Clinical application of saccade-reflex testing in man.

Computer-aided measurements of saccade-reflex reaction times, velocities, and accuracies have become important tools in the detection of central nervous system pathology. Because of improved knowledge of the reflex pathways in man, saccade testing can assist in differentiating between brain stem, cerebellar, or cerebral disorders and point toward unilateral lesions. Saccade-reflex testing is also useful in determining disability and measuring over time the course of central nervous system disorders. Further work, correlating lesions observed by high-resolution imaging techniques with abnormalities in reflexes, continues to improve the understanding of saccade mechanisms in man. Specific cases are used to show the effects of anatomic lesions on changes in saccade reflexes. The results from 100 consecutive patients evaluated for dizziness are provided in order to illustrate the prevalence of saccade abnormalities and the relationship between abnormalities in vestibular and slow and fast eye-movement reflexes. Patients complaining of disequilibrium and visual disturbances frequently have abnormalities in the saccade system, abnormalities which are often overlooked in present clinical testing of the dizzy patient.