Differentiating central from peripheral origins of vestibulo-ocular reflex (VOR) lesions can be challenging. A 36-year old man presented with a 1-year history of progressive unsteadiness. The video-Head Impulse Test revealed a significantly reduced VOR gain in both horizontal and posterior canals (0.49 ± 0.05 and 0.38 ± 0.06) but normal VOR responses in both anterior canals (0.89 ± 0.08 and 1.04 ± 0.15). No plausible combination of end-organ lesion should be responsible for these observations. A brain magnetic resonance imaging disclosed a left inferior cerebellar peduncle lesion suggestive of a glioma.

The apogeotropic variant of horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV) is attributed to canalithiasis of the anterior arm or cupulolithiasis. Despite some therapeutic maneuvers, I propose a new treatment strategy for apogeotropic HC-BPPV that is designed to detach both the otoconial debris from the anterior arm of the semicircular canal and the debris that is attached to the utricular side of the cupula using inertia and gravity and based on simulations with a 3D biomechanical model.

The apogeotropic variant of horizontal semicircular canal benign paroxysmal positional vertigo (HC-BPPV) is attributed to free floating particles in the anterior arm of the lateral semicircular canal – particles attached to the cupula facing the canal or particles attached to the cupula facing the utricle. Zuma e Maia described a new treatment for both canalithiasis of the anterior arm of the horizontal semicircular canal (HC) and cupulolithiasis of the HC. Seventeen patients with apogeotropic HC-BPPV were enrolled and treated with Zuma’s Maneuver. During the repositioning of the particles to the utricule, we observed the direction of the nystagmus evoked in each step of this maneuver in order to know where the otoliths were probably located. Eight patients were diagnosed with canalithiasis of the anterior arm, six patients with cupulolithiasis with the particles facing the canal and three patients with cupulolithiasis with the particles facing the utricle. Our data suggest that we can assume where the otoliths are probably located by observing the pattern of the nystagmus evoked in each step of the Zuma’s Maneuver in patients with apogeotropic HC-BPPV.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vestibular vertigo. It is caused by free-floating otoconia moving freely in one of the semicircular canals (canalolithiasis) or by otoliths adhered to the cupula (cupulolithiasis). The posterior canal is the most common canal affected, followed by the lateral canal. Diagnosis of the side affected is critical for successful treatment; therefore, suppressing visual fixation is essential to examination of these patients' eye movement. On the basis of our experience, we have adopted the Zuma maneuver and the modified Zuma maneuver for both apogeotropic and geotropic variants of lateral canal BPPV. Knowledge of the anatomy and pathophysiologic mechanisms of the semicircular canals is essential for correct management of these patients. Hence, using a single maneuver and its modification may facilitate daily neurotological practice.

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