OF NERVOUS SYSTEM

Written by Dr.Md.Redwanul Huq (Masum)
Sunday, 23 December 2012 14:22

Examination of nervous system includes:

1) Higher psychic function,

2) Cranial nerves,

3) Motor,

4) Sensory

5) Signs of co-ordination

6) Involuntary movements

7) Sings of meningeal irritation

8) Romberg’s test

9) Gait.

1) Higher psychic function: (hintsABCDTIMSO)

A : Appearance,

B : Behavior,

C : Concentration, Communication,

D : Disorders of perception, delirium, dementia,

T : Thought,

I : Intelligence, insight,

M : Mood, memory,

S : Speech & language,

O : Orientation about time, place and person.

Concentration:

It is tested by repeating the months in reverse or performing serial sevens (starting at 100 & continuously subtracting 7)

Disorders of perception:

Hallucination: Imaginary perception i.e. apparently normal perceptions occurring

in the absence of appropriate stimulus.

Illusion: False perception i.e. misinterpretations of external stimuli.

Delusion: False beliefs.

Intelligence:

It is tested by asking the patient simple sums.

Insight:

It means self understanding.

Memory:

It is of following types:

a) Long term memory,

b) Intermediate term memory,

c) Immediate memory.

Disorders of Speech:

Disorders of speech include:

a) Dysarthria: Defects of articulation & enunciation of speech.

b) Aphasia: Disturbances of structure & organization of language itself.

c) Too much talk.

d) Too little talk.

2) Cranial nerves:

Examination of cranial nerves are as following-

1) Olfactory nerves:

i) Inspection: By torch-observation of any abnormality in nasal cavity, lateral wall, septum etc.

ii) Questioning to the patient:

a) Are you caught by cold?

b) Do you get any smell?

iii) Clinical examination:

a) Test of sense of smell for each nostril separately by substances present on be

side of the patient (e.g. Soap, flower etc).

b) Sniffing with eyes closed for each nostril (by using pieces of cotton)

2) Optic nerve:

i) Inspection: Size & shape of pupils of both eyes.

ii) Questioning to the patient:

a)Do you have any problem with your vision?

iii) Clinical examination:

a) Visual acuity-

Distant vision – by snellen’s test

Near vision- by fingers.

b) Field of vision- by confrontation test using a finger.

(Distance from patient: about 1 meter).

c) Colour vision: by Ishihara test.

d) Light reflex.

e) Fundoscopy.

3) Oculomotor, 4) Trochlear, 6) Abducent nerves:

i) Inspection: Ptosis, Squint, Size & shape of pupils of both eyes, nystagmus.

ii) Questioning to the patient:

Do you have double vision?

iii) Clinical examination:

Motor: Examination of movement of eyes- by moving the right index finger in

‘H’ shaped pattern.

Reflexes:

1) Light reflexes (Direct & consensual),

– by shining a bright pen torch from the side & from below.

2) Accommodation reflex:

– by asking patient first to look into the distance & then an object held close

to the eyes.

5) Trigeminal nerve:

i) Inspection: Atrophy of temporalis & masseter.

ii) Questioning to the patient:

iii) Clinical examination:

a) Sensory: Light touch (by cotton), Pain (by pin) at-

i) Ophthalmic area: Over supra-orbital margin,

ii) Maxillary area: Over malar prominence,

iii) Mandibular area: Below the angle of mouth.

b) Motor:

i) Clinching (for temporalis & masseter) & palpation of temporalis & masseter.

ii) Side of side movement of mandible (for media & lateral pterygoids)

iii) Depression of mandible against pressure.

c) Reflexes:

i) Corneal reflex: By cotton, from side at sclero-corneal junction.

ii) Jaw jerk.

7) Facial nerve:

i) Inspection:

a) Palpebral fissure,

b) Naso-labial fold,

c) Angle of mouth.

ii) Questioning to the patient:

a) Disturbed hearing,

b) Storage of food at vestibule of mouth.

c) Fall of saliva through angle of mouth.

d) Decreased taste sensation.

iii) Clinical examination:

a) Motor:

i) Transverse wrinkles on forehead.

ii) Closure of eyes against pressure.

iii) Laughing,

iv) Whistling,

v) Blowing out of cheek.

b) Sensory: Testing taste of salt, sour, sweet & bitter (at last).

8) Vestibulo cochlear nerve:

1.Cochlear part-

i) Inspection:

ii) Questioning to the patient:

i) Do you have any problem with hearing?

iii) Clinical examination:

i) Whispering over external acoustic meatus,

ii) Rinne’s test,

iii) Weber’s test.

2.Vestibular part-

i) Inspection: Spontaneous nystagmus,

ii) Questioning to the patient:

iii) Clinical examination:

i) Positional nystagmus (Hallpike’s maneuver),

ii) Oculovestibular reflex / vestibule-ocular reflex/caloric test,

iii) Romberg’s test.

9) Glossapharyngeal nerve & 10) Vagus nerve:

i) Inspection: Position of palate & uvula is checked for these cranial nerves.

ii) Questioning to the patient:

i) Any question to patient- to see the sound is nasal or not.

ii) Do you have nasal regurgitation of fluid or other food.

iii) Clinical examination:

i) Observation of movements of palate & uvula by asking the patient to say ‘aah’.

ii) Gag reflex: Constriction & elevation of pharynx & palate in response to tactile

stimulation to back of the pharynx.

11) Spinal accessory nerve:

i) Inspection: Inspection of trapezius & sternocleidomastoid muscles.

ii) Questioning to the patient:

iii) Clinical examination:

i) For trapezius: At first palpation of trapezius & then examining the power of it

by asking the patient to shrug against pressure.

ii) For sternocleidomastoid: At first palpation of it & then examining the power

of it by asking the patient to rotate the head against pressure on chin.

12) Hypoglossal nerve:

i) Inspection: Observation of tongue for bulk (wasting – in LMN fasciculation (in MND),

tremor (in parkinsonism).

ii) Questioning to the patient:

iii) Clinical examination:

i) Protrusion of tongue- Tongue deviates to affected side in LMN lesion.

ii) Side to side movement of tongue.

iii) Pressing by tongue on cheek against pressure.

iv) Asking patient to say, ‘lah lah lah’ (for hypokinesis).

3)Motor:

a) Inspection:

i) Bulk of the muscle (including wasting),

ii) Fasciculation,

iii) Skin Condition.

b) Others:

i) Palpation of muscle groups.

ii) If wasting is present, measurement of circumference of muscle at a point which

is equidistant on both ides from a bony prominence (e.g. Tibial tuberosity).

iii) Tone of the muscles:

a) Palpation of muscles to see tonicity,

b) Passive movements of joints

In upper limb (UL):Movements of elbow, shoulder, wrist & joints of fingers.

In lower limb (LL): Movements of hip, Knee, ankle & joints of toes.

iv) Power of muscles:

a) Grading of power of muscles:

Grade O: Complete paralysis (no muscle contraction is seen)

Grade 1: A flicker of contraction only, but no movement of joint.

Grade 2: Joint movement when effect of gravity eliminated.

Grade 3: The limb can be held against gravity, but not against the examiner’s resistance.

Grade 4: Limb can be held against gravity plus added pressure, but weakly.

Grade 5: Normal power is present.

b) Power of individual muscle group – by movement of individual muscle group

against pressure.

V) Reflexes:

In upper limb:1) Biceps jerk,

2) Triceps jerk,

3) Supinator jerk,

4) Hoffmann’s reflex.

In lower limb:1) Knee jerk,

2) Ankle jerk,

3) Plantar reflex.

If tendon jerks are exaggerated, then-

1) Ankle clonus,

2) Knee clonus.

4) Sensory:

Tests of sensation are done at first on forehead & then over dermatomes of

upper & lower limbs for-

a) Fine touch (by cotton),

b) Crude touch (by head of pin),

c) Pain (by tip of pin)

d) Temperature (by cool or hot water filled test tube)

e) Two point discrimination (by a two-point discriminator or by an opened out paper clip)

on pulp of index finger & thumb.

f) Vibration sense (by tuning fork)

– At first on forehead, then on great toe, maleolus, tibial shaft, tubial tuberosity & anterior iliac crest.

g) Joint position sense (JPS):

– In upper limb: at distal interphalangeal joint of index finger.

– In lower limb: at interphalangeal joint of great toe.

5) Signs of co-ordination:

a) In upper limb:

i) Finger- nose test,

ii) Dysdiadochokinesis (impaired ability in producing accurate, rapid and regularly

 alternating movements)

b) In lower limb- Heel-shin test,

c) During gait- Heel-toe test.

6) Involuntary movements:

a) Tremor: Rhythmical oscillations.

b) Athetosis: Slow, writhing, distal.

c) Chorea: Jerky, rapid, semi-purposive.

d) Dystonia: Slow, sustained, turning or postural.

e) Myoclonus: Sudden shock-like, non-purposive.

f) Hemiballismus: Proximal, flailing.

7) Signs of meningeal irritation:

a) Neck rigidity (by passive movement of neck),

b) Kerning’s sign.

8) Romberg’s test:

Patient is asked to stand with feet together. At first eyes are open & then closed. Patient fall if not caught with open eyes-if there is cerebellar lesion & patient falls if not caught with closed eyes-if there is

i) Dorsal column lesion or

ii) Vestibular lesion.

9) Gait:

Gait disorders:

1) Spastic gait: Short gait, knee bending absent: UMNL (paraplegia),

2) Hemiplegic gait: Hand flexed, hemi-circle of foot: Stroke.

3) Festinate gait: Short, rapid, shuffling gait, bending forward : Basal ganglia lesion (parkinsonism)

4) Drunken gait: Walk on wide base, tendency to fall on one side : Cerebellar lesion.

5) High stepping gait: Legs are pulled high & pushed forward : Foot drop.

6) High stamping gait: Legs are pulled high & jerks in front with force: Peripheral neuropathy.

7) Waddling gait: Lordosis, tilting on both sides: Proximal muscle weakness (myopathy).

8) Scissoring gait: Cross legged progression: Paraplegia or quadriplegia.

Differences between UMN & LMN type of facial nerve palsy-

UMN type

LMN type

1) Only the lower part of face is involved.

2) No bell’s phenomenon.

3) Taste is not affected.

4) No hyperacusis.

5) Usually associated with hemiplegia.

6) Site of lesion above the facial nucleus, commonly in internal capsule.

7) No facial wasting.

1) Both upper & lower parts are involved.

2) Bell’s phenomenon present.

3) Taste may be affected.

4) Hyperacusis may occur if nerve to the stapedius is involved.

5) Not so.

6) In nucleus & distal to nucleus.

7) May have facial wasting.

Signs of cerebellar lesion-

Hypotonia,

Drunken gait,

Intention tremor,

Dysdiadochokinesis,

Dysarthria,

Pendulus kneejerk,

Nystagmus,

Vertigo.


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