Cranial nerve examination is a part of neurological examinations where 12 cranial nerves are examined in sequences.
12 pairs of Cranial Nerves
OOO Timro Tyo Aakha Fikka Vo Gajal Varera Aau Hai
Olfactory Nerve (I)
First, take consent in all examinations:
Check Nasal patency=>Close eyes =>Place strong stimulus
Stimulus is:
- Soap
- Lemon
- Garlic
- Cardamom
(soap, lemon, garlic, cardamom) are stimulants used in olfactory examinations
Check Bilaterally and compare
Optic Nerve (II)
Optic nerve examinations are discussed in the following four headings:
Visual acuity
Check in Snellen’s chart
Visual Acquity= Distance/Smallest letter distance
Distance is generally kept at 6 meter
Check is done by both Right eye and Left eye
After 1/60 visual acquity==>Do Finger counting test ==>Hand movement test ==> Perception of light
Pocket carrying: E chart (Tumbling E-chart)
Field of Vision
Check-in 1-meter distance
Stretch hand: from left, right, above, and down
Color vision
Check-in Ishihara chart
Pupillary Reflexes
In Dark Room=>Look for the response of pupil=> Normal is Constriction
Look for consensual reflexes also
Accommodation reflex: distance vision to orbit
Oculomotor, Trochlear and Abducens (III, IV, VI)
Inspection:
Any palpebral fissure, look for Ptosis
Fix the head and Check the movement of eyes in all directions
Superior oblique muscle is supplied by the Trochlear nerve (IV), the Lateral rectus is supplied by Abducens (VI), and the rest are supplied by the Oculomotor
SO4+LR6, Rest 3
Trigeminal Nerve (V)
Sensory
Test all divisions of the trigeminal nerve i.e.
- Ophthalmic division
- Maxillary division
- Mandibular division
Motor
Examine muscle of mastication for any motor deficits.
- Massector
- Pterygoid
- Buccal
Facial Nerve (VII)
Sensory evaluation:
- Wipe the tongue first and then evaluate every portion of the tongue
- Sugar(sugar), Bitter(quinine), Salt(table salt) and Sour(lemon)
Schermer’s test
See for Bells phenomena
Look for lagopthalmus
To check Facial muscles: Ask the patient to whistle
UMN vs LMN
Vestibulocochlear (VIII)
Rinne’s test
Check for Air conduction vs Bone conduction (By 128 Hz tuning fork)
Normal: Air conduction is better than bone conduction
Weber test:
The sound heard equally on both sides
Vestibular test
See for nystagmus
Calorie test
Glossopharyngeal Nerve (IX)
Sensory
Posterior 1/3rd sensory testing
Motor:
- Palatal reflex
- Gag reflex: Contraction of Post-pharyngeal (Normal)
Vagus Nerve is also intact if the gag reflex is present and normal
Spinal accessory nerve (XI)
See prominence of SCM muscle and Trapezius muscle
Check motor/power of muscle
Hypoglossal Nerve (XII)
Inspection:
See deviation of tongue, atrophy, fasciculation
Palpation:
Provide pressure by tongue on the mouth.
See also: Sensory Examination
See also: Motor Examination
See also: Neurological Examination
