ABSTRACT
PURPOSE: To investigate the prevalence of reversal nystagmus in individuals with benign paroxysmal positional vertigo (BPPV). STUDY DESIGN: Prevalence of reversal nystagmus was assessed in 28 subjects with unilateral posterior canal BPPV, canalithiasis type. Six trials of Dix-Hallpike testing were completed for each subject. RESULTS: Reversal nystagmus was present in 129 out of 167 Dix-Hallpike maneuvers that were performed (77.2%). In 19 trials where nystagmus was absent with the dependent position of Dix-Hallpike testing, reversal nystagmus was nonetheless demonstrated in 11 trials (57.9%). CONCLUSION: Reversal nystagmus is commonly demonstrated in individuals with posterior canal BPPV, canalithiasis type. It is frequently evoked even when there is no nystagmus with the dependent position of Dix-Hallpike testing. Observation of reversal nystagmus may enhance the identification of BPPV during Dix-Hallpike testing.
