Electronystagmographic findings in patients with cerebral degenerative disease.

Cerebral degenerative diseases produce a variety of abnormal neuro-otological findings on electronystamography (ENG). To assess their diagnostic value and determine which manifestations are helpful in making a diagnosis, ENG findings from 72 cases of confirmed cerebral degenerative disease were analyzed. We observed a high incidence of saccadic pursuit and upward ocular dysmetria, which is likely to be useful in diagnosing cerebral degenerative disease. In contrast, moderate incidences of horizontal ocular dysmetria, gaze-evoked and rebound nystagmus, vertical positioning nystagmus and impaired visual suppression appeared to reflect the degree of dysfunction, while optokinetic nystagmus appeared to reflect both the presence of disease and its severity. Cases of spinocerebellar ataxia 6 and spinocerebellar ataxia 3 tended to produce horizontal and vertical gaze-evoked nystagmus, whereas progressive supranuclear palsy produced a higher incidence of upward gaze-evoked nystagmus, and positioning nystagmus at the sagittal plane appeared frequently in cases of non-hereditary spinocerebellar degeneration.