cranial nerves

CN I — Olfactory

Type: Sensory

Function: Smell

Assessment: Close 1 nostril and identify familiar scents.

CN II - Optic

Type: sensory

Function: vision

Assessment: visual field (look at bridge of examiners nose and indicate when object in periphery is seen) and visual field (Suellen chart)

CN III - oculomotor

Type: Motor

Function: Eye movement (up, down, medial), eyelid opening, pupil constriction.

Assessment: (including IV and VI) - move finger in 6 directions; check PERRLA.

CN IV - Trochlear

Type: Motor

Function: Eye movement (down and inward)

Assessment: (Same as III and VI) - Six cardinal positions of gaze, PERRLA.

CN V - Trigeminal

Type: Both

Function: Facial sensation, corneal reflex, chewing.

Assessment: Close eyes; identify touch and pinprick on face. Clench teeth — assess strength.

CN VI - Abducens

Type: Motor

Function: Lateral eye movement.

Assessment: (Same as III and IV) - Six cardinal positions of gaze, PERRLA.

CN VII - Facial

Type: Both

Function: Facial expression, taste (anterior 2/3 tongue), eyelid closing, saliva/tear production.

Assessment: Raise eyebrows, close eyes tightly, purse lips, smile, frown, taste test (sweet vs salty).

CN VIII - Vestibulocochlear

Type: Sensory

Function: Hearing and balance

Assessment: Close eyes and indicate when hearing rustling of examiners fingertips.

CN IX - Glossopharyngeal

Type: Both

Function: Taste (posterior 1/3 tongue), gag reflex, swallowing

Assessment: Elicit gag reflex

CN X - Vagus

Type: Both

Function: Parasympathetic control (heart, lungs, digestion), gag reflex

Assessment: Elicit gag reflex

CN XI - Accessory

Type: Motor

Function: Shoulder shrug and head rotation

Assessment: Shrug shoulders and turn head side-to-side against resistance

CN XII - Hypoglossal

Type: Motor

Function: Tongue movement

Assessment: Stick out tongue, push tongue side to side against resistance from tongue blade.