Early outcome of subthalamic nucleus deep brain stimulation (STN-DBS) in advanced parkinson disease in first trial of Iranian patients

To improve the debilitating features of Parkinson disease (PD) different medical and surgical approaches are available. Subthalamic nucleus deep brain stimulation (STN-DBS) was appeared to be a promising method during last two decades. This study aimed to evaluate early motor outcomes of this procedure in first trial of Iranian patients.

Thirty-seven consecutive patients with advanced Parkinson disease with poor response to common medical agents underwent bilateral STN-DBS. For assessment of motor function parameters Unified Parkinson Disease Rating scale III (UPDRS III) was used. We compared total scores and subscores in three measurements performed as 1) preoperative off-medication, 2) preoperative on-medication and 3) six months postoperative on stimulation and on medication. Reduction in drug consumption was assessed with regard to administered doses of L-Dopa before and after surgery in stable states.

26 men and 10 women with mean age of 50 years were evaluated (one person expired before 6-month follow-up). Mean total scores of UPDRSIII were calculated as 5.2±54.52, 2.88±18.22 and 3±12.8 in three measurements, respectively (p=0.003). PostHoc analyses showed significant improvement among all measurements. Analysis of subscores also revealed significant amelioration in rigidity, resting tremor, hand movement, leg agility, finger tap and rapid alternating movement in on-medication phases of pre- and post-operation (all with p<0.01). The mean administered L-Dopa were224±1296 mg/d and 174±782 mg/d before and after surgery, with significant decline (p<0.001) in administered L-dopa dose.

The results indicate that bilateral STN-DBS can lead to significant short-term improvement of the motor symptoms especially in some debilitating symptoms such as rigidity and tremor in advanced PD. It also accompanies with remarkable reduction in needed doses of drugs. The findings support other studies with similar follow - up interval; however, continuous evaluations are needed for long-lasting effects.