Insightec’s Exablate Neuro is approved in the US, Canada, Europe, Israel, Korea, Japan, and Russia for the treatment of essential tremor. It is also “CE marked” (a manufacturer’s indication that a product conforms with relevant legislation applicable to their product and therefore is permitted for use) to treat Parkinsonian tremor and neuropathic pain. Researchers around the world are working to assess the system in the treatment of several other related movement disorders.
Current research involving focused ultrasound for other movement disorders includes:
- Tremor from Parkinson’s Disease (PD): A subset of patients with PD have tremor as their primary disabling symptom. Like essential tremor, PD tremor can be treated with a similar intervention by MR-guided focused ultrasound (FUS) in the ventral intermediate (VIM) thalamus. The treatment is available in Europe, Russia, Korea, and parts of the Middle East. In the US, a pilot trial has been completed.
- Dyskinesia and other symptoms associated with PD: Often, the most disabling symptoms of PD involve dyskinesia, rigidity, and bradykinesia. These symptoms can often be treated with a lesion in the globus pallidus (GPi). Pilot studies have been completed on pallidotomies with FUS and show encouraging results (similar to historical studies with open surgical pallidotomies). Insightec is planning to begin a pivotal clinical trial in 2017 to initiate the process to make this treatment available.
A note about tremor versus dyskinesia: Dyskinesia is a distortion or impairment of voluntary movement that generally occurs due to levodopa medication taken by a patient with PD. With dyskinesia, a person is unable to control muscle movement. Dyskinetic movements look like smooth tics and can include writhing and twisting movements. Tremor is also an involuntary movement, but it is characterized by a rhythmic shaking or vibrating movement. A resting tremor is found in a majority of persons with PD. It normally starts in one hand and is most prominent when the hand is resting and relaxed. Additional symptoms in PD include joint rigidity and overall bradykinesia – or slowness of movement.
- Focal Dystonia: A pilot trial is under way at Tokyo Women’s University/Shin-Yurigoaka Hospital in Japan to evaluate FUS for the treatment of certain focal hand dystonias. These patients experience loss of control in performing specific hand movements (e.g., writer’s cramp), which can lead to the inability to continue in their profession or with certain hobbies or daily activities. The interventional target to treat is related to the other FUS targets in the VIM thalamus or GPi.