[Analysis of antiparkinsonian drug reduction after bilateral subthalamic deep brain stimulation]

Bilateral deep brain stimulation of the subthalamic nuclei (STN) is a well-established and cost-effective treatment in advanced PD.

To quantitatively analyze the change in use of antiparkinsonian drugs one year after subthalamic deep brain stimulator (DBS) implantation in patients with idiopathic Parkinson's disease (PD).

Eighteen consecutive patients with advanced PD underwent bilateral STN DBS implantation were involved in the study. The stimulation achieved a stable and clear clinical benefit in all of the cases. One year after the implantation, drug usage of patients was analyzed and correlated with the postoperative symptomatic improvement measured by the modified Hoehn-Yahr, Schwab and England, and Unified Parkinson's Disease Rating Scales. Because none of the investigated variables followed the normal distribution, non-parametric Wilcoxon signed-rank, McNemar and Kendell's T tests were applied.

Preoperatively, the patients used 12.05 +/- 4.57 tablets a day out of 3.19 +/- 0.97 different antiparkinsonian drugs, which was significantly reduced by deep brain stimulation to the application of 7.00 +/- 2.96 tablets out of 1-3 (1.84 +/- 0.76) drugs (p < 0.001). Meanwhile, the usage of amantadine, MAO-B and COMT inhibitors was also significantly decreased (p < 0.05). The dosage of dopaminerg medication was significantly lowered from 1136 mg to 706 mg expressed in levodopa equivalent dosage (p < 0.001) whereas the UPDRS-III also improved by 48.6%.

Our study is in accordance with previously published international findings that antiparkinsonian medication can be significantly lowered after bilateral STN DBS. Because not only the dosage, but also the applied number of tablets were decreased, it may have resulted in a better compliance and quality of life.