Cognition and eye movements: assessment of cerebral dysfunction.

Background: Many neurological disorders show deficits in ocular motor function. In the past, evaluation has been limited to assessing abnormalities largely generated by pathology of the brainstem andcerebellum. In disorders that primarily or substantially, affect the cerebral hemispheres, disruption of cognitive processes occur, often early in the clinical course. While neuropsychological testing traditionally is used to measure cognitive performance, the cerebral influences on the ocular motor system provides another quantitative paradigm. This review explores the relationship between cognitive sensory processing and execution of planned ocular motor tests in Parkinson's disease, Huntington's disease and multiple sclerosis and explores areas of clinical utility.

Methods: Review of the literature regarding cognitive and ocular motor abnormalities in neurological disease.

Results: The literature indicates that in systems degeneration there are abnormalities of cognitive processing, defined both by conventional behavioural testing and by assessment of cognitive function utilizing ocular motor studies, which characterise those processes. Moreover, in diffuse disease, in processes such as multiple sclerosis, the assessment of cognitive processes involved in ocular motor function may well provide an added level of sensitivity indicating more widespread pathology than would be apparent with conventional clinical assessment.

Conclusions: Assessment of cognitive function in the ocular motor system may provide insight into cerebral function, in health and disease, and may provide both diagnostic information and permit quantification of deficit in future.