Cranial Nerves Clinical Assessment The FACE of Cranial

Cranial Nerves Clinical Assessment The “FACE” of Cranial Nerves

I Olfactory II Optic III Oculomotor IV Trochlear V Trigeminal VI Abducens VII Facial VIII Acoustic IX Glossopharyngeal X Vagus XI Spinal Accessory Xii Hypoglossal Cranial Nerves

Cranial Nerves l When assessing the cranial nerves, there are 4 items the examiner must know: – – Function Name & Location of Primary Nuclei Testing Signs of Dysfunction

Cranial Nerves l CN I – Olfactory Nerve – – – Function: special sensory Name & Location of 1 o Nuclei: cribriform plate Testing: l l l – Use 2 -3 vials of familiar odors Test one nostril at a time with patient’s eyes closed Use least irritating scent first and allow the patient to rest in between vials Signs of Dysfunction: anosmia

Cranial Nerves l CN II – Optic Nerve – – – Function: special sensory Name & Location of 1 o Nuclei: retina Testing: l l – Snellen Eye chart Fundus Exam Visual fields via confrontation Pupillary Light reflex Signs of Dysfunction l l Blindness Loss of pupillary constriction (sensory)

Cranial Nerves l CN III – Occulomotor Nerve – – Function: somatic & visceral motor Name & Location of 1 o Nuclei: l l – Testing: l l l – Somatic Motor Nucleus: EOM Visceral Motor: pupillary constriction & accommodation Six Cardinal Fields of Gaze Pupillary Light reflex: (motor) Accommodation Signs of Dysfunction: l l Eye turned down & out w/ ptosis Mydriasis, Loss of accommodation, Diplopia

Cranial Nerves l CN IV – Trochlear Nerve – – – Function: somatic motor Name & Location of 1 o Nuclei Testing: l – Six Cardinal Fields of Gaze Signs of Dysfunction: l l Vertical diplopia Excycodeviation of the eye

Cranial Nerves CN V – Trigeminal Nerve l – Function: l l – Branchial motor – mastication General Sensory – sensory to the face Name & Location of 1 o Nuclei – l l Motor Sensory – – – Mesencephalic Nucleus: proprioception Pontine Trigeminal Nucleus: touch Nucleus of Spinal Tract (spinal trigeminal tract): pain & temp

Cranial Nerves CN V – Trigeminal Nerve l – Testing: l l l – Sharp & light touch over the three divisions Corneal Blink Reflex (sensory) Clinch teeth & Jaw Jerk Signs of Dysfunction: l l l Weakness Hemianesthesia Absent Corneal Blink Reflex

Cranial Nerves CN VI – Abducens Nerve l – – – Function: somatic motor Name & Location of 1 o Nuclei Testing: l – Six Cardinal Fields of Gaze Signs of Dysfunction: l l Horizontal diplopia Medial deviation of the eye

Cranial Nerves CN VII – Facial Nerve l – Function: Branchial motor – facial muscles l Visceral motor – glandular fcn l General Sensory – skin of the auricle l Special Sensory - taste Name & Location of 1 o Nuclei: l Facial Motor Nucleus l Superior Salivatory Nucleus l Nucleus of Spinal Tract l Nucleus Solitarius l –

Cranial Nerves CN VII – Facial Nerve l – Testing: l l – Branchial motor component: facial expression Special Sensory: taste to the anterior 2/3 of tongue Signs of Dysfunction: l l l Hemiparesis Dry eye Lagophthalmos Dry mouth Loss of taste

Cranial Nerves CN VIII – Acoustic (Vestibulocochlear) Nerve l – – Function: special sensory Name & Location of 1 o Nuclei: l l – – Vestibular Nucleus Dorsal & Ventral Cochlear Nucleus Testing: hearing tests: Rinne, Weber, Audiology Signs of Dysfunction: l l Vertigo Nystagmus Disequilibrium Sensorineural deafness

Cranial Nerves CN IX – Glossopharyngeal Nerve l – Function: l l l Branchial Motor – elevation of pharynx during swallowing & speech Visceral Motor – parotid gland fcn Visceral Sensory – communication between carotid body & sinus General Sensory - tongue Special Sensory - taste

Cranial Nerves CN IX – Glossopharyngeal Nerve l – Name & Location of 1 o Nuclei: l l l – Nucleus Ambiguous Inferior Salivatory Nucleus Solitarius Nucleus of Spinal Tract Nucleus Solitarius Testing: l l l Branchial Motor: swallowing General Sensory: gag reflex Special sensory: taste of posterior 1/3 of tongue

Cranial Nerves CN IX – Glossopharyngeal Nerve l – Signs of Dysfunction l l l Dysphagia Dry mouth Loss of taste Loss of gag reflex TYPICALLY, IX and X are tested together

Cranial Nerves CN X – Vagus Nerve l – Function: l l Branchial Motor – deglutition & phonation Visceral Motor – smooth muscles of the thoracic & abdominal viscera Visceral Sensory – thoracic & abdominal viscera General Sensory – external ear TYPICALLY, IX and X are tested together

Cranial Nerves CN X – Vagus Nerve l – Name & Location of 1 o Nuclei: l l – Testing: l – Nucleus Ambiguous Dorsal Vagal Nucleus Solitarius Nucleus of Spinal Tract Branchial motor: swallowing, gag reflex, soft palate elevation with uvula remaining while saying “Ah” Signs of Dysfunction: l l l Dyspagia Hoarsness Uvula deviation

Cranial Nerves CN XI – Spinal Accessory Nerve l – – Function: somatic motor Name & Location of 1 o Nuclei Testing: Resisted shoulder elevation & head rotation Signs of Dysfunction: l l l Atrophy & Weakness Fasciculations Neck or shoulder deviation

Cranial Nerves CN XII – Hypoglossal Nerve l – – – Function: somatic motor Name & Location of 1 o Nuclei Testing: l l l – Stick out tongue Press tongue against check while palpating to test muscle strength Articulation of hard consonants: ‘L’, ‘T’, ‘D’, & ‘N’ Signs of Dysfunction: l l l Atrophy & Weakness Deviation Dysarthria