Efficacy of tailored computer-based neurorehabilitation for improvement of movement initiation in Parkinson's disease.

While Parkinson's disease (PD) is considered a motor disorder, motor signs of PD can be exacerbated by cognitive dysfunction. We evaluated the efficacy of a computer-based cognitive rehabilitation training program designed to improve motor-related executive function. Thirty people with PD and 21 controls participated in the 10-day training. Training consisted of a two-phase button press task. First, subjects produced an externally cued (EC) digit sequence, typing numbers displayed on the computer screen. Second, subjects were prompted to generate the same sequence in the absence of the number display (internally represented sequence, IR). Sequence length was automatically adjusted to maintain 87% correct performance. Participants were evaluated before and after training using a fixed version of the training task, and generalization of training was assessed using measures involving IR motor sequencing, switching and activities of daily living. PD participants were divided into two groups, those who showed impairment in IR motor sequence production prior to training (N=14) and those whose performance was similar to controls (N=16). Following training the impaired PD group showed significantly greater reduction in sequence initiation and completion time and in error rate for IR conditions compared to the unimpaired PD and control groups. All groups improved on Trails B-A, and pre-training Trails B was identified as a predictor of training-based improvement in IR sequence completion time and error rate. Our findings highlight the importance of neurorehabilitation tailored to the specific cognitive deficits of the PD patient.