High-intensity focused ultrasound is a noninvasive type of neurosurgery for patients with essential tremor; tremor-dominant Parkinson’s disease; or mobility, rigidity, or involuntary movements due to advanced Parkinson’s disease. It was approved for this use by the FDA in 2016; Dr. Kaplitt, who is also a professor of neurological surgery at Weill Cornell Medicine, was the first neurosurgeon in New York to use this procedure to treat essential tremor. Here, he and Dr. Baltuch, who is also professor of neurosurgery at Columbia University Vagelos College of Physicians and Surgeons, explain how surgeons use ultrasound waves to reduce people’s tremors.
Ultrasound beams are focused onto the brain. A patient is in a magnetic resonance imaging (MRI) machine with a helmet that has thousands of sources of ultrasound. These ultrasound beams can safely go through the human skull and enter the brain.
MRI technology guides the ultrasound beams. The MRI machine lets clinicians map out the connections in the brain to better identify not only the circuits in the brain they want to target, but also the nearby circuits to avoid.
All ultrasound beams point to the same spot. Neurosurgeons deliver a large amount of energy to a single point to heat up and destroy the abnormal circuitry. It’s like using a magnifying glass to focus beams of sunlight to burn a leaf or a piece of paper. Removing the dysfunctional circuits in the brain allows the rest of the circuitry to function more normally.
Recovery time is short. Because this is a non-invasive procedure, patients can often go home as soon as an hour after the procedure, with their tremors reduced or gone. Within the NewYork-Presbyterian system, neurosurgeons who perform the procedure collaborate closely with patients’ local neurologists for follow-up care.
Looking at new ways to use focused ultrasound. For movement disorders, high-intensity focused ultrasound is only FDA approved for the treatment of certain movement disorder symptoms. NewYork-Presbyterian and Weill Cornell Medicine are conducting clinical trials and leading research to explore new ways to use this technology.
“Movement disorders are complicated diseases, but we have a very broad network of expertise at NewYork-Presbyterian in surgical and non-surgical treatments,” says Dr. Kaplitt, who is also a professor of neurological surgery at Weill Cornell Medicine. “We were the first academic medical center in New York to have a high-intensity focused ultrasound device and the first to offer this procedure. Through this technology, we’ve given hundreds of patients back their ability to hold a cup or write with a hand they haven’t been able to use, in some cases, for decades.”