Benign Paroxysmal Positional Vertigo of the Horizontal Canal: A Form of Canalolithiasis with Variable Clinical Features

摘要: Benign paroxysmal positional vertigo of the horizontal semicircular canal (HC-BPPV) is a well-defined syndrome characterized by direction-changing nystagmus. We report clinical features 5 patients who illustrate possible variables syndrome. In most cases, nystagmus geotropic and more intense when pathological ear lowermost; less often presents with apogeotropic that affected uppermost. The pattern may vary in time same patient, changing from to even observations at short intervals. some patients, indicate involvement than one canal, either simultaneously or succession. It sustained findings can be explained movement endolymph caused displacement otoconia canals variants are due different positions within canals.