The Presence of Nystagmus Suggests Geotropic Variant of Horizontal Semicircular Canal Benign Paroxysmal Positional Vertigo on the Left Side

The initial Dix-Hallpike test and supine roll test induced geotropic direction-changing horizontal nystagmus, which was more severe on the left side. Head-bending nystagmus (the head is bent 30° forward in the neutral sitting position) and lying-down nystagmus (the patient lies supine with the head flexed 30° forward) were not observed. Immediately after the initial positional test, a repeated right supine roll test was performed, which revealed right horizontal geotropic nystagmus with an amplitude similar to that seen during the left supine roll test. On a repeated head-bending nystagmus test, subtle right horizontal nystagmus was demonstrated.