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[Clinical features of horizontal semicircular canal benign paroxysmal positional vertigo].

OBJECTIVE
To explore the clinical features of horizontal semicircular canal benign paroxysmal positional vertigo.


METHODS
The clinical manifestations of 239 patients with horizontal semicircular canal benign paroxysmal positional vertigo from August 2003 to December 2010 were retrospectively analyzed.


RESULTS
25.7% (239/931) of all the benign paroxysmal positional vertigo patients were the horizontal semicircular canal benign paroxysmal positional vertigo was involved. One hundred and ninety-seven patients showed geotropic nystagmus in head rolling test with a mean latency period of (0.88 ± 0.72) s and a mean duration period of (26.36 ± 19.71) s. Forty-two patients showed apogeotropic nystagmus in head rolling test with a mean latency period of (2.69 ± 1.83) s and a mean duration period of (53.48 ± 43.12) s. Among all the horizontal semicircular canal benign paroxysmal positional vertigo patients, 39 (16.3%) presented horizontal nystagmus with slight upbeating component. The nystagmus latency in apogeotropic nystagmus group was longer than that in geotropic nystagmus group (t = -6.33, P < 0.001), and nystagmus duration period was also longer (t = -3.99, P < 0.001). Applied Barbecue maneuver to the patients with geotropic nystagmus, 192 patients were cured after (1.6 ± 0.8) rotations; After applied head shaking maneuver to the patients with apogeotropic nystagmus, 40 patients changed to geotropic nystagmus and cured after (1.9 ± 0.8) rotations.


CONCLUSIONS
Incidence rate of horizontal semicircular canal benign paroxysmal positional vertigo was higher than expectation. Barbecue maneuver was applied to patients with geotropic nystagmus. While to the patients with apogeotropic nystagmus, head shaking maneuver should be performed firstly and then followed by Barbecue maneuver.