Apogeotropic Posterior Semicircular Canal Benign Paroxysmal Positional Vertigo: Some Clinical and Therapeutic Considerations

Abstract

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.

Figure 1.

Paroxysmal positional nystagmus due to unilateral right posterior semicircular canal benign paroxysmal positional vertigo (inhibitory stimulus). A and B) Arrows indicate the direction of nystagmus slow phase in the two eyes; C and D) arrows indicate the ocular muscles involved in nystagmus generation; E and F) the two labyrinths; arrow indicates the endolymphatic flow within the affected canal. A, C and E) The right eye and the right labyrinth; B, D and F) the left eye and the left labyrinth. A, anterior semicircular canal; L, lateral semicircular canal; P, posterior semicircular canal.

Figure 2.

The nystagmus does not fatigue to repeated positionings. Curved arrows: movements of posterior semicircular canal (PSC) during positionings (head hanging positionings and coming back to sitting position). Straight lines: portion of the PSC in which the debris is trapped.

Figure 3.

Schematic representation of demi Semont maneuver for a left apogeotropic variant posterior semicircular canal benign paroxysmal positional vertigo (see the text for details). CSP, posterior semicircular canal; CSA, anterior semicircular canal; CSL, lateral semicircular canal.

Figure 4.

Schematic representation of 45° FPP technique for a left apogeotropic variant posterior semicircular canal benign paroxysmal positional vertigo (see the text for details). CSP, posterior semicircular canal; CSA, anterior semicircular canal; CSL, lateral semicircular canal.