Vertical nystagmus during the seated–supine positional (straight head-hanging) test in patients with benign paroxysmal positional vertigo
AbstractObjective:This study describes the clinical features of up-beating vertical nystagmus observed during the seated–supine positional (straight head-hanging) test in patients with benign paroxysmal positional vertigo.Methods:A total of 190 patients with benign paroxysmal positional vertigo symptoms who had presented between 2009 and 2012 were enrolled for this retrospective case series. Twelve patients with positional up-beating vertical nystagmus, as confirmed by video-nystagmography during the seated–supine positional test, were selected.Results:The incidence and duration of symptoms of multiple canal benign paroxysmal positional vertigo were significantly lower compared with the other types of benign paroxysmal positional vertigo (p = 0.029 and p = 0.048 respectively). Trauma was the leading aetiological factor in those patients (p = 0.012). The average number of therapeutic manoeuvres required for the relief of symptoms in patients with multiple canal involvement was significantly higher than in the other groups (p = 0.041).Conclusion:In patients with benign paroxysmal positional vertigo, the presence of vertical up-beating nystagmus while lying down is a unique peripheral sign and could indicate multiple canal involvement. Therefore, the seated–supine positional test should always be included in the test battery.