Central positional vertigo: A clinical-imaging study.

The diagnosis of central positional vertigo (CPV) is challenging, mainly because symptoms overlap with the common variants of benign paroxysmal positional vertigo (BPPV). Recent correlations of imaging with neurotologic exams have improved our understanding of CPV and ability differentiate it from BPPV. Yet, there is still a need to develop better diagnostic algorithms to improve timely diagnosis and early intervention. Here we present a retrospective review of the clinical characteristics, neurotologic evaluation and imaging of CPV in a cohort of 27 patients and propose a diagnostic algorithm to be tested in future prospective fashion. Most patients had positional nystagmus (downbeat and apogeotropic horizontal), cerebellar ocular motor abnormalities and truncal ataxia indicative of a central lesion. 61.5% of our cohort had paroxysmal CPV, 30.5% had a non-paroxysmal CPV and 8% paroxysmal-evolving-to-non-paroxysmal CPV. The most common pattern of positional nystagmus evoked with maneuvers was positional downbeat nystagmus (pDBN, 69.2%), apogeotropic horizontal nystagmus (42.3%), geotropic (7.69%) and multiplanar (23.0%). Notably, 13 (50%) of patients had cerebral imaging prior to CPV being on the differential diagnosis, whereas another 50% of patients had CPV diagnosis preceding their work-up. Unilateral lesions on imaging were 4× less likely to exhibit nausea and vomiting, nearly 2× less likely to exhibit paroxysmal nystagmus, and 2× less likely to exhibit nystagmus with habituality. Findings of pDBN or apogeotropic nystagmus alone were enough to diagnose CPV in 50% of our patient cohort, underscoring the importance of clinical evaluation in a time when an "imaging-first" philosophy is gaining popularity in Neurology.
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