Differences in balance and visual characteristics in a group of brain injured patients
Postural stability was measured using a biostereometric sensor in 20 brain-injured subjects and 10 normals. Measurements of stability were recorded for two minutes with eyes open, eyes closed and one eye open in both sitting and standing positions. Based on results of postural measures with both eyes open or closed, brain-injured subjects could be divided into two groups; those whose balance is better with eyes open (E.O. group) and those whose balance is better with eyes closed (E.C. group). Thus, this study documents the clinical impression that some brain-injured subject's static balance is destabilized by vision. A battery of visual sensory, oculomotor and perceptual functions were then examined to identify the extent to which differences in balance in the E.O. and E.C. groups could be explained by differences in one or more of these functions. The E.C. group performed worse on all visual tests as a whole, having significantly worse scores on tests of binocular vision (fine gross) and eye alignment. Many brain-injured subjects may be more readily rehabilitated using monocular vision or without vision. Further investigation of the role of binocular vision in normal postural control may clarify how abnormal binocular vision in brain-injured subjects can result in poor balance.