ICBII Update on the Road to the Cure - April 2023

Parkinson’s disease is the most common neurodegenerative movement disorder characterized by bradykinesia, rigidity, postural instability, and tremor at rest. Dopamine replacement therapy is the gold standard treatment for Parkinson's, but there is a subset of tremor-dominant Parkinson's patients for whom medical therapy does not achieve successful tremor control. Deep brain stimulation (DBS) targeting the subthalamic nucleus, globus pallidus internus, and ventral intermediate nucleus of the thalamus has become widely used. DBS requires an open cranial procedure for device implantation, which is associated with the risk of hemorrhagic and infectious complications.

University of Maryland School of Medicine (UMSOM) has developed a device, Exablate Neuro, to treat advanced Parkinson’s disease on one side of the brain. This device that uses Focused Ultrasound to treat symptoms was approved by the US FDA in November 2022.  

How Exablate Neuro Works

Focused ultrasound is an incisionless procedure, performed without the need for anesthesia or an in-patient stay in the hospital. Patients, who are fully alert, lie in a magnetic resonance imaging (MRI) scanner, wearing a transducer helmet. Ultrasonic energy is targeted through the skull to the globus pallidus, a structure deep in the brain that helps control regular voluntary movement. MRI images provide doctors with a real-time temperature map of the area being treated. During the procedure, the patient is awake and providing feedback, which allows doctors to monitor the immediate effects of the tissue ablation and make adjustments as needed.

Soon after treatment begins, patients often experience relief from severe symptoms such as tremors, rigidity in the legs and arms, and side effects from medications that cause involuntary, erratic movements called “dyskinesia.” In a pilot study involving 20 Parkinson’s patients that underwent focused ultrasound, the vast majority of patients experienced a clinically meaningful improvement in their motor skills, like tremors, that lasted through one year of follow-up. Only one patient experienced progression of the disease during that time. A more recent randomized controlled study involving 89 patients, a third of whom initially had a sham procedure, yielded similar results which led to the device approval by the FDA. 

Focused ultrasound is not a cure. However, it can provide symptomatic relief for a year or so to eligible Parkinson’s patients whose advanced disease is on one side of the brain. Parkinson’s patients may want to discuss with their neurologists before contacting centers such as UMSOM that offer focused ultrasound treatment.