Deep brain stimulation for Parkinson's disease - patient selection.

Proper selection of patients who will reliably benefit from deep brain stimulation (DBS) is critical to its success. This requires careful evaluation that should be delivered by an expert multidisciplinary team involving a movement disorder neurologist, a neurosurgeon, a neuropsychologist, and a psychiatrist. The most suitable candidates for DBS suffer from Parkinson's disease with motor fluctuations and/or dyskinesias that are not adequately controlled with optimized medical therapy, or with medication-refractory tremor. During the best on-motor periods, gait difficulties, instability, and speech problems should be minimal, reflecting an excellent response to levodopa in the ideal candidate. The cognitive, psychiatric, and behavioral status must be normal or minimally affected, with the exception of dopamine agonist drug-induced impulse control disorders, which are usually improved after successful surgery and drug withdrawal. Moreover, the patients have no serious comorbidities. Most patients corresponding to this profile suffer from a relatively young onset of Parkinson's disease, and are aged less than 70 years at the time of surgery. Indeed, most patients fall outside this ideal description, and the medical art is to appreciate for each patient the extent to which the alterations of these features can be accepted. Eventually, patients make their own decision from detailed information of their individualized risks and benefits of DBS. Patient expectations, cooperation, and familial support are also important considerations.