Causative factors and epidemiology of bilateral vestibulopathy in 255 patients

Abstract
Objective To determine the causative factors and epidemiology of bilateral vestibulopathy (BV). Methods This is a retrospective review of 255 patients (mean age, 62 ± 16 years) with BV diagnosed in our dizziness unit between 1988 and 2005. All patients had undergone a standardized neurophthalmological and neurootological examination, electronystagmography with caloric irrigation, cranial magnetic resonance imaging or computed tomography (n = 214), and laboratory tests. Results Sixty-two percent of the study population were male subjects. Previous vertigo attacks had occurred in 36%, indicating a sequential manifestation. The definite cause of BV was determined in 24% and the probable cause in 25%: The most common causes were ototoxic aminoglycosides (13%), Menière's disease (7%), and meningitis (5%). Strikingly, 25% exhibited cerebellar signs. Cerebellar dysfunction was associated with peripheral polyneuropathy in 32% compared with 18% in BV patients without cerebellar signs. Hypoacusis occurred bilaterally in 25% and unilaterally in 6% of all patients. It appeared most often in patients with BV caused by Cogan's syndrome, meningitis, or Menière's disease. Interpretation The cause of BV remains unclear in about half of all patients despite intensive examinations. A large subgroup of these patients have associated cerebellar dysfunction and peripheral polyneuropathy. This suggests a new syndrome that may be caused by neurodegenerative or autoimmune processes. Ann Neurol 2007