Abstract
Conclusions: The nystagmus recorded without visual fixation contained all three components in most patients with vestibular neuritis (VN). The nystagmus was unidirectional, strongly visually suppressed with the loss of vertical component in most patients, and it obeyed Alexander's law. Video-oculography (VOG) is a non-invasive tool for detailed analysis of nystagmus, and hence may improve differential diagnostics in dizzy patients. Objective: To characterize three-dimensional nystagmus findings in patients with acute VN using the VOG technique. Patients and methods: A prospective study in 16 patients with VN was carried out in a tertiary referral centre. Nystagmus was measured on average 3 days after the beginning of symptoms. Subjective assessment of dizziness and quality of life was performed. The slow phase velocity, frequency, visual suppression and gaze position dependency of nystagmus were analysed. Results: The mean slow phase velocity without visual fixation was 7.7±2.3°/s in horizontal, 3.4±1.6°/s in vertical, and 3.5±1.6°/s in torsional plane, and it decreased significantly with visual fixation to 1.5±1.0°/s (p<0.000), 0.2±0.4°/s (p=0.001), 1.6±1.2°/s (p=0.004), respectively. The nystagmus was unidirectional, and horizontal gaze shifts enhanced or suppressed it on average 1.5°/s per 10°. Quality of life score of 3.7±0.7 improved significantly (p=0.002) to 1.5±0.5 during the follow-up period.