Electronystagmography in the Diagnosis of Central Vertigo

Abstract

Objective: Determine the efficacy and applicability of electronystagmography (ENG) testing in the differential diagnosis between peripheral and central vertigo, through the visual-vestibular interaction test, in patients with vertigo.

Method: Patients were submitted to ENG recording. Patients sat on a rotatory chair, which was placed in the middle of a rotary rotatory cylindrical chamber. The rotatory chamber was driven by a direct current engine, which turned it clockwise and counterclockwise, and its internal area was covered with 32 black vertical contrast.

Results: All patients underwent rotatory vestibular stimulation by Stop test (VOR), optokinetic stimulation (OKN), and contemporary rotatory vestibular and optokinetic stimulation (VVOR). Our experiences highlight as normal that subjects and/or patients affected by peripheral vertigo present a VVOR nystagmus homodirectional to optokinetic nystagmus; patients affected by central vertigo present a VVOR nystagmus homodirectional to vestibular-ocular-reflex (VOR). In healthy patients, VVOR nystagmus is always homodirectional to OKN and indicates the optokinetic system prevalence on VOR.

Conclusion: The presence of a VVOR nystagmus homodirectional to VOR indicates the absence of the optokinetic system prevalence due to a central nervous system (CNS) modification, and highlights a CNS disease. Our data highlight the role of ENG in the diagnosis between peripheral and central vertigo.