We lately reported the cases of patients complaining positional vertigo whose nystagmic pattern was that of a peripheral torsional vertical positional down beating nystagmus originating from a lithiasis of the non-ampullary arm of the posterior semicircular canal (PSC). We considered this particular pathological picture the apogeotropic variant of PSC benign paroxysmal positional vertigo (BPPV). Since the description of the pilot cases we observed more than 150 patients showing the same clinical sign and course of symptoms. In this paper we describe, in detail, both nystagmus of apogeotropic PSC BPPV (A-PSC BPPV) and symptoms reported by patients trying to give a reasonable explanation for these clinical features. Moreover we developed two specific physical therapies directed to cure A-PSC BPPV. Preliminary results of these techniques are related.
Keywords: 45° forced prolonged position; apogeotropic variant; demi Semont; down beating nystagmus; positional vertigo.