Cranial Nerve

Question 1

Olfactory I
(function/test/abnormal findings)

Answer 1

Funtion: smell
Test: sense of smell each side, use nonirritating odors
Abnormal: Anosmia (inability to detect smells)- seen with frontal lobe lesions

Question 2

Optic II
(function/test/abnormal findings)

Answer 2

Function: vision, pupillary reflex (afferent= sensory)
Test: Test visual acuity, Central (snellen test), Peripheral (visual fields)
Abnormal: Blindness, myopia (impaired far vision), presbyopia (impaired near vision). Visual field defects: homonymous hemianopsia

Question 3

Oculomotor III
(function/test/abnormal findings)

Answer 3

Function: Pupillary reflex (efferent= motor), Accomodation Convergence
Test: Shine light into pupil
Abnormal: Absense of pupillary reflex (absence of pupillary relfex on both eyes = CN II injury, absent in tested eye indicates CN III), lateral strabismus

Question 4

Oculomotor III,Trochlear IV, Abducenc VI
(function/test/abnormal findings)

Answer 4

Function:
- CN III: Turns eyes up, down, in
- CN IV: Turns adducted eye down
- CN VI: Turns eye out
Test: Ask pt to look up, down, medial and laterally
Abnormal:
- Lateral Stabismus: eyeball turns lateral
- CN III lesion can lead to ptosis
- Inability to look down and in
- Medial strabisums: eyeball turns medially (inward) can cause diplopia

Question 5

Trigeminal V
(function/test/abnormal findings)

Answer 5

Function: Sensory= face, cornea
motor= temoral and massater muscles
Test: test pain, light touch and sensation on forehead, cheeks and jaw
Abnormal: loss of facial sensation, weakness: muscle wasting of muscles of mastication, Assymetry of jaw movement

Question 6

Facial VII
(function/test/abnormal findings)

Answer 6

Function: facial expression
Sensory= tast to 2/3 of anterior tongue
Test: Motor function of facial muscle= raise eye brows, frown, puff up cheeks,smile. Tongue: Apply sweet, salty and sour solutions to lateral aspect of tongue
Abnormal: Paralysis ipsilateral facial muscles, inability to close eye, difficulty with speech articulation, decrease taste

Question 7

Vestibulocochlear VIII
(function/test/abnormal findings)

Answer 7

Function: Vestibular function (acustic), VOR
Test: balance, vestibulospinal function, VOR, auditory acuity
Abnormal: Vertigo, dysequilibrium, Gaze instability with head movement,, nystagmys (an involuntary, rapid, rhythmic oscillatory eye movement), deafness

Question 8

Glossopharyngeal IX
(function/test/abnormal findings)

Answer 8

Function: Sensory= post 1/3 of tongue, pharynx
Test: Apply sour, sweet, salty solution to tongue
Abnormal: abnormal tast

Question 9

Glossopharyngeal IX and Vagus X
(function/test/abnormal findings)

Answer 9

Function: phonation, swallowing
Test: listlen to voice quality
Abnormal: Dysphonia: hoarseness denotes in vocals, vocal cord paralysis/ Dysphagia: difficulty swallowing or loss of sawllogn reflex

Question 10

Glossopharyngeal IX and Vagus X
(function/test/abnormal findings)

Answer 10

Function: Gag reflex, pharynx control
Test: Say “ah”, stimulate uvula
Abnormal: Dysarthria: difficulty articulating words clearly, slurred. Paralysis: palate fails to elevate

Question 11

Accessory XI
(function/test/abnormal findings)

Answer 11

Function: Trap movement, SCM
Test: inability to elevate shoulder girdle or put shoulder to ear
Abnormal: Atrophy or weakness

Question 12

Hypoglossal XII
(function/test/abnormal findings)

Answer 12

Function: Tongue movement
Test: examine resting position of tongue
Abnormal: Dysarthria (lesion of X and XII)