We are blessed to have the National Parkinson Foundation’s terrific free 1-800-4PD-INFO Helpline staffed by nurses and social workers with experience in the field. Recently, many people have called the Helpline after seeing a video declaring focused ultrasound therapy as “the scalpel-less cure for Parkinson’s disease.” The Helpline staff thought it important to objectively explore this therapy and discuss whether it is indeed a scalpel-less cure.
Conventional deep brain stimulation (DBS) therapy involves drilling a dime-sized hole in the skull and inserting recording and permanent leads directly into a brain target or region. A similar procedure is used for mapping the brain before placing a destructive lesion (thalamotomy, subthalamotomy and pallidotomy). Recently, an alternative ultrasound-based approach has been gaining popularity. High intensity ultrasound was introduced in the 1940s and 1950s as a treatment for a variety of brain disorders. Its recent rebirth has generated a lot of enthusiasm and excitement. The repackaging of this approach has included combining ultrasound with high field MRI scanning.
Ultrasound therapy for essential tremor and potentially for Parkinson’s disease has great appeal to patients and families. It does not require a scalp incision or a hole in the skull. Additionally, the therapy has advantages over gamma knife and other radiosurgical techniques. In radiosurgery, the surgeon aims X-ray beams at the brain and destroys tissue. In ultrasound, the tissue is still destroyed, but there is an option to apply a test-lesion before placing a permanent one. Radiation therapy has another disadvantage compared to ultrasound; X-rays can lead to necrosis (dying) and uncontrolled growth of radiation-induced brain lesions. These lesions can in some cases expand uncontrollably in size, lead to delayed complications, and in one case resulted in death.
A few important points for all patients to be aware of when considering ultrasound therapy for Parkinson’s disease:
- Ultrasound therapy is not a cure for Parkinson’s disease.
- Ultrasound is not FDA approved as a therapy for Parkinson’s disease.
- The risks of ultrasound are similar to the risks of placing a conventional brain lesion (thalamotomy, subthalamotomy and pallidotomy).
- Since a destructive brain lesion can be created with both ultrasound and conventional thalamotomy, patients should be careful to not be deceived by the ultrasound marketing (particularly videos that have gone viral), which sometimes uses the word “scalpel-less.”
- Ultrasound brain surgery on both the right and left sides of the brain (bilateral) is discouraged because there is a high potential for side effects affecting cognition, swallowing and speech. This limitation can be a serious issue and a risk for Parkinson’s disease patients who may require two-sided surgery because they suffer from symptoms on both sides of their body.
- A recent study by Jeff Elias and colleagues at the University of Virginia revealed that 4/15 subjects (26.7%) had persistent sensory side effects following ultrasound therapy for essential tremor despite the use of test-lesions. One fundamental difference between ultrasound and DBS is that in DBS, re-programming of the device may in many cases can lead to resolution of symptoms.
- Microelectrode recording and physiological mapping cannot be used to refine brain targets in ultrasound therapy.
- Precision of placement of the lesion generated by an ultrasound machine has been a big hurdle for the therapy, and this area will need refinement especially as trials are conducted in Parkinson's disease patients. Patients should know that the ultrasound wave is generated outside the skull, and this creates a formidable challenge for millimeter-sized targets deep within the brain.
- One benefit of ultrasound therapy is that after the procedure there are no wires, pacemakers, or follow-up visits for programming or optimization (similar to pallidotomy, subthalamotomy or thalamotomy).
The bottom-line for patients is that ultrasound therapy is not a cure and is not actually scalpel-less (a hole is made in the brain). It may one day have a place among Parkinson’s treatments but in the meantime patients should carefully consider its potential benefits and risks.
Okun M.S. 10 Breakthrough Therapies in Parkinson’s Disease. Books4Patients, 2015.
You can find out more about NPF's National Medical Director, Dr. Michael S. Okun, by also visiting the NPF Center of Excellence, University of Florida Health Center for Movement Disorders and Neurorestoration. Dr. Okun is also the author of the Amazon #1 Parkinson's Best Seller 10 Secrets to a Happier Life and 10 Breakthrough Therapies for Parkinson's Disease. You can read more from Dr. Okun in the What's Hot in PD? archives.