Surgery

Brain surgery is an option for advanced PD patients whose symptoms can no longer be adequately managed with medications. The best surgical candidate is someone who:

• Responds well to dopaminergic therapy
• Has motor complications (off periods and dyskinesias) that are limiting factors
• Is otherwise healthy and a good surgical risk.

Advanced age is not necessarily a barrier to surgery, but impaired cognition, including forgetfulness, diminished decision-making ability, and language difficulties, along with gradual loss of brain matter (brain atrophy or shrinkage), make the surgery more risky and decreases the likelihood of an optimal outcome.

Depending on the patient, procedure, and skill of the operating team, cognition may be mildly impaired or largely unaffected by the surgery itself. The most commonly reported adverse cognitive effects are reduced decision-making abilities and language impairments.

It is impossible to predict the benefit any individual patient can expect from surgery. The general rule of thumb is that the maximum benefit is equal to the best response from a dose of levodopa (minus the effect on dyskinesias). Therefore, if a patient's symptoms are 50% better at the peak of a levodopa dose, the surgery is not likely to improve the patient's symptoms more than that amount. Importantly though, improvements from surgery are most dramatic during the times the patient is not experiencing the effects of medications ("off" time). Therefore, surgery may greatly improve the amount of the day during which symptoms are reduced.

	Types of Surgery