Examination of the Cranial Nerves (I – XII)
Dr. A. Cassim
Stations 1 & 2
At these stations there will be an S.P. and a Clinical teacher.
Delivery Objectives:
1. Demonstrate with a clear commentary the examination of the Cranial
Nerves.
2. Familiarise yourself with the clinical signs and symptoms of disorders of
the cranial nerves that can be detected on your examination of a patient.
Cranial Nerve examination forms part of the routine neurological
examination.
I.
Olfactory Nerve
Not routinely examined, but any disturbance of smell should be enquired about in
the history.
Before applying the test to the patient exclude possible obstruction of the
nasal passages by occluding each nostril in turn and assessing if the patient is
able to breathe in through the nose.
•
•
•
•
•
Patient should be asked to close his eyes
Examiner applies a familiar odour eg. perfume or coffee to patient’s one
nostril whilst closing off the other with his index finger.
The patient is then asked to identify the odor.
The procedure is then repeated with the other nostril.
Each nostril is tested separately.
Disorders of Smell can be due to disorders of the olfactory pathways at the level
of:
- olfactory receptors in nasal mucosa
- neurons of the olfactory bulb
- olfactory tract
- uncus lesions (cause olfactory hallucinations, not anosmia)
II.
Optic Nerve
This skill will be covered in detail in the Ophthalmology skill with Prof.
Welsh
Visual Acuity
This is tested using Snellen’s Chart and ordinary newsprint.
Snellen's chart is imprinted with block
letters that line-by-line decrease in size,
corresponding to the distance at which
that line of letters is normally visible.
Snellen’s Chart
A
N.B. If the patient wears corrective lenses he should be tested both with and
without them
Using Snellen’s Chart:
•
•
•
•
•
•
The patient should be standing / seated 3 m from the chart.
The patient’ is instructe to cover one eye with his hand whilst he is
reads letters pointed to him on the chart up to the lowest line.
If difficulty is experienced reading a selected line the patient is asked to
attempt the one immediately above.
The procedure is repeated for the opposite eye.
Each eye is tested separately.
The visual acuity is reported separately for each eye.
Recording the visual acuity:
Visual acuity is recorded as a fraction. The numerator indicates the distance (in
metres) from the chart which the subject can read the line. The denominator
indicates the distance at which a normal eye can read the line. Normal vision is
3/3.
A pocket screener used at the bedside can be substituted for the Snellen’s
chart. Pocket screener should be held at a distance of 30 cm. At this distance
the letters are equivalent to those on Snellen's chart.
Visual Fields
This is tested by Confrontation Tests.
•
•
•
The patient is instructed to cover e.g. the right eye and look into the
examiner’s left eye with the examiner’s right eye also covered.
The examiner is seated / standing roughly at the same level as the patient
and at an arm’s length away.
Starting at the periphery of each quadrant of vision the examiner moves
his finger or hat pin towards the centre of the patient’s vision.
• The patient is asked to indicate as soon as he sees the finger or hatpin.
• The test is repeated for the left eye.
A red topped hat pin is used for testing the central area of vision and a white
topped one for the peripheries).
B
The test reveals gross field defects only and needs to be confirmed by formal
perimetry if a disturbance is found.
Field defects may be due to disturbances in the visual pathways at any of the
following levels:
Lesion
Optic nerve
Optic chiasm
Optic tract / lateral
geniculate body
Occipital lobe
Field Defect
Partial / complete blindness
in affected eye
Blindness in both temporal visual fields
(bitemporal hemianopia)
Blindness in contralateral half of both visual
fields (hemianopia)
Blindness in contralateral half of both visual
fields (hemianopia)
Ophthalmoscopy (fundoscopy)
The patient’s fundus is examined and observations should include the state of:
•
•
•
•
The
The
The
The
Optic Discs,
vessels,
macula and
periphery of the retina
Note: A short acting mydriatic such as mydriacil can be used to dilate the
patient’s pupil. The patient should be warned that he will experience blurred
vision for a period of time. Establish if the patient will need to drive back home if
he has arrived alone before putting in the mydriatic drops.
III, IV and VI
Oculomotor, Trochlear and Abducens Nerves
The action of these nerves is innervation of the eye muscles and they are
therefore tested collectively as a unit.
Nerve III also supplies fibres to constrict the pupil and to levator palpebrae
superioris which elevates the eyelids.
D
Ocular Movements:
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•
•
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•
The patient is asked to look straight ahead.
The eyes are inspected for alignment (squint, skew deviation),
pupillary size and symmetry, and ptosis.
The examiner instructs the patient to follow his finger as he moves
it
The patient follows the movement of the examiner’s fingers without
moving his head.
The range of ocular movement is assessed in all directions of gaze.
Observe for the presence of nystagmus and diplopia (double
vision).
Note: Brief horizontal nystagmus in the extremes of lateral gaze is normal.
Pupillary Response
To light:
•
•
•
The examination should be conducted in a darkened room.
A light is shone into the patient’s eye and constriction of the pupil is
observed in each eye.
Assessment is made of the pupillary size and shape.
Direct and consensual light reflexes are observed.
To accommodation:
• The patient begins by fixating on a distant object and then changes
his focus to a close object.
• Pupillary constriction is assessed and compared to the other eye.
• Each eye is tested separately.
Disturbances of nerve III result in:
•
•
Ptosis of the lid
An inability to look up, down or medially with the affected eye. The
eye is deviated down and out.
• Dilatation of the pupil (non reactive to light)
Disturbances of nerve IV result in:
• An inability to look downward, especially with the eye turned
inwards.
• The affected eye is deviated upward and outward causing vertical
diplopia.
• Compensary head tilt to the side contralateral to the VIth nerve
palsy
• Difficulty in reading and going downstairs
Disturbances of nerve VI result in:
•
V
An inability to look laterally with the affected eye, resulting in
horizontal diplopia on lateral gaze to the affected side.
Trigeminal Nerve
This nerve innervates the skin of the face, muscles of mastication viz. the
medial and lateral pterygoids, masseters and temporalis and supplies sensory
fibres to the cornea.
E
Facial sensation
•
•
•
The patient’s eyes should be closed.
Different modalities of sensation (light touch, pinprick and warm
and cold objects) are assessed on the face in all 3 divisions of the
trigeminal nerve.
The patient reports each sensation as instructed.
• The sides of the face are compared for sensation perception.
Responses are reported as intact, increased or reduced
Corneal Reflex
•
The patient’s cornea is gently touched with a wisp of cotton wool
approaching from the side.
• A blink reflex is observed for.
Note: Avoid stroking only the sclera
Muscles of mastication
•
•
•
•
The masseters and temporalis muscles are observed for wasting
and palpated with the jaw tightly clamped.
The patient is instructed to bite down hard
The patient then opens the mouth and symmetry of jaw opening is
assessed. Any deviation is noted.
In unilateral paralysis of the muscles of mastication the jaw
deviates to the affected side on jaw opening.
Jaw Jerk (Masseter reflex)
•
•
VII
Next, ask the patient to open the mouth and tap the examiner’s finger
placed above the patient’s chin with a gentle downward strike of the reflex
hammer.
Observe for jaw contraction.
Facial Nerve
The facial nerve supplies motor fibres to the muscles of facial expression and
taste sensation to the anterior part of the tongue.
F
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•
•
•
The patient is instructed to imitate the examiner as he frowns, smiles
and raises his eyebrows.
Symmetry of facial expression is compared.
Strength is tested (eye closure, lip closure)
The patient is asked to shut his eyes tightly while you attempt to open
them.
•
•
•
The patient is asked to puff up his cheeks as the examiner attempts to
deflate the cheeks.
Taste sensation is tested by having the patient identify sugar and salt
placed on the anterior part of the tongue keeping the tongue protruded
until the sensation of taste has been perceived.
The patient should have sips of water between each test.
Weakness of the muscles of the lower part of the face indicates an upper motor
neurone lesion
Weakness affecting the whole face implies a lower motor neurone lesion.
VIII
Vestibulocochlear / Acoustic Nerve
G
This examination with be covered in detail in the E.N.T. skills session.
This nerve comprises 2 parts: the cochlear (hearing) and the vestibular nerves
(balance)
Vestibular nerve
Not routinely tested and requires special equipment (caloric tests)
If the patient gives a history of tinnitus or vertigo vestibular tests are indicated.
Cochlear nerve
The external auditory meatus should be inspected with an otoscope prior to
performing the test to exclude any abnormalities.
The ticking clock test
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•
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Establish the patient’s ability to perceive the sensation.
Compare with your own to establish normality.
The patient’s eyes should be closed.
A ticking clock is placed a few inches away from the ear and moved
further away until the patient can no longer hear it ticking.
The test can also be conducted by starting well away from the ear and
then slowly approaching the ear until the patient first perceives the
sensation.
Weber Test
This lateralizes the hearing.
•
•
•
The base of the tuning fork is placed on top of the patient’s skull and
held firmly in position
The patient is asked where the sound is heard.
The sound is normally heard in the centre/ middle
If the Weber lateralizes to one ear it indicates either a sensorineural hearing loss
in the contralteral ear or a conductive hearing loss in the same ear.
Rinne Test
Compares air conduction with bone conduction using a tuning fork.
Normally air conduction is better than bone conduction.
• The base of a vibrating tuning fork is placed on the mastoid process
• The patient reports when he can no longer feel the vibration.
• The vibrating tuning fork is then brought in front on the ear to assess if
the patient can hear the sound
H
IX
X
Glossopharyngeal and
Vagus Nerves
These are normally tested together.
I
The patient’s voice is assessed for hoarseness and swallowing is observed.
The Gag Reflex
•
The sides of the pharynx are stroked with a spatula and the patient’s
ability to gag is assessed.
The palatal reflex
•
•
The patient can be instructed to say Ahh whilst the examiner observes
the movement of the uvula and compares symmetry.
The sensation of the uvula and pharynx is assessed with a spatula.
J
Symmetrical movement of the uvula, the absence of hoarseness and the ability to
swallow indicates an intact Vagus nerve.
Unilateral palsy causes deviation of soft palate and uvula to the sound side on
saying ahh.
The autonomic functions of the Vagus will not be covered here.
XI
Accessory Nerve
The accessory nerve supplies motor fibres to the sternocleidomastoid and the
trapezius muscles
K
•
•
•
•
The trapezius muscle is palpated for strength
The patient is then asked to shrug the shoulders against resistance.
The patient is asked to flex the neck against resistance
Then the patient is asked to laterally rotate the head against
resistance.
Hypoglossal Nerve
XII
This nerve supplies motor fibres to the tongue.
•
•
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•
The patient is instructed to protrude the tongue
Inspect for wasting and fasciculation.
Any lateral deviation of the tongue is noted.
The strength of the tongue is tested by instructing the patient to move it
from side to side against resistance provided by a spatula or against the
inner side of the cheek.
• Unilateral paralysis causes tongue deviation to the affected side on
tongue protrusion.
L
REFERENCES:
1. Essentials of the Neurological Examination, American Medical
Association
2. The Precise Neurological Examination, University of New York
Medical School,
3. Clinical Examination, Tally and O’Çonnor, Third edition.
4. Hutchinson’s Clinical Methods
5. Macleod’s Clinical Examination.
Acknowledgements to the following sources for images used in this
presentation:
• B- Precise Neurological Exam, American Med. School
• C- Mc Cleod’s Clinical Examination
• D,E,F,G,I,K – American Medical Association, Essentials of the
Neurological Examination
• H,L &J– Univ. of California, ST. Diego
EXAMINATION OF CEREBELLAR FUNCTION
DR. R.M. Alexandrescu
Station 3
At this station there is an S.P. and a Clinical teacher
Station Objective:
1. Demonstrate with a clear commentary the examination of the Cerebellum
2. Revise the anatomy of the cerebellum
The cerebellum is the large brain mass lying dorsal to the pons and medulla
within the posterior fossa.
The cerebellum controls balance and coordination of movement.
It consists of two hemispheres (neocerebellum) united by a narrow middle
part,
the vermis (paleocerebellum). Between the vermis and each hemisphere
lies the
paravermis (intermediate zone).
Phylogenetically, there are three components: the archicerebellum,
palaeocerebellum
and neocerebellum.
1. The Archicerebellum (flocculo – nodular lobe) receives its principal
input from the vestibular nuclei (vestibulocerebellum)
2. Paleocerebellum (the cerebellar midline structures-vermis) receives
projections from the spinal cord (spinocerebellum):
- adjusts the tone and coordination of motor activity in order to
maintain the equilibrium of rest and movement.
E.g. to maintain a posture by standing without any support, change
posture in
walking, running, turning or bending
3. Neocerebellum (the cerebellar hemispheres) lies on a circuit
incorporating the cerebral cortex and the pons.
- reinforces the tonus and coordination of muscular activity when
voluntary
movements are performed.
The fibers projecting in and out of the cerebellum pass through the
superior, middle
and inferior cerebellar peduncles.
THE CEREBELLUM AND ITS CONNECTIONS
The diagram shows the afferent spinal-cerebellar and ponto-cerebellar pathways and the
efferent cerebellar pathways.
Acknowledgements: (Essentials of the neurological examination. A.M.A)
Acknowledgements: Clinical Examination. N J Tally & S O’Connor
The features of cerebellar disease:
-
dysarthria
nystagmus
-
dysdiadochokinesia
ataxia (trunk and limbs)
dysmetria
intention tremor
hypotonia
vertigo
titubation
Dysathria:
Difficulty with articulation
In cerebellar dysathria, the pronunciation is difficult; the rhythm of speech is lost, with
pauses
then accelerates, becomes jerky, explosive and loud. Cerebellar dysarthria is described
as
scanning or staccato speech.
Nystagmus:
Usually jerky horizontal nystagmus with the fast phase towards the side of the lesion.
and increased amplitude on gaze towards the side of the lesion.
Dysdiadochokinesia:
Inability to perform rapid alternating movements.
Ataxia:
Disorderly or uncoordinated movement.
Patients do not present any instability of the trunk in the sitting position (only
if there is a substantial disturbance of midline cerebellar structures)
When walking, the patient will use a wide-base gait and shows caution when turning.
and on walking. This is because most cerebellar fibers cross twice in the brain-stem,
both on entry to, and exit from the cerebellum.
Intention tremor:
Side - to- side tremor on approaching a target.
Vertigo:
A subject sensation of movement
Titubation:
Head tremor
A. Upper limbs:
Coordination is evaluated by testing the patient’s ability to perform rapidly alternating
(RAM) and point-to-point movements correctly (finger-nose-finger test):
1. Rapid alternating movements
2. Finger-nose-finger test
1. Rapid alternating movements (RAM):
There are few tests for RAM:
A. The patient should make rapidly alternating movements, such as patting
his
thighs with his palms and the backs of his hands, by pronating and
supinating the
hands. Once the patient understands this movement, tell him to repeat it
rapidly for
10 seconds. Normally this is possible without difficulty.
B. The patient should make RAM, by patting his thighs with the palmar surface
of the hand in rapid succession.
C. The patient must oppose each finger to the thumb in rapid succession.
D. Ask the patient to place one palm facing upwards and then alternately hit the
palm with the palmar and then dorsal aspects of the fingertips of the other hand as
quickly as possible.
Acknowledgements: Clinical Examination. Macleod’s. Tenth Edition.
Note: Rapidly alternating movements are not only impaired in cerebellar disease but
also in pyramidal and extrapyramidal disease.
2. Finger-nose test (testing for intention tremor)
With the eyes open, the patient touches his nose with his index finger and
then touches the examiner’s outstretched finger.
This action is repeated with increasing rapidity.
The examiner can change the position of his finger.
This test is performed for each hand.
Ask the patient to touch the tip of the nose (A) and the examiner’s finger (B).
Move the finger from one position to another (C, D).
Acknowledgements: Clinical Examination. Macleod’s. Tenth Edition.
Past pointing / overshoot
1. Patient must track the rapid movements of the examiner’s index finger with his
own.
2. While seated the patient is asked to rapidly elevate his extended arms to
shoulder height.
B.
Lower limbs:
Coordination:
1. Heel-shin test
With the patient in supine position instruct the patient to place the right heel
on the left knee
Then ask the patient to slide the heel down the shin to the foot.
Repeat the same movement going back to the starting position at the knee
and down
To the shin several times.
The test is carried out with the other foot.
A. Beginning of the test
B. Normal result.
The hell runs smoothly and straight down the skin.
C. Abnormal result. The heel is ataxic and jerky with oscillations from side to
side whilst sliding down the shin.
2. Toe-finger test:
With the patient in supine position, ask the patient to lift the foot and touch the
examiner’s finger with the big toe.
Look for intention tremor.
3. Foot-tapping test: rapid alternating movements are tested by getting the
patient to
tap the sole of the foot on the ground. Each limb is tested individually. .
Slowness in movements or inability to perform this task may indicate a
cerebellar lesion,
proprioception disturbation, or hemiparesis.
Balance
To achieve balance, 2 out of the 3 following inputs to the cortex must be intact:
1. Visual confirmation of position
2. Non-visual confirmation of position (proprioceptive and vestibular
input).
3. A normally functioning cerebellum.
The Romberg test:
Acknowledgements: www.aafp.com
This test evaluates mainly propioception.
Functions (vermis).
The patient should remove his footwear.
Ask the patient to stand erect with heels together.
Then compare the balance with the eyes open and then closed.
The physician should remain near the patient to prevent injury in case the patient
falls
A normal person may sway slightly with the eyes closed.
In cerebellar ataxia balance is poor with eyes opened or closed.
In sensory ataxia the patient is steady with eyes opened and falls with eyes
closed.
A positive Romberg’s test (losing balance with closed eyes) indicates sensory
ataxia.
Gait is also controlled by the cerebellum and should always be included in the
cerebellar testing.
Gait is evaluated by having the patient walk across the room under observation.
Observe the patient for the base of his stance and gait
Cerebellar disease causes gait ataxia manifesting with a broad based and
unsteady gait...
When the vermis is involved, the patient widens his base and walks with
difficulty.
When the lesion is in the hemisphere you can see a tendency to fall to the
same
Side of the lesion
Heel-toe walking test:
The patient should remove his footwear.
Ask the patient to walk heel-to-toe (tandem gait)
This test evaluates the function of the vermal / midline cerebellar structures.
Acknowledgements: www.aafp.com
Observe the patient rising from the sitting position.for truncal ataxia.
Note gross abnormalities.
Acknowledgements: www.aafp.com
Cerebellar Syndromes
1. Axial /vermal /midline cerebellar syndrome: truncal,gait, stance ataxia
2. Appendicular /hemispheric cerebellar syndrome: limb ataxia (ipsilateral to side of
lesion)
References:
1. Clinical Examination. A systematic Guide to Physical Diagnosis. N.J.Talley&
Simon O’Connor.Fourth Edition.
2. Clinical Examination. Third Edition. Owen Epstein & all. 2003.
3.
Clinically oriented anatomy. Keith L. Moore & Arthur F. Dailey. Fourth Edition.
Deep Tendon & Superficial Reflexes
Dr. A. Cassim
Station 4
At this station there is an S.P. and a Clinical teacher
Station Objectives:
1. Demonstrate with a clear commentary the examination of Superficial and
Deep tendon Reflexes.
2. Recognise abnormal responses and be able to correlate it with the affected
dermatomes.
A somatic reflex arc is the simplest functional unit of the nervous system. A simple
arrangement of elements permits a response to stimuli, where the final element in the
chain is skeletal muscle.
Acknowledgements: Dr. Thomas Caceci
Reflexes have both sensory and motor components (afferent & efferent).
In evaluating reflexes, the part of the body being tested should be relaxed and
the stimuli applied with the same intensity on corresponding sites.
Deep Tendon Reflexes (Monosynaptic reflex arc):
Essential tips when using the patella hammer:
•
•
•
•
•
The patella hammer should be held nearer the end.
The movement as the tendon is being struck with the hammer should be
delivered from the wrist.
The head of the hammer should be allowed to fall with gravity on the
intended forefinger or muscle tendon
An observation of the rapidity and strength of muscle contraction / jerk is
observed.
A comparison is made with the opposite side,
Results are reported as:
Normal / present
Increased / brisk
Decreased / absent, and
graded out of 4.
GRADING OF DEEP TENDON REFLEXES
Grade
Biceps
•
•
•
Interpretation
0 (0/4)
Absent
1+ (1/4)
Slight jerk or a palpable or visible
muscle contraction
2+ (2/4)
A moderate or average jerk
3+ (3/4)
A very brisk jerk
4+ (4/4)
Clonus
Jerk (C5, C6)
Forefinger of one hand is placed on the biceps tendon
The biceps tendon is struck by the patella hammer.
For the corresponding biceps tendon (furthest away from the examiner’s
side) the thumb of the hand may be substituted for the forefinger.
Brachioradialis (Supinator) Jerk (C5, C6)
• The patient’s elbow is flexed and pronated.
• The examiner places two fingers over the lower end of the patient’s radius
just above the wrist.
• The tendon of the brachioradialis is struck on examiner’s two fingers
placed over this area.
Triceps Jerk (C7, C8)
• Examiner supports the wrist with one hand as the forearm is pronated and
resting across the patient’s body
• The triceps tendon is struck with the tendon hammer.
Finger (flexor) Jerks (C8)
Patients holds hand palm upwards, fingers slightly flexed and relaxed. Examiner
places his hand over the patient’s and the hammer is struck over the former’s
hand.
Knee Jerk (L3, L4)
Examiner slides his arms under the patient’s slightly flexed knees and supports
them. The tendon hammer is struck over the infra patellar tendon.
Ankle Jerk (S1, S2)
Patient’s foot is held in mid position at the ankle, whilst the examiner bends the
knee, externally rotates the hip and holds the foot dorsiflexed.
The Archilles tendon is struck with the tendon hammer.
Superficial Reflexes (Polysynaptic reflex arc):
•
•
The patient’s skin is stroked with an object that is moderately sharp but
should not injure the skin (e.g. with the end of the reflex hammer).
The skin response is observed and compared to the opposite side.
GRADING OF SUPERFICIAL REFLEXES
Reflex tested
Result
Upper abdominal reflex
Normal / Absent
Lower abdominal reflex
Normal / Absent
Cremasteric reflex
Normal / Absent
Anal Reflex
Normal /Absent
Plantar Reflex
Down going /up going
Upper Abdominal
•
The examiner strokes the skin just above the patient’s umbilicus on either
side using the object chosen for the examination.
Lower Abdominal
•
The skin below the umbilicus is similarly stroked with an instrument.
Cremasteric
•
Anal
•
The skin of the inner aspect of the thigh is stroked on both sides in a male
patient with the instrument.
Skin close to the anal canal is stroked on either side
Plantar Reflex (Babinski) (L5, S1, S2)
•
•
The patient’s foot should be dorsiflexed at 90 degrees to the ankle.
The examiner strokes the lateral aspect of the patient’s sole with a blunt
instrument such as a car key.
•
•
He then curves the stroke inwards towards the M.T. P. joint before
reaching the toes
An observation is made of the response of the toes at the M.T.P. joint
REFLEXES
Reflex
Normal Response
Biceps Jerk
Contraction of biceps
with flexion of the
forearm at the elbow
followed by
prompt relaxation
Pertinent Central
Nervous System
Segment / Roots
C5, C6
H
Triceps Jerk
Triceps contracts
with elbow extension
C7
I
Brachioradial
is Jerk
Contraction of the
brachioradialis with
flexion of the elbow
C5, C6
Finger Jerks
Slight flexion of all
fingers occurs
C8
Knee Jerk
Quadriceps contracts
causing extension of
the knee
Ankle Jerk
Plantar flexion of the
foot
L2, L3, L4
S1
Upper
abdominal
Umbilicus moves up
and toward area
being stroked
T7 – T9
Lower
Abdominal
Umbilicus moves
down
T11, T12
Cremasteric
Ipsilateral scrotal
elevation
T12, L1
Anal
Skin tenses at the
gluteal area
Plantar
Reflex
(Babinski)
Plantarflexion of the
foes
L4 – S3
Ss
K
REFERENCES:
1. Clinical Examination. Tally & O’Connor
2. Essentials of the Neurological Examination. The American Medical
Association.
3. Veterinary Medicine. Dr. T. Caceci.
Acknowledgements to the following sources for the images used in this
presentation:
H–K
TEXAS A & M University