Bilateral effects of unilateral subthalamic deep brain stimulation on Parkinson's disease at 1 year.
OBJECTIVE
To quantify the benefit of unilateral subthalamic nucleus (STN) deep brain stimulation (DBS) on contralateral, ipsilateral, and axial symptoms of advanced Parkinson's disease.


METHODS
Thirty-seven patients received unilateral STN DBS and were rated on the Unified Parkinson's Disease Rating Scale (UPDRS) and timed tests of motor function in the "practically defined off" state at baseline and at 3, 6, and 12 months postoperatively.


RESULTS
UPDRS motor scores improved significantly at 3, 6, and 12 months relative to the preoperative baseline (P < 0.001, 37.1% at 1 year). There was improvement in the contralateral UPDRS subscores (P < 0.001, 54.6% at 1 year), and although contralateral benefit was larger on all outcome measures, ipsilateral benefit was present at 3 and 6 months on the UPDRS subscore (P = 0.013 and 23.5%, P = 0.005 and 27.7%, respectively). A trend toward ipsilateral benefit was present on the UPDRS subscore at 12 months; however, the effect was not statistically significant. Two timed tests of motor function in the upper extremities showed significant ipsilateral benefit in bradykinesia at 12 months (P < 0.001 and P = 0.014, respectively). Significant benefit was also observed in the UPDRS part 2 "off" medications and the UPDRS part 4 after unilateral STN DBS at 12 months (both P < 0.001).


CONCLUSIONS
Considering the bilateral effects and tolerability of unilateral STN DBS, unilateral stimulation followed by a contralateral procedure later, if necessary, is a reasonable option for patients with advanced Parkinson's disease, especially with prominent asymmetry.
Walker
Harrison C
HC
Department of Neurology, Division of Movement Disorders, University of Alabama at Birmingham, Birmingham, Alabama 35294-0017, USA. hcwalker@uab.edu
Watts
Ray L
RL
Guthrie
Stephanie
S
Wang
Deli
D
Guthrie
Barton L
BL
D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage; D046690:Deep Brain Stimulation / Q000379:methods* / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D018476:Hypokinesia / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D009460:Neurologic Examination; D017063:Outcome Assessment, Health Care; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy*; D020127:Recovery of Function / Q000502:physiology*; D020531:Subthalamic Nucleus / Q000033:anatomy & histology / Q000502:physiology*; D013995:Time; D013997:Time Factors; D016896:Treatment Outcome
D000978:Antiparkinson Agents