Affiliations: Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, TX 77030, USA
Note: [*] Correspondence to: Helen Cohen, EdD, OTR, Department of Otorhinolaryngology, Baylor College of Medicine, One Baylor Plaza,
Houston, TX 77030, USA. Tel.: +1 713 798 6336; Fax: +1 713 798 8658; E-mail: hcohen@bcm.tmc.edu
Abstract: The goal of this study was to determine if people use vestibular information to keep track of their positions while walking through a simple course. Subjects were normals and patients with chronic peripheral vestibulopathies – each of whom were tested once – and patients with acoustic neuromas tested pre- operatively and one and three weeks post-operatively. Subjects walked over a straight course, 7.62 m, with their eyes open and then with their eyes closed. The time needed for task performance, the forward distance subjects walked before veering, and the lateral distance subjects veered from the straight ahead were recorded. The angle of veering was then calculated. Normals were able to perform this task easily with eyes open or closed. With eyes closed pre-operative acoustic neuroma subjects walked significantly shorter distances before veering than normals but did not veer significantly more than normals or take longer than normals to perform the task. Chronic vestibulopathy subjects, by contrast, were significantly impaired compared to normals on all measures. With eyes open within a week after acoustic neuroma resection subjects could perform the task as well as normals. With eyes closed, however, post-operative subjects were impaired compared to their own pre-operative levels, but they had returned to their pre-operative levels at the second post-operative test. Ataxia was only weakly correlated to any measures and tumor size was not related to performance. These findings support the hypothesis that vestibular input is used for spatial orientation during active motion.
Keywords: veering, spatial orientation, navigation, dead reckoning
