Deep brain stimulation or medical therapy: which is more effective for advanced Parkinson’s disease?

This study investigated the effectiveness of deep brain stimulation (DBS) and/or medical therapy for patients with advanced Parkinson’s disease. This study concluded that DBS plus medical therapy improved Parkinson's symptoms and quality of life compared to medical therapy alone.

Levodopa remains the mainstay of Parkinson’s disease therapy. However, many patients with advanced Parkinson’s experience motor complications with long-term levodopa use.

Deep brain stimulation involves an electrode surgically implanted into a specific part of the brain. Typically, DBS is performed in the GPi (globus pallidus internus), the STN (subthalamic nucleus), or the thalamus. It is not clear which of these regions is the best target for treating Parkinson’s symptoms. The effectiveness of DBS combined with medication versus medication alone also remains under investigation.

This analysis combined the results of 16 other studies. These studies involved 2186 patients. Patients received DBS in the GPi or the STN with or without medical therapy (levodopa). Treatment effectiveness and quality of life changes were assessed using standard questionnaires. Follow-up ranged from 6 months to 3 years.

There were no significant differences between GPi-DBS and STN-DBS in improvement of symptoms.

Compared to medical therapy, GPi-DBS improved motor symptoms in patients who either were or were not responding to medication. GPi-DPS improved daily activity functioning in patients who were not responding to medication but did not significantly affect patients who were responding.

STN-DBS also improved daily functioning compared to medical therapy in all patients. It also improved motor symptoms and complications of treatment in patients who were responding to medication. There was no significant difference in patients who were not responding to medication.

GPi-DBS significantly improved quality of life compared to STN-DBS. Patients undergoing STN-DBS were able to lower their medication dosage more so than those undergoing GPi-DBS.

This study concluded that DBS plus medical therapy greatly improved PD symptoms and quality of life compared to medical therapy alone. GPi-DBS led to greater improvements in quality of life, while STN-DBS reduced use of medications.