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CRANIAL NERVE DEFECTS
Olfactory CN I
Optic CN II
S*
S*
Forebrain
Forebrain
Trauma
Anosmia
Pre-chiasm
Unilateral Blindness
Chiasm
Bitemporal Hemianopia
Post Chiasm
Homonymous hemianopsia
Infective/AI
Optic Neuritis
Loss of ability to smell
Ocularmotor CN III
M*
Midbrain
Ocular Motor Palsy
Affected eye pulled down and out
Trochlea CN IV
M*
Midbrain
Trochlea Palsy
Affected eye unable to look down
Trigeminal CN V
B*
Pons
Abducens CN VI
M*
Pons
Abducens Palsy
Facial CN VII
B*
Pons
Facial Nerve Palsy
Vestibulocochlea CN VIII
S*
Pons
Vestibulocochlea
Lesion
Glossopharyngeal CN IX
B*
Medulla
Lesion
Loss of taste to posterior 1/3 of tongue
Vegas CN X
B*
Medulla
Lesion
Loss of gag reflex, dysphagia of fluids and solids
Accessory CN XI
M*
Medulla
Lesion
Reduced Muscular activity of Sternocleidomastoid and Trapezius
Hypoglossal CN XII
M*
Medulla
Lesion
Slurred speech, Tongue deviates the way of the lesion
* S=sensory, M=motor, B=both
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Trigeminal Neuralgia
Unilateral pain can be a single branch or all three
Trigeminal Palsy
Weakness of chewing muscles
Affected eye unable to look laterally
UMNL
Forehead Spared
LMNL
Forehead Involved
Sensory Deafness
Weber’s and Rinne’s test
Dizziness
Eyes closed one foot
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Facial Nerve Palsy - Bell's palsy
Bulbar Palsy – Affects CN V, VII, IX, X, XI
Pseudobulbar palsy – is an UMNL which causes similar effects to Bulbar Palsy
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