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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.
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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 • 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 • CN I – Olfactory Nerve • Function: special sensory • Name & Location of 1o Nuclei: cribriform plate • Testing: • 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 • CN II – Optic Nerve • Function: special sensory • Name & Location of 1o Nuclei: retina • Testing: • Snellen Eye chart • Fundus Exam • Visual fields via confrontation • Pupillary Light reflex • Signs of Dysfunction • Blindness • Loss of pupillary constriction (sensory)
Cranial Nerves • CN III – Occulomotor Nerve • Function: somatic & visceral motor • Name & Location of 1o Nuclei: • Somatic Motor Nucleus: EOM • Visceral Motor: pupillary constriction & accommodation • Testing: • Six Cardinal Fields of Gaze • Pupillary Light reflex: (motor) • Accommodation • Signs of Dysfunction: • Eye turned down & out w/ ptosis • Mydriasis, Loss of accommodation, Diplopia
Cranial Nerves • CN IV – Trochlear Nerve • Function: somatic motor • Name & Location of 1o Nuclei • Testing: • Six Cardinal Fields of Gaze • Signs of Dysfunction: • Vertical diplopia • Excycodeviation of the eye
Cranial Nerves • CN V – Trigeminal Nerve • Function: • Branchial motor – mastication • General Sensory – sensory to the face • Name & Location of 1o Nuclei – • Motor • Sensory • Mesencephalic Nucleus: proprioception • Pontine Trigeminal Nucleus: touch • Nucleus of Spinal Tract (spinal trigeminal tract): pain & temp
Cranial Nerves • CN V – Trigeminal Nerve • Testing: • Sharp & light touch over the three divisions • Corneal Blink Reflex (sensory) • Clinch teeth & Jaw Jerk • Signs of Dysfunction: • Weakness • Hemianesthesia • Absent Corneal Blink Reflex
Cranial Nerves • CN VI – Abducens Nerve • Function: somatic motor • Name & Location of 1o Nuclei • Testing: • Six Cardinal Fields of Gaze • Signs of Dysfunction: • Horizontal diplopia • Medial deviation of the eye
Cranial Nerves • CN VII – Facial Nerve • Function: • Branchial motor – facial muscles • Visceral motor – glandular fcn • General Sensory – skin of the auricle • Special Sensory - taste • Name & Location of 1o Nuclei: • Facial Motor Nucleus • Superior Salivatory Nucleus • Nucleus of Spinal Tract • Nucleus Solitarius
Cranial Nerves • CN VII – Facial Nerve • Testing: • Branchial motor component: facial expression • Special Sensory: taste to the anterior 2/3 of tongue • Signs of Dysfunction: • Hemiparesis • Dry eye • Lagophthalmos • Dry mouth • Loss of taste
Cranial Nerves • CN VIII – Acoustic (Vestibulocochlear) Nerve • Function: special sensory • Name & Location of 1o Nuclei: • Vestibular Nucleus • Dorsal & Ventral Cochlear Nucleus • Testing: hearing tests: Rinne, Weber, Audiology • Signs of Dysfunction: • Vertigo • Nystagmus • Disequilibrium • Sensorineural deafness
Cranial Nerves • CN IX – Glossopharyngeal Nerve • Function: • 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 • Name & Location of 1o Nuclei: • Nucleus Ambiguous • Inferior Salivatory Nucleus • Nucleus Solitarius • Nucleus of Spinal Tract • Nucleus Solitarius • Testing: • Branchial Motor: swallowing • General Sensory: gag reflex • Special sensory: taste of posterior 1/3 of tongue
Cranial Nerves • CN IX – Glossopharyngeal Nerve • Signs of Dysfunction • Dysphagia • Dry mouth • Loss of taste • Loss of gag reflex • TYPICALLY, IX and X are tested together
Cranial Nerves • CN X – Vagus Nerve • Function: • 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 • Name & Location of 1o Nuclei: • Nucleus Ambiguous • Dorsal Vagal Nucleus • Nucleus Solitarius • Nucleus of Spinal Tract • Testing: • Branchial motor: swallowing, gag reflex, soft palate elevation with uvula remaining while saying “Ah” • Signs of Dysfunction: • Dyspagia • Hoarsness • Uvula deviation
Cranial Nerves • CN XI – Spinal Accessory Nerve • Function: somatic motor • Name & Location of 1o Nuclei • Testing: Resisted shoulder elevation & head rotation • Signs of Dysfunction: • Atrophy & Weakness • Fasciculations • Neck or shoulder deviation
Cranial Nerves • CN XII – Hypoglossal Nerve • Function: somatic motor • Name & Location of 1o Nuclei • Testing: • Stick out tongue • Press tongue against check while palpating to test muscle strength • Articulation of hard consonants: ‘L’, ‘T’, ‘D’, & ‘N’ • Signs of Dysfunction: • Atrophy & Weakness • Deviation • Dysarthria