Authors: Corinna Lechner Rachael L Taylor Chris Todd Hamish MacDougall Robbie Yavor G Michael Halmagyi Miriam S Welgampola
Publish Date: 2014/03/28
Volume: 261, Issue: 5, Pages: 1009-1017
Abstract
Direction changing horizontal positional nystagmus can be observed in a variety of central and peripheral vestibular disorders We tested sixty subjects with horizontal positional nystagmus and vertigo on the Epley Omniax® rotator Monocular video recordings were performed with the right or left ear down in the supine and prone positions Nystagmus slowphase velocity SPV was plotted as a function of time Thirtyone subjects diagnosed with horizontal canalolithiasis had paroxysmal horizontal geotropic nystagmus with the affected ear down onset 08 ± 1 s range 0–49 s duration 117–479 s peak SPV 79 ± 67°/s The SPV peaked at 5–20 s and declined to 0 by 60 s at 40 s from onset the average SPV was 18 of the peak Nine subjects diagnosed with cupulolithiasis had persistent apogeotropic horizontal nystagmus onset 07 ± 14 s range 0–43 s Peak SPV was 542 ± 318°/s and 266 ± 122°/s with unaffected and affected ears down respectively At 40 s the average SPV had decayed to only 81 unaffected ear down and 65 affected ear down of the peak Twenty subjects were diagnosed with disorders other than benign positional vertigo BPV vestibular migraine VM Ménière’s Disease vestibular schwannoma unilateral or bilateral peripheral vestibular loss Subjects with VM n = 13 had persistent geotropic or apogeotropic horizontal nystagmus On average at 40 s from nystagmus onset the SPV was 61 of the peak Two patients with Ménière’s Disease had persistent apogeotropic horizontal nystagmus the peak SPV at 40 s ranged between 286 and 495 of the peak Symptomatic horizontal positional nystagmus can be observed in canalolithiasis cupulolithiasis and diverse central and peripheral vestibulopathies its temporal and intensity profile could be helpful in the separation of these entities
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