Mental imagery and relearning for patients suffered from stroke

xvii, 269 leaves : ill. ; 30 cm.PolyU Library Call No.: [THS] LG51 .H577P RS 2002 LiuThis study examines the use of mental imagery in promoting the relearning potential of patients with stroke. Mental imagery is high-level cortical activity which has a positive effect on the planning and execution of task performance. It is postulated that mental imagery would improve the relearning of trained and untrained tasks and thus increase the generalization power of the skills learnt for patients with stroke. A total of 46 patients diagnosed with middle cerebral artery region infarction with a mean age of 71.4 years were matched and randomly assigned to the experimental (n = 26) and control groups (n = 20). The experimental intervention was the mental imagery program of relearning (MIP-R) consisting of chunking, self-regulation, and mental rehearsal training components. The control intervention consisted of a conventional occupational therapy program that used rote learning. The frequency of training in both programs was 5 times a week for 3 weeks with a duration of 60 minutes per session. All patients also received standardized physiotherapy training. In both programs, the patients were required to learn how to perform 15 complicated daily tasks. All patients were evaluated on their performance at each week. The performance of 5 trained tasks in the last week of die program was evaluated at the post-program, 1-week post-program, and 1-month post-discharge intervals. At the post-program assessment, patients were also tested on their performance at 5 untrained tasks. In addition, patients' abilities in regard to sensori-motor, verbal-spatial-cognitive, and emotional adaptive factors were assessed using different instruments at the pre- and post-program intervals. The results indicated that patients in the MIP-R group showed significantly higher task performance in week 2 and week 3 (F (1, 44) = 7.02, p = 0.011 in week 2; F (1, 44) = 4.22, p = 0.046 in week 3). This effect appeared to be maintained at the 1-week and 1-month intervals (F (2, 43) = 89.42, p < 0.001 for one-week maintenance; F (2,43) = 70.05, p < 0.001 for one-month maintenance). Patients in the MIP-R group also showed a significantly higher performance at untrained tasks (F (2,43) = 71.48, p < 0.001). Among the ability measures, only the Color Trails Test revealed significant differences between patients in the MIP-R and CR groups at the post-program interval (F = 4.50, df= 1, p < 0.05 for Color Trail 1: F = 4.29, df = 1, p < 0.05 for Color Trail 2). The findings suggest that me MIP-R is useful for enhancing the relearning of trained and untrained tasks. The skills learnt seem to remain active after 1-month post-discharge. The connectionist model offers a plausible mechanism explaining the phenomenon of the patients' relearning. The effects of mental imagery seem to improve task performance by improving sustained attention, and the planning and execution function, which are specific to the performance. Future research should focus on modeling the mechanism and neural network of mental imagery with brain mapping and functional imaging technologies. The long-term clinical outcomes in terms of community integration and improvement in the quality of life of patients with stroke should also be studied.Department of Rehabilitation SciencesPh.D., Dept. of Rehabilitation Sciences, The Hong Kong Polytechnic University, 2002