Bimanual force coordination in Parkinson's disease patients with bilateral subthalamic deep brain stimulation.
OBJECTIVE
Studies of bimanual actions similar to activities of daily living (ADLs) are currently lacking in evaluating fine motor control in Parkinson's disease patients implanted with bilateral subthalamic deep brain stimulators. We investigated basic time and force characteristics of a bimanual task that resembles performance of ADLs in a group of bilateral subthalamic deep brain stimulation (DBS) patients.


METHODS
Patients were evaluated in three different DBS parameter conditions off stimulation, on clinically derived stimulation parameters, and on settings derived from a patient-specific computational model. Model-based parameters were computed as a means to minimize spread of current to non-motor regions of the subthalamic nucleus via Cicerone Deep Brain Stimulation software. Patients were evaluated off parkinsonian medications in each stimulation condition.


RESULTS
The data indicate that DBS parameter state does not affect most aspects of fine motor control in ADL-like tasks; however, features such as increased grip force and grip symmetry varied with the stimulation state. In the absence of DBS parameters, patients exhibited significant grip force asymmetry. Overall UPDRS-III and UPDRS-III scores associated with hand function were lower while patients were experiencing clinically-derived or model-based parameters, as compared to the off-stimulation condition.


CONCLUSIONS
While bilateral subthalamic DBS has been shown to alleviate gross motor dysfunction, our results indicate that DBS may not provide the same magnitude of benefit to fine motor coordination.
Department of Health and Human Performance, University of Houston, Houston, Texas, United States of America ; Centers for Neuromotor and Biomechanics Research and Neuro-Engineering and Cognitive Science, University of Houston, Houston, Texas, United States of America.
Stacey L
SL
Gorniak
Cameron C
CC
McIntyre
Jay L
JL
Alberts
D003198:Computer Simulation; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009068:Movement; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000503:physiopathology