A case of hemiplegia with a cerebrovascular accident in which motor imagery of finger extension on the affected side with finger extension on the unaffected side was effective - A study using F-waves

We investigated the effect of exercise therapy by simultaneously using motor imagery of thumb or all finger extension on the affected side and thumb or all finger extension exercise on the unaffected side by using the F-wave, which is used to measure the excitability of anterior horn cells to devise an appropriate exercise therapy using motor imagery for patients with increased muscle tone of the thumb muscles on the affected side. Tasks 1, 2, 3, and 4 involved motor imagery of thumb extension on the affected side, motor imagery of finger extension on the affected side, motor imagery of thumb extension on the affected side based on thumb extension on the unaffected side, and finger extension on the affected side based on finger extension on the unaffected side, respectively; conducted in three trials, with one week or more between each trial. Each task was performed for one minute, with a five-minute interval between tasks. The F-waves from the thenar muscles were recorded with median nerve stimulation on the affected side before and during the tasks. The relative values of the F-wave data of the task and the F-wave data before (resting state) and during the tasks were calculated. In results, the relative data of the F/M amplitude ratio in task 4 was lower than that in the other tasks in three trials. In conclusion, motor imagery of finger extension on the affected side with finger extension movement on the unaffected side was effective for improving the muscle tone of the thenar muscles on the affected side.