Vertigo

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Vertigo is a false sense of movement resulting from dysfunction of the vestibular system. Vertigo can become severely disabling by rendering patients unable to walk or even open their eyes secondary to imbalance and nausea. Whether central or peripheral in origin, vertigo can be compensated unless sudden or intermittent. Surgical intervention is most likely to be effective with these types of lesions, especially when originating from labyrinthine dysfunction.

Causes of Vertigo

Central vestibular disorders usually present with mild yet chronic vertigo and other neurologic deficits. Possible etiologies include vertebrobasilar ischemia, posterior fossa tumor, atypical migraine, Chiari malformation, Multiple Sclerosis, epileptic aura, and anti-Purkinje cell antibodies associated with some visceral tumors. In contrast to central vertigo, peripheral sources tend to present rapidly and briefly. They are benign in nature and may respond to neurosurgical intervention. Meniere’s Disease, or delayed endolymphatic hydrops, results from an imbalance of fluid compartments within the inner ear. Patients experience episodic vertigo, tinnitus, and hearing loss with superimposed, gradual decline of the latter faculty. Advanced disease may be complicated by drop attacks from loss of limb extensor tone. Meniere’s is classically idiopathic, though may develop following inner ear trauma or chronic otitis media. Benign Paroxysmal Positional Vertigo (BPPV) is believed to result from otoconia that have broken off the macula and entered into one of the semicircular canals. Certain head positions alter the center of gravity within the affected ear and lead to nystagmus and vertigo several seconds later. Infectious or vasculitic inflammation of the vestibular nerve or labyrinth can also cause vertigo, and in the latter structure sensorineural hearing loss as well.

Therapy

Central vestibular disorders may have treatable underlying pathologies such as tumor or ischemia. In peripheral disorders, intervention is directed at the vestibular organ itself. When an exact diagnosis is lacking, labyrinthectomy or vestibular nerve section may be indicated so long as the lesion is localized to one ear. Intractable BPPV may be specifically treated by singular inferior vestibular neurectomy of the branch innervating the posterior semicircular canal. Meniere’s patients may respond to endolymphatic sac procedures, although this treatment is controversial. Perilymphatic fistulas are difficult to diagnose but should be suspected in patients with trauma or surgery to the ear. On inspection, defects within the bony labyrinth may be repaired by removing the mucosa and overlaying a connective tissue patch.

References

1. Baloh RW, Honrubia V: Clinical Neurophysiology of the Vestibular System, 2nd ed. Philadelphia, FA Davis, 1990

2. Blakely BW: Clinical forum: A Review of Intratympanic Therapy. Am J Otol 18: 520-526, 1997

3. Green RE: Surgical Treatment of Vertigo with Follow Up on Walter Dandy’s cases. In Proceedings of the Congress of Neurological Surgeons. Baltimore, Wilkins and Williams, 1958, pp141-152

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