CRANIAL NERVES AND TESTING

CN I

Olfactory

Afferent - Smell

CN II

Optic

Afferent - Eye sights

CN III

Oculomotor

Efferent - Voluntary movement of Superior/Medial/Inferior Recti, Inferior Oblique.

Autonomic - Eye contraction/dilation.

CN IV

Trochlear

Efferent - Voluntary movement of Superior Oblique

CN V

Trigeminal

Efferent - Mastication muscles (jaw movement)

Afferent - Touch/Pain along the face.

CN VI

Abducens

Efferent - Voluntary movement of Lateral Recti

CN VII

Facial

Afferent - 2/3rd anterior tongue

Efferent - Facial expressions

Autonomic - Lacrimal glands, submandibular glands, sublingual glands.

CN VIII

Vestibulocochlear

Afferent - Balance and Hearing

CN IX

Glossopharyngeal

Afferent - Posterior 1/3rd tongue taste, pain/touch of pharynx and tongue

Efferent - Voluntary muscles of pharynx

Autonomic - Parotid Glands.

CN X

Vagus

Afferent - Pharynx, Larynx, Bronchi

Efferent - Muscles of the palate, pharynx, and larynx

Autonomic - Thoracic and Abdominal Vicera

CN XI

Spinal (Accessory)

Efferent - SCM and Trapezius

CN XII

Hypoglossal

Efferent - Voluntary muscles of the tongue

CN I Testing

Patient has eyes closed and therapist provides various familiar smells

(+) = Inability to provide correct smell

CN II Testing

Utilizing a Snells Chart (working on visual and acuity)

(+) = Inability to read or identify from a reasonable distance

CN III, IV, and VI Testing

H and I and X testing without movement of the head.

III = Vertical, Horizonal, and Upward Looking

IV = Downward and Inward Gaze

VI = Lateral gazing

CN V Testing

Sensation: Patient identifies sharp or dull along the face dermatome distribution.

Motor: Movements of the mandible in protrusion, retraction, and lateral deviation.

CN VII Testing

Sensation: Patient is to taste salty or sweet.

Motor: Patient is to do facial expressions

CN VIII Testing

In a quiet location, therapist is behind the patient and then have ticking noise of around 18-24 inches away from ear. If they cannot hear then it is a positive test.

Can also test balance

CN IX Testing

Gag reflex

Taste test of the posterior tongue aspect.

CN X Testing

Gag Reflex, Say "Ahhh"

If no gag reflex, then carefully assess the movement of the soft palate and uvula.

CN XI Testing

Perform MMT of trapezius and SCM. (+) is inability to maintain resistance.

CN XII Testing

Patient in sitting and then protrudes the tongue.

(+) If the tongue deviates towards the injured side.

CN Red Flags - Dysarthria

Bulbar or Brainstem Dysfunction (speech impairment)

CN Red Flags - Dysphagia

Can lead to pneumonia or aspiration (swallowing impairment)

CN Red Flags - Diplopia

Dictate cranial nerve palsy or aneurysm (double vision)

CN Red Flags - Sudden hearing loss or vertigo

Can dictate verstibular schwannoma or stroke

CN Red Flags - Aniscoria

Can dictate aneurysm or uncal herniation (non-reactive pupils)