MR guided focused ultrasound (MRgFUS) is an incisionless technique to create very precise lesions deep within the brain. It is one of many tools used in neurosurgery to treat neurological and psyschiatric conditions. The other most common technique is deep brain stimulation.
MRgFUS is a technique which uses ultrasound energy to heat up a very precise target in the brain, creating a permanent lesion. MRgFUS uses a dedicated device to focus the energy from over 1000 ultrasound sources. The ultrasound is applied while the patient is in an MRI machine, so that we can precisely monitor and confirm where the energy is being delivered. The process is safe and has few side effects. It does not require any implants, long-term maintenance, programming, or battery replacements.
MRgFUS is only FDA approved for the treatment of patients with essential tremor. It can only be used to treat one side of the brain (usually the dominant hand) even if tremor is present on both sides. If first line medications (primidone and propranolol) fail to adequately control your tremor, your doctor may consider recommending either MRgFUS, deep brain stimulation, or radiosurgical thalamotomy. Compared to other surgical treatments for essential tremor, no device implant is needed, no incision is required, and the treatment works immediately.
In preparation for treatment, your doctor will order a specialized CT scan to understand your skull anatomy (which can affect your treatment eligibility).
On the day of surgery, a stereotactic frame will be placed on your head to enable exact targeting and to prevent your head from moving during the procedure. At this time, all hair must be removed for treatment, to enable adequate cooling of the scalp. You will be placed in a specialized MR scanner with a MRgFUS helmet, that contains a cooling system as well as the ultrasound sources. You will be awake throughout the procedure and your tremor will be evaluated after each treatment (or sonication). Once the target is confirmed, a lesions is created in a very focused manner using ultrasound energy.
On average, tremor improves by ~50% and effects are sustained in most people up to 6 years after treatment. Only one side will be treated, you will therefore have persistent tremor on the other side. Still, treating one side results in significant improvements in quality of life and function. Side effects include risks of numbness or tingling or walking difficulty, which are rarely serious or disabling.
MRgFUS is not yet available at UCLA, but we anticipate providing this service as of Spring of 2019. In anticipation, we are currently beginning to assess patients for this therapy.