Cranial Nerve Examination

The cranial nerve examination is the assessment of 12 cranial nerves of the body. These cranial examinations include all the motor and sensory evaluations. The cranial nerve is responsible for various functions like smell, sight, hearing, taste, and touch.

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Olfactory Cranial Nerve Examination

During Olfactory Cranial examination, test both perception and identification using aromatic non-irritant materials that avoid stimulation of trigeminal nerve fibers in the nasal mucosa, e.g. soap tobacco. One nostril is closed whereas the persistent sniffs with the other.

Patient Position: Sitting on a Couch

Therapist position: Besides the patient

Instruction to patient: To close one nostril and sniff with the other.

Method

Using aromatic non-irritant frequently used material can be a coffee power. The therapist will take that opened packet near one nostril separately to test the olfactory nerve.

Hypoglossal Cranial Nerve Examination

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient

Instruction to patient: Ask the patient to open their mouth; inspect the tongue

Method

Ask the patient to protrude the tongue. Note any difficulty or deviation. A protruded tongue deviates toward the side of weakness. The non-protected tongue cannot move to the opposite side. Dysarthria and dysphagia are minimal.

Optic Cranial Nerve Examination

The Optic Cranial examination is tested in each eye separately using a Jaeger-type card for near vision, labeled according to size (Normal acuity is between J1 –J4) and Snellen’s wall chart placed 6 feet away at which patient is expected to read the letter(meters).

Patient Position: Sitting on a Couch

Therapist position: Besides the patient

Instruction to patient: Look at the chart and read it out loud.

Method

Test both the near vision and far vision separately with separate charts. For near vision, doctors use Jaeger-type cards. Many doctors carry a pocket Jaeger-type card for patients in the ICU. For far vision, doctors use Snellen’s wall chart.

Note: Measure, Shape, Balance, Response to light: both understudies choke when light is shone in either eye. Response to settlement and meeting: Student narrowing happens when the look is exchanged to a near-point object.

Damage to Optic nerve

In cranial examination, a lesion of the optic nerve will abolish papillary response to light on the same side as well as in the contralateral eyes.

When light is shone in the normal eye, it and the contra lateral pupil will constrict.

Oculomotor (III),Trochlear (IV) and Abducens(VI) Nerves

Patient Position: Supine lying on bed.

Therapist position: Besides the patient

Instruction to patient: To look toward the Torch

Method

When Shine torch light is placed on the affected contralateral pupil constricts (its III nerve intact), Absent or impaired response in the illuminated eye.

When light is shone into the ordinary eye, as it were the understudy on the side constricts.

Damage to Oculomotor (III)

Ptosis: Ptosis: Ptosis is display if the eyelid hangs over the understudy when the eyes are completely open. Since the levator palpebrae muscle contains both skeletal and smooth muscle, Ptosis seen whereas performing cranial examination means either a III nerve paralysis or a thoughtful injury and is more noticeable with the former.

Ocular Movement testing

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient

Instruction to patient: In Cranial examination, Steady the patient’s head and ask him to follow an object held at arm’s length.

Method

Observe full range of horizontal and vertical eye movements.

Cranial examination of eye movement in the six different directions of gaze represents maximal individual muscle strength.

Looking up and out superior rectus
Looking up and in inferior oblique
Lateral movement by lateral rectus
Medial movement by the medial rectus
Looking down and out inferior rectus
Looking down and in superior oblique

Damage to Ocular Movement

Nystagmus: It is a condition in which the normal balance of eye control is upset. When the person slowly tries to drift the pupil in one direction is followed by a fast corrective movement.

Nystagmus is maximal when the eye is turned in the direction of the fast phase. Test as for other eye movements, but remember that ‘physiological ‘nystagmus can occur when the eye deviates to the endpoint of the gaze.

Trigeminal Cranial Nerve Examination

The Trigeminal cranial examination is both sensory and motor fibers tested separately.

Sensory Examination

Test For pain

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient

Instruction to patient: sit still on the stool

Method: Take a blunt pin and prick on various dermatomes of the body for the sensation of pain.

Test for Temperature

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient

Instruction to patient: sit still on the stool

Method: Take a cold object or hot /cold tubes placed on various dermatomes of the body for sensation for temperature testing.

Test for Light touch

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient

Instruction to the patient: sit still on the stool

Method: Take cotton wool and place it on various dermatomes of the body for sensation for light touch testing.

Corneal Reflex Test

Test corneal sensation by touching it with a wisp of wet cotton wools. A blink response should occur bilaterally. This cranial examination testing is the most sensitive indicator of trigeminal nerve damage

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient

Instruction to the patient: still on the stool

Method: With a wisp of wet cotton wool touch the corneal area near the eye. Normally, the person blinks bilaterally. But no blink or unilateral blink represents that there is any trigeminal nerve damage.

Motor examination

Observe for squandering and diminishing of temporalis muscle – ‘hollowing out’ the temporalis fossa.

Ask the understanding to clamp jaws together. Feel temporalis masseter muscle. Endeavor to open the patient’s jaws by applying weight to the chin. Inquire the persistent to open their mouth. If pterygoid muscles are powerless the jaw will veer off to the powerless side, being pushed over by the unopposed pterygoid muscle of the great side.

Jaw Jerk

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient, Place a finger on the chin and tap.

Instruction to the patient: Ask the patient to open their mouth and relax his jaw. With the hammer strict on the chin with a broad area of hammer :

Slight jerk: Normal

Increased jerk: bilateral upper neuron lesion.the

Facial Cranial Nerve Examination

Patient Position: Sitting on a couch or stool

Therapist position: Beside the patient and Place one hand on the head and the other as a supporting the hand.

Instruction to patient: The patient is then instructed to:

Wrinkle your forehead (frontalis)( By looking upward)
Close the eyes while examiner attempts to open them(orbicularis oculi)
Purse lip while examiner presses cheeks (buccinators)
Show teeth (orbicularis oris)

Observe the patient when he talks and smiles, watching for:

Eye closure
Asymmetrical elevation of one corner of the mouth
Flattering of the nasolabial fold

Taste may be tested by using sugar, NaCl. A small quantity of each substance is placed anteriorly on the tongue.

Auditory Cranial Nerve Examination

Auditory Cranial examination has two components: cochlear is responsible for hearing and vestibular is responsible for balance and coordination.

The test is by whispering numbers separately in both ears, if hearing is impaired, examine the external meatus and the tympanic membrane with an auroscope to exclude wax or infection.

There are two tests to differentiate conductive deafness and nerve deafness

Weber test

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient.

Instruction to patient: Sit still with no movement

Hold the base of the tuning fork (512 H) strick on hand and place it against the vertex. Ask patient if the sound is heard more loudly in one ear. Normally patient will have heard the sound in both ears. In conduction deafness, sound is louder in the affected ear since distraction from external sounds is reduced in that ear. In nerve deafness, sound is the louder in the normal ear.

Rinne’s test

Patient Position: Sitting on a couch or stool

Therapist position: Beside the patient and Place one hand on the head and the other as a supporting the hand.

Instruction to patient: Sit still with no movement

Method

Take a tuning fork struck on hand and place the vibrating tuning fork against to mastoid bone. Ask the patient if the note is heard. When the note disappears -hold the tuning fork near the external meatus. The patient should hear the sound again since air conduction is better than bone conduction.

In conductive deafness, bone conduction is better than air conduction.

In nerve deafness, both bone and air conductions are impaired.

Nerve examination of the vestibular component requires specialized investigation which is called Neurotological tests.

Glossopharyngeal Nerve(IX) and Vagus Nerve (X)

These nerves are consider jointly since they are examined together and their actions are seldom individually impaired

Gag reflex testing

Patient Position: Sitting on a couch or stool

Therapist position: Besides the

Instruction to patient: Ask the patient to open their mouth and say “Ah”.

Note – Any asymmetry of palatal movement (X nerve palsy). Compare the sensitivity on each side (afferent route – IX nerve).

A positive test when there is an absent gag reflex means loss of sensation, loss of motor power, and demolish of the taste in the posterior third of the tongue (IX) is impractical to test.

Accessory Cranial Nerve Examination

Sternomastoid

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient, one hand on the side of the head to give resistance.

Instruction to patient: Ask patient to rotate the head against resistance. Compare the power and muscle bulk on each side. Also compared each side. Also, compare each side with patient pulling the head forward against resistance. When left sternomastoid turns the head to the right and vice versa.

Trapezius

Patient Position: Sitting on a couch or stool

Therapist position: Besides the patient, Place both hands on both shoulders.

Instruction to patient: Ask the patient to “shrug” shoulders and to hold them in this position against resistance. Compare muscle power on each side. The patient should manage to resist any effort to depress shoulder.

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