FACTS & HINTS

High-Yield Facts

Clinical Points

Facial Nerve Palsy

Unilateral (one-sided) injuryto the facial nerve or its branches

Results in sudden weakness affecting some or all of facial muscles on affected side

Causes include: infections such as TB, polio; brainstem lesions; tumors, such as acoustic neuromas; acute and sudden exposure of the face to cold temperatures

Angle of mouth droops on affected side with dribbling of food and saliva Sad look when face is relaxed

Lower eyelid falls awayfrom eyeball with drying of cornea and tearing from corner of eye Speech affected (production of B,M,P, and Wsounds), because of weakened lip muscles

Trigeminal Neuralgia

Disease affecting the sensoryroot of CN V

Characterized byepisodes of intense pain lasting a few seconds in areas innervated bythe trigeminal nerve.

Usuallyone-sided and can affect a division of CN V, usuallythe mandibular, maxillarynerve.

Pain can be triggered bytouching a sensitive area ("trigger point")

The cause is not usuallyknown

Treatment is directed to controlling the pain.

Ocular Nerve Palsy

Alesion of the oculomotor nerve will paralyze all extraocular muscles except the lateral rectus and the superior oblique. This leads to : Ptosis-drooping of the eyelid (levator palpebrae superioris)

No constriction of the pupil in response to light (sphincter pupillae) Dilation of the pupil (unopposed dilator pupillae)

Eyeball abducted and depressed ("down and out") (unopposed lateral rectus and superior oblique) No accommodation of the lens for near vision (ciliarymuscle)

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Mnemonics

Memory Aid

Names of the Cranial Nerves

"On Old Olympus Towering Tops AFew Virile Germans Viewed Ample Of Hops"

Memory Aid

Motor, Sensory and Mixed (Both) Cranial Nerves

"Some SayMarryMoneyBut MyBrother Says Bad Business MarryMoney"

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