Over the years, a number of eminent researchers have indicated that once we begin a study of nystagmus we literally fall into a labyrinth and eventually we reach a point wherein we are at a loss as to what to do. This statement is obviously a negative approach, but it cannot be denied that such a view has created obstacles in the development of current neurotology. There are various reasons underlying this viewpoint, and one may be that previously, researchers approached the study of nystagmus by observing patients with multiple sclerosis.
Confusion generally results from the fact that multiple sclerosis lesions appear randomly and are distributed throughout most of the nervous system. Current otological research approaches the study of nystagmus from the basis of the peripheral labyrinth which, in turn, exerts a definite influence on ocular movements. Research on nystagmus has steadily advanced from the labyrinth to retro-labyrinthine structures and currently includes the central nervous system. This report is accompanied by a discussion of the relationships between eye movements and lesions located in the mesencephalon, pons, medulla, dorsal portion of the brain stem, the brain stem in general, the hemispheric portion of the cerebellum, cerebellar vermis and cerebral hemispheres. General disorders of the CNS and the labyrinth are also considered.