Fig. 3.

Pseudo-Spontaneous Nystagmus: (A) LSC is bent 30° compared to horizontal plane, in patient seated with head in axis with the body, it works as an inclined plane where otoliths can slowly float. PSN beats towards healthy ear in geotropic forms (GEO), whereas it beats towards affected ear in apogeotropic forms (APO). (B) When patient’s head is bent forwards, pseudo-spontaneous Ny inverts its direction, (A) when head is returned in axis with body or (C) is bent backwards it beats again in the initial direction. Changing LSC bending angle, otoliths change direction and velocity, settling along the canal, consequently, PSN increases intensity when head is bent backwards and LSC is approximately bent 60° on horizontal plane (C).