VISUAL-VESTIBULO-OCULAR INTERACTIONS IN PATIENTS WITH CENTRAL NERVOUS SYSTEM DISORDERS

Abstract

In 112 patients with focal lesions of the central nervous system, the visual-vestibulo-ocular reflex (VVOR) and the vestibulo-ocular reflex (VOR) gains were examined and compared with other otoneurological findings.
The various types of abnormal VOR and VVOR gains were observed in 112 patients with well-defined central nervous system disorders. Decreased VOR and VVOR gains were frequently seen in patients with the brain stem lesions and in those with combined cerebellar and brain stem lesions.
Results of VOR and VVOR tests were as follows.
1. These tests are useful not only as screening tests but also for the topodiagnostic evaluation of central nervous system lesions.
2. Because the changes of VOR and VVOR gains parallel with the clinical symptoms, they are useful and appropriate systems for following the progress of central nervous system disorders as is the case in peripheral vestibular disorders.
3. It is suggested that VVOR is consisted of the algebraic summation of VOR and OKN, and the interaction of VOR and OKN was regulated mainly by the brain stem function.
4. The abnomal VOR and VVOR gains were not always associated with abnormal visual fixation of caloric nystagmus, so there might have been some different mechanism between VVOR and the visual fixation of caloric nystagmus from the standpoint of clinical examinations.
5. The examination of VOR and VVOR together with other otoneurological tests, leads us the better understanding of the pathology of the brain stem and cerebellum.