Deep brain stimulation in Parkinson's disease, tremor and dystonia:: Patient selection

The proper selection of patients is critical for the outcome in surgical relief of movement disorders. Considering the risks of a stereotactic intervention, the following premises must apply: 1. the motor symptoms lead to a relevant disability in activities of daily living despite optimal medical treatment, 2. biological age of the patient is not significantly higher than 75 years, 3. there are no neurosurgical contraindications, 4. the patient is neither demented nor severely depressed. If these conditions are fulfilled, the individual chances of improvement of the target symptoms need to be checked, based on the following guidelines: Akinesia can be improv-ed only in levodopa-sensitive parkinsonism. The outcome of surgery for tremor depends on the clinical type and distribution. Distal limb tremors are more easy to supress than proximal limb tremors. Intention tremor is more difficult to treat than rest or postural tremor. Primary dystonia has a better prognosis than secondary dystonia. The best results are seen in children with primary and rapidly progressive generalised dystonia. The indication for surgical treatment depends on the analysis of the individual risk-benefit ratio, which also has to take into consideration the social, professional and familiar background. The patient must be well informed on his risk-benefit ratio and on alternative treatments, before he can take his decision. The selection of patients with movement disorders for deep brain stimulation is a common neurological and neurosurgical task.