The effectiveness of drug therapy to alleviate Parkinson’s disease (PD) symptoms often diminishes over time, and side effects such as dyskinesia (involuntary movements) can become prevalent and burdensome. The destruction of a small volume of tissue near the center of the brain (pallidotomy) can often reduce the dyskinesia, yet typical procedures require surgery or a high dose of focused radiation. This study will investigate the safety and effectiveness of magnetic resonance (MR) guided focused ultrasound as a completely noninvasive method of pallidotomy.
A total of 15 Parkinson’s patients with dyskinesia will be enrolled and treated, divided over three international sites. Before treatment, each patient’s symptoms will be assigned a baseline score. All patients will undergo MR-guided focused ultrasound treatment, in which multiple intersecting beams of ultrasound energy are focused with high precision and accuracy on target cells in the brain (pallidum). The energy will heat and destroy the abnormal cells without harming adjacent tissue, similar to using a magnifying glass to focus beams of light to burn a hole in a leaf. Following treatment, patients will be assessed (e.g. symptom scores, adverse events) at several timepoints including 3 and 12 months after focused ultrasound.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
MR-guided focused ultrasound as a completely noninvasive method of pallidotomy has the potential to reduce Parkinson’s dyskinesia for many patients who no longer find drug therapy effective and/or tolerable. Focused ultrasound treatment is performed with the patient awake, and involves no anesthesia, incisions in the skull or insertion of electrodes into the brain. This could be an effective option for patients who are not candidates for surgery or do not wish to undergo an invasive procedure.
We expect to see significant, immediate and durable improvement in patient symptoms. We also expect to see very minimal and non-significant complications following focused ultrasound, comparable to other ablative techniques such as radiofrequency ablation, with no infection, bleeding or neurological deficits. If the results of this pilot trial are encouraging, it will lead to a larger pivotal trial to gain full regulatory approval.
This grant was selected by The Michael J. Fox Foundation staff to be highlighted via the Foundation’s Partnering Program.