In some parkinsonian syndromes the patients might have a good response to levodopa initially which might be lost. Patients who cannot tolerate levodopa due to adverse effects. Patients have disabling motor fluctuations or dyskinesias. Patients have tried presently available medications for PD and either continue to be disabled or cannot tolerate the medications due to side effects. Patients should not have memory impairment.
Patients usually undergo formal memory testing before surgery.
Patients should not have pacemaker. Patients are in otherwise good health to be able to tolerate the duration of surgery and programming. MRI of the brain does not show any significant abnormality. It does not help with any other PD symptoms. Surgery is usually performed on one side of the brain.