Which target for DBS in Parkinson's disease? Subthalamic nucleus versus globus pallidus internus

We selected 14 patients with advanced idiopathic Parkinson's disease (PD) a nd examined the clinical effects of STN DBS versus GPi DBS. Nine patients u nderwent bilateral STN DBS and five underwent bilateral GPi patients. All p atients were followed for at least 12 months. The evaluation was performed on and off drug before surgery; on-drug/on-DBS and off-drug/on-DBS at 1, 3, 6 and 12 months after stereotactic surgery. At 1 and 3 months after surger y in off-drug/on-DBS condition, both groups showed an improvement in motor score (UPDRS III). Nevertheless, the results changed after long-term stimul ation in the two groups. Chronic STN DBS is superior to GPi DBS in the amel ioration of the clinical features and in the decrease of time spent in the off state. The efficacy in reduction of LID was comparable at 1 and 3 month s after surgery, but the results were better in STN DBS after chronic stimu lation. The L-dopa dose was reduced only in the STN group.