Deep Brain Stimulation for Parkinson's Disease: When is the Right Time for Deep Brain Stimulation?

Deep brain stimulation (DBS) is an effective and evidence-based treatment option for Parkinson's disease. Studies have shown that DBS has good and long-lasting effects on motor function and quality of life in patients in an advanced stage of the disease and that it is more effective than medical therapy alone. Moreover, a favourable effect of DBS could be detected at an earlier stage of the disease, as well. On the other hand, possible risks and side effects of the procedure need to be taken into consideration. These may manifest as procedure-related complications, such as bleeding and infection, in addition to stimulation-associated phenomena, such as neuropsychiatric disorders and motor side effects. Despite the good effects of deep brain stimulation, clearly there remain important issues to be addressed which will be discussed in this article with consideration of several new randomised and controlled clinical studies. For Parkinson's patients with early fluctuations and dyskinesia, DBS has been found to be superior to the best medical treatment. Therefore, DBS can be considered as a treatment option earlier in the course of the disease. The diagnostic evaluation as well as the exclusion of contraindications are crucial for patient selection. The choice of the target should be based on the individual symptoms in patients, although the subthalamic nucleus (STN) can be considered as the standard target. In any case, an individual assessment of chances and risks must be conducted and realistic goals and reasonable expectations must be defined.