[Critical review of the subthalamic stimulation in Parkinson's disease].

The authors critically review subthalamic nucleus (STN) stimulation for Parkinson's disease (PD) at long follow-up (3-5 years). Subthalamic stimulation induce a significant improvement during the "off" medication in the assessment motor score UPDRS (Unified Parkinson Disease Rating Scale) 3-5 years after surgery. Results show that the benefits obtained in tremor, rigidity, bradykinesia, dyskinesias induced by medication and levodopa reduction are significantly maintained during long term. The improvement in other clinical signs as gait and postural stability at long follow-up are not maintained comparing with the benefits obtained one year after surgery. A high percentage of patients show a cognitive disturbance during the follow-up period that may be correlated with the disease progression. The conclusion is that bilateral STN stimulation is an effective treatment for PD patients at long term but it should be considered earlier in the course of PD.