Abstract
Electronystagmography (ENG) provides an objective eye movement record. The resulting nystagmus demonstrates the normality of the vestibular system. If abnormal, is it central or peripheral, right or left? Positional nystagmus is described by the positions found, the direction of beating, and fatigability. The bithermal caloric stimulus results in nystagmus whose fast phase is in opposite directions from the same ear. When the responses are significantly unequal, they can demonstrate a reduced vestibular response or directional preponderance. Failure of ocular fixation to suppress nystagmus is a sign of a central nervous system or oculomotor disorder. © 2014 Elsevier Inc. All rights reserved.