Vertical vestibulo-ocular reflex in patients with benign paroxysmal positional nystagmus

The vertical vestibulo-ocular reflex (VOR) was tested in 13 patients with benign paroxysmal positional nystagmus and in ten normal subjects. Patients and normal subjects were rotated in the sagittal plane and in the plane of the vertical semicircular canal pairs using sine and step stimuli. Gain, phase, and time-constant measurements of the vertical components of induced nystagmus were not significantly different (P greater than normal 0.05) in the normal subjects and patients for any test condition. At least for the range of test stimuli used in this study, the dynamics of the vertical VOR were normal in patients with benign paroxysmal positional nystagmus.