FDA approves focused ultrasound for tremor-predominant Parkinson’s disease
December 19, 2018 Tremor-predominant Parkinson’s disease (PD) joins Essential tremor (ET) as an FDA-approved indication for the use of Focused ultrasound. Focused ultrasound is a technology in which beams of ultrasound waves are focused on a designated target thereby concentrating enough energy to create a small lesion. When a lesion is created in very specific locations in the brain, it can disrupt the abnormal Parkinson’s circuitry, thereby treating some of PD’s motor symptoms.
Individual ultrasound waves do not contain enough energy to do any damage as they pass through a patient’s skull and brain tissue. It is not until multiple waves are all focused on a particular spot that a lesion is formed. In the recently approved procedure, MRI is used to precisely direct the ultrasound waves to an area of the thalamus, a structure deep in the brain that acts as a relay station for many of the brain’s functions. Abnormalities of thalamic circuitry are known to play a role in tremor and lesioning specific areas of the thalamus decreases tremor. Research of focused ultrasound in other brain regions continues to be explored as possible treatments for PD symptoms such as slowness and stiffness.
Focused ultrasound will not slow the progression of PD, but can help manage the symptoms of the disease. In this way, it is similar to deep brain stimulation (DBS), a surgery in which a wire is inserted into deep brain structures to manipulate the abnormal PD circuitry. DBS of the thalamus treats tremors of PD and ET. (DBS of other brain areas -specifically the subthalamic nucleus or the globus pallidus interna – is used to treat other PD symptoms.) Prior to the advent of DBS, lesioning surgery of the thalamus and other brain areas was used to treat the symptoms of PD. Focused ultrasound can perform approximately the same role as lesioning surgery in a less invasive way. It’s exciting to now have an additional treatment option available for people dealing with tremors from their PD.
The device used to deliver this treatment is called Exablate Neuro and is a product of the company InSightec.