0071643192.pdf

CRANIAL NERVE DISORDERS

Trigeminal Neuralgia

The trigeminal nerve (CN V) has three anatomic divisions, V 1 -ophthalmic, V 2 -

maxillary, and V 3 -mandibular, which innervate the cornea, the face, and the

mucous membranes of the oral and nasal cavity. The motor fibers innervate

the muscles of mastication.

SYMPTOMS/EXAM

■ Brief, recurrent episodes of excruciating, unilateral facial pain

■ Right > left side predominance

■ May be able to elicit pain by tapping the side of the face, otherwise there

should be no demonstrable physical findings

DIFFERENTIAL

■ Includes vascular or space-occupying lesions (acoustic neuroma), demyeli-

nating diseases (multiple sclerosis), herpes zoster, sinus infection, odonto-

genic pathology, migraine, temporomandibular joint dysfunction

DIAGNOSIS

■ Based on clinical presentation

■ Imaging should be performed to rule out other etiologies if neurological

findings are present.

NEUROLOGY

TABLE 15.12. Disorders Causing Peripheral Vertigo

DISORDER PATHOPHYSIOLOGY ASSOCIATED FINDINGS

Benign paroxysmal positional Otoconia in the semicircular canals Precipitated by sudden head movement

vertigo (BPPV) Positive Dix-Hallpike

Improvement/resolution with Epley maneuver

Meniere disease Increased endolymph within the Ear “fullness,” tinnitus, hearing loss

cochlea and labyrinth

Labyrinthitis Viral or bacterialinfection Middle-ear findings (infection, fluid), tinnitus,

hearing loss

Vestibular neuronitis Viral infection Lasts several days, no recurrence or hearing loss

Ramsay-Hunt syndrome Viral infection of vestibular gangion Hearing loss, vertigo, facial nerve palsy, grouped

(vestibular ganglionitis) vesicles

Perilymph fistula Trauma, sudden pressure change Abrupt onset after inciting event +/−hearing loss

Requires surgical repair

Ototoxicity Damage to vestibular apparatus Hearing loss, vertigo, tinnitus

—may be irreversible

CN VIII lesions Schwannomas, meningioma Gradual onset, preceded by hearing loss

Treatment for trigeminal

neuralgia = Tegretol

(carbamazepine)