There are indications that STN stimulation slows down the progression of the disease. The patients who had STN three years whom I followed did not have to adjust their medication and have not worsened. In advanced Parkinson's disease you would have expected a considerable worsening over a period of three years. Prof. Benabid from Grenoble has similar experience and even over a time period of 5 years. He is in favor to start STN stimulation at an earlier stage and considering my own experience I have to agree with him. Chris van der Linden, M.D.