Significance of Spontaneous Vertical Nystagmus: A Pilot Study of 30 Cases in a Tertiary Care Vestibular Clinic

Vertical nystagmus, often deemed a hallmark of central pathology, poses a diagnostic challenge in vestibular clinics. This retrospective study, examining 30 patients over six months, aims to gain insight into the clinical features, underlying causes, and diagnostic relevance of spontaneous vertical nystagmus. Among the 94 patients assessed at a tertiary vertigo clinic, 30 showed vertical spontaneous nystagmus. Vestibular migraine was the most common diagnosis (53.33%), followed by vertical canal BPPV (33.33%). Notably, 87.5% of migraine cases exhibited solely vertical nystagmus, whereas BPPV cases had a mixed component. Positional testing, high-frequency head shake test, hyperventilation, and SVV deviations all showed potential triggers and diagnostic indicators. This study highlights that vertical nystagmus is not exclusively indicative of central pathology. It emphasizes the importance of conducting a comprehensive vestibular evaluation—including provocative positional testing, subjective visual vertical (SVV) assessment, and detailed clinical interpretation—to accurately differentiate between central and peripheral causes of nystagmus.