The Cranial Nerves Clinical Assessment The “FACE” of Cranial Nerves J Carley MSN, MA, CNE Fall 2009 1 2 2 3 3 4 4 5 6 6 8 8 9 10 12
The Cranial Nerves
Clinical Assessment
The “FACE” of Cranial Nerves
J Carley MSN, MA, CNEFall 2009
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I OlfactoryII OpticIII OculomotorIV TrochlearV Trigeminal
VI AbducensVII FacialVIII AcousticIX Glossopharyngeal
X VagusXI Spinal AccessoryXII Hypoglossal
Cranial Nerves
Cranial NervesWhen assessing the cranial nerves, there are
3 items the examiner must know:
Function (Motor, Sensory, Mixed)TestingSigns of Dysfunction
Cranial Nerves
CN I – Olfactory Nerve Function: special sensory
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
O O O T T A F A G V S H
Cranial Nerves CN II – Optic Nerve
Function: special sensory
Testing: Snellen Eye chart Fundus Exam Visual fields via confrontation Pupillary Light reflex
Signs of Dysfunction Blindness Loss of pupillary constriction (sensory)
O O O T T A F A G V S H
Cranial Nerves
CN III – Occulomotor Nerve Function: somatic & visceral motor
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
O O O T T A F A G V S H
Cranial Nerves CN IV – Trochlear Nerve
Function: somatic motor
Testing: Six Cardinal Fields of Gaze
Signs of Dysfunction: Vertical diplopia Excycodeviation of the eye
O O O T T A F A G V S H
Cranial Nerves
CN V – Trigeminal Nerve Function:
Branchial motor – mastication General Sensory – sensory to the face
O O O T T A F A G V S H
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
O O O T T A F A G V S H
Cranial Nerves
CN VI – Abducens Nerve Function: somatic motor Testing:
Six Cardinal Fields of Gaze Signs of Dysfunction:
Horizontal diplopia Medial deviation of the eye
O O O T T A F A G V S H
Cranial Nerves
CN VII – Facial Nerve Function:
Branchial motor – facial muscles Visceral motor – glandular fcn General Sensory – skin of the auricle Special Sensory - taste
O O O T T A F A G V S H
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
O O O T T A F A G V S H
Cranial Nerves
CN VIII – Acoustic (Vestibulocochlear) Nerve
Function: special sensory Testing: hearing tests: Rinne, Weber, Audiology,
whisper, fingertips Signs of Dysfunction:
Vertigo Nystagmus Disequilibrium Sensorineural deafness
O O O T T A F A G V S H
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
O O O T T A F A G V S H
Cranial Nerves
CN IX – Glossopharyngeal Nerve
Testing:
Branchial Motor: swallowing General Sensory: gag reflex Special sensory: taste of posterior 1/3 of tongue
O O O T T A F A G V S H
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
O O O T T A F A G V S H
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
O O O T T A F A G V S H
Cranial Nerves
CN X – Vagus Nerve Testing:
Branchial motor: swallowing, gag reflex, soft palate elevation with uvula remaining while saying “Ah”
Signs of Dysfunction: Dysphagia Hoarseness Uvula deviation
O O O T T A F A G V S H
Cranial Nerves
CN XI – Spinal Accessory Nerve Function: somatic motor Testing: Resisted shoulder elevation & head rotation Signs of Dysfunction:
Atrophy & Weakness Fasciculations Neck or shoulder deviation
O O O T T A F A G V S H
Cranial Nerves
CN XII – Hypoglossal Nerve Function: somatic motor 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
O O O T T A F A G V S H