Secondary phase nystagmus--revisited.
A prospective clinical study of secondary phase nystagmus (SPN) is presented. The tracings of 200 patients referred for ENG evaluation and eight normal control subjects were anlyzed under all caloric conditions, within a prolonged postirrigation tracing time frame. The spontaneous direction reversal (SPN) was observed in a majority of the control subjects under all four conditions. The occurrence of post-caloric SPN in the patient group varied considerably among various diagnostic categories. However, SPN was observed far less frequently in the total patient group as compared to the control group. Thus, the absence of SPN may be taken to be a general indication of vestibular pathology.
D004584:Electronystagmography; D006801:Humans; D009759:Nystagmus, Pathologic / Q000503:physiopathology*; D011187:Posture; D011446:Prospective Studies; D012008:Recurrence