Bilateral deep brain stimulation of the subthalamic nucleus in Parkinson'sdisease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is rapidly be coming the preferred surgical choice for the treatment of advanced Parkinso n's disease (PD). We report initial results in 15 patients after 12 months and in nine patients evaluated between 30 and 36 months postoperatively. Ou r experience confirms the robust antiparkinsonian effect of DBS of the STN in advanced PD. The severity of "off" episodes, as assessed by the Unified Parkinson Disease Rating Scale (UPDRS), was drastically reduced by 74% at 1 2 months, and dyskinesia scores (Dyskinesia Rating Scale) decreased. The le vodopa daily dose was reduced by 55% at 12 months. A double-blind assessmen t to determine the effect of stimulation performed in nine patients at 3 mo nths in the "off" medication condition was very significant (p < 0.05). Nin e patients have been followed for 3 years with maintained efficacy in the U PDRS "off" score and the dyskinesia score. The experience of other groups u sing a similar technique is reviewed. The overall assessment indicates a hi gh antiparkinsonian effect of DBS of the STN even in advanced patients. The existence of a learning curve for this procedure should be taken into acco unt when initial results are evaluated.