Biomedical subjects

Douglas Watt

Publications and source records attributed to Douglas Watt.

3 recordsLinked to original sources

PubMed2004

2-year review of a novel vestibular rehabilitation program in Montreal and Laval, Quebec.

OBJECTIVE: To evaluate the benefits of a vestibular rehabilitation program (VRP) in the Montreal-Laval area. DESIGN: The VRP was conceptualized by a panel of experts including otolaryngologists, physiotherapists, and researchers from McGill University and its teaching hospitals. From February 1999 to December 2001, 117 patients were seen, and 88 of them completed the VRP. SETTING: The VRP has been established at the Jewish Rehabilitation Hospital in Laval, PQ, to provide specialized rehabilitation to clients suffering from vertigo, dizziness, and/or impaired balance owing to lesions or disorders of the vestibular system. MAIN OUTCOME MEASURES: Presence or absence of nystagmus or vertigo during the Dix-Hallpike test, Dizziness Handicap Inventory (DHI), and Dynamic Gait Index (DGI). RESULTS: Thirty-five patients with benign paroxysmal positional vertigo of the posterior canal were treated with canalith repositioning manoeuvres. All of the patients (100%) had absence of nystagmus or vertigo after one to four treatment sessions. Forty-six patients with vestibular deficits or dizziness-disequilibrium completed the VRP, which consisted mainly of individualized eye-head and balance home exercise programs. At the end of the VRP, there was a significant decrease in DHI score (31 vs 57; p < .01) and a significant increase in DGI score (18.4 vs 22.6; p < .01). CONCLUSIONS: A range of modest to major improvements was shown by comparing initial and discharge scores of patients who had completed vestibular rehabilitation. The VRP appears to be beneficial for patients with a variety of vestibular disorders. Further research is needed to continue optimizing vestibular rehabilitation.

Female↗

PubMed2003

Spatial navigation after surgical resection of an acoustic neuroma: pilot study.

OBJECTIVE: To characterize navigation errors made by patients with the absence of vestibular function on one side owing to surgical resection of an acoustic neuroma. METHODS: Seventeen young (18-38 years) and 9 older healthy individuals (67-83 years), as well as 5 patients 2 to 20 months following surgery (37-61 years), were studied. They sidestepped laterally with eyes closed toward memorized targets located 1.25 m to their right or left. They stopped when they judged that they were in front of the target. The position of head and body markers was recorded in three dimensions with a six-camera Vicon 512 system (Oxford Metrics Ltd., Oxford, UK). Navigation errors were (1) distance error, the distance between the end target and a perpendicular line drawn from the sternum to the plane of targets, and (2) deviation, the angle formed between the line joining the initial and end targets and the line joining the subject's shoulders. RESULTS: Mean distance error was 20.9 +/- 22.0 degrees cm in patients, 29.6 +/- 30.3 cm in young healthy subjects, and -1.7 +/- 18.4 cm in older subjects (p < .01 compared with young subjects). Mean deviation was symmetric and 8 degrees and -3 degrees in healthy young and older subjects, respectively. In contrast, patients had a significantly larger deviation when navigating toward the side of their lesion than the intact side (13 degrees +/- 9 degrees versus 3 degrees +/- 9 degrees; p < .01). CONCLUSIONS: Our results suggest that patients with vestibular deficits have impaired ability to control body rotations when walking sideways without vision toward the side of their vestibular lesion.

Adolescent↗

PubMed2003

Vestibular suppression during space flight.

Normal movements performed while voluntarily fixing the head to the torso can lead to motion sickness in susceptible individuals. The underlying mechanism may involve excessive suppression of vestibular responses. A similar motor strategy is often adopted in the early days of a space flight and might contribute to the development of space motion sickness. In a recent experiment, we monitored the eye, head and upper torso rotations of four Life and Microgravity Spacelab crew members. For the purposes of this study, all data were excluded except for periods during which the subject was performing pure yaw-axis head movements. All subjects showed a significant increase in gaze slip on the first day of their mission, suggesting that increased vestibular suppression was occurring. Furthermore, this amount of increased suppression would have been more than adequate to produce motion sickness in susceptible individuals on the ground. The results support the theory of two, independent mechanisms for space motion sickness.

Fixation, Ocular↗