1. 5 The Cranial Nerves 8 8 Clinical Assessment3 3 8 8 2 2
Clinical Assessment 6 1 6 4 4 9 10 12
The “FACE” of Cranial Nerves
J Carley MSN, MA, CNE
Fall 2009

2. 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

3. Cranial Nerves
When assessing the cranial nerves, there are 3 items the examiner must know:
Function (Motor, Sensory, Mixed)
Testing
Signs of Dysfunction

4. Cranial Nerves CN I – Olfactory Nerve Function: special sensory
O O O T T A F A G V S H
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

5. Cranial Nerves CN II – Optic Nerve Function: special sensory Testing:
O O O T T A F A G V S H
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)

6. Cranial Nerves CN III – Occulomotor Nerve
O O O T T A F A G V S H
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

7. Cranial Nerves CN IV – Trochlear Nerve Function: somatic motor
O O O T T A F A G V S H
CN IV – Trochlear Nerve
Function: somatic motor
Testing:
Six Cardinal Fields of Gaze
Signs of Dysfunction:
Vertical diplopia
Excycodeviation of the eye

8. Cranial Nerves CN V – Trigeminal Nerve Function:
O O O T T A F A G V S H
CN V – Trigeminal Nerve
Function:
Branchial motor – mastication
General Sensory – sensory to the face

9. Cranial Nerves CN V – Trigeminal Nerve Testing: Signs of Dysfunction:
O O O T T A F A G V S H
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

10. Cranial Nerves CN VI – Abducens Nerve Function: somatic motor Testing:
O O O T T A F A G V S H
CN VI – Abducens Nerve
Function: somatic motor
Testing:
Six Cardinal Fields of Gaze
Signs of Dysfunction:
Horizontal diplopia
Medial deviation of the eye

11. Cranial Nerves CN VII – Facial Nerve Function:
O O O T T A F A G V S H
CN VII – Facial Nerve
Function:
Branchial motor – facial muscles
Visceral motor – glandular fcn
General Sensory – skin of the auricle
Special Sensory - taste

12. Cranial Nerves CN VII – Facial Nerve Testing: Signs of Dysfunction:
O O O T T A F A G V S H
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

13. Cranial Nerves CN VIII – Acoustic (Vestibulocochlear) Nerve
O O O T T A F A G V S H
CN VIII – Acoustic (Vestibulocochlear) Nerve
Function: special sensory
Testing: hearing tests: Rinne, Weber, Audiology, whisper, fingertips
Signs of Dysfunction:
Vertigo
Nystagmus
Disequilibrium
Sensorineural deafness

14. Cranial Nerves CN IX – Glossopharyngeal Nerve Function:
O O O T T A F A G V S H
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

15. Cranial Nerves CN IX – Glossopharyngeal Nerve Testing:
O O O T T A F A G V S H
CN IX – Glossopharyngeal Nerve
Testing:
Branchial Motor: swallowing
General Sensory: gag reflex
Special sensory: taste of posterior 1/3 of tongue

16. Cranial Nerves TYPICALLY, IX and X are tested together
O O O T T A F A G V S H
CN IX – Glossopharyngeal Nerve
Signs of Dysfunction
Dysphagia
Dry mouth
Loss of taste
Loss of gag reflex
TYPICALLY, IX and X are tested together

17. Cranial Nerves TYPICALLY, IX and X are tested together
O O O T T A F A G V S H
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

18. Cranial Nerves CN X – Vagus Nerve Testing: Signs of Dysfunction:
O O O T T A F A G V S H
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

19. Cranial Nerves CN XI – Spinal Accessory Nerve Function: somatic motor
O O O T T A F A G V S H
CN XI – Spinal Accessory Nerve
Function: somatic motor
Testing: Resisted shoulder elevation & head rotation
Signs of Dysfunction:
Atrophy & Weakness
Fasciculations
Neck or shoulder deviation

20. Cranial Nerves CN XII – Hypoglossal Nerve Function: somatic motor
O O O T T A F A G V S H
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