Vertical nystagmus during the seated-supine positional (straight head-hanging) test in patients with benign...

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.

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.

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).

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.