Studies on body sway of patients with unilateral peripheral vestibular disorder--with special reference to characteristic sway in various stages of spontaneous nystagmus

Abstract

In order to investigate the influence of the status on body sway, 60 normal persons and 73 patients with unilateral peripheral vestibular disorder were examined by stabilometry. Results were analyzed, by signal processor 7T17 (NEC, SANEI), with respect to three basic components: extent, speed and direction of body sway.The affected side of the patient was decided by neurotological examinations and the status of the diseased labyrinth was diagnosed as or paralytic, by the direction of spontaneous nystagmus.From this investigation, the following results were obtained:1) The extent of body sway in patients with spontaneous nystagmus was greater than normal, and the speed of body sway towards the direction of spontaneous nystagmus was faster than that in the opposite direction.2) A characteristic difference in body sway between the patients showing irritative nystagmus and the patients showing paralytic nystagmus was observed in the direction component. In the irritative stage, divergence of body sway was observed and patients fluctuated to all directions. In contrast, patients in the paralytic stage fluctuated to the right and left sides, thus the characteristic sway in this stage was lateral.3) Patients without spontaneous nystagmus, in spite of showing labyrinthine preponderance by Contraves computerized rotary chair system, did not sway beyond the normal range. This discrepancy was thought to be caused by neurophysiological differences between the vestibuloocular reflex and the vestibulo-spinal reflex.