In 2016, Forbes Magazine carried an article on MR-guided Focused Ultrasound (MRgFUS) for essential tremor (ET). Citing positive results from clinical trials, the article explained that “The treatment doesn’t require any implants, incisions or ionizing radiationi.” As the news spread, Parkinson’s disease (PD) patients who also suffer from tremors wondered if MRgFUS could eliminate their tremors, too.
Conventional treatments for PD tremors
PD differs from ET in many respects, and is generally accompanied by multiple symptoms that progressively worsen. In PD, the brain cells that produce a neurotransmitter called dopamine are gradually destroyed. In turn, this diminishes muscle control, leading not only to tremors that occur at rest and during voluntary movement, but also to restricted range of motion, postural impairment, loss of balance and coordination, and cognitive deficits in many cases.
Currently, conventional tremor treatments for PD patients include a range of medications (levodopa, dopamine agonists, anticholinergics, botulinum toxin, clozapine, amantadine, clonazepam, propranolol, and neurontinii). Some patients experience eventual side effects such as dyskinesia, and over time, medications generally become less effective. Surgical procedures (thalamotomy, deep brain stimulation) have helped many PD patients greatly reduce tremor, but these do not affect other PD-related impairments. Even so, patients for whom hand tremors greatly reduced their ability to function experience improved quality of life when surgical procedures are successful.
MRgFUS as an alternative to surgery
MR-guided Focused Ultrasound is a new technology that uses sonic energy (sonications) to ablate (destroy) the tiny area of the brain’s thalamus that produces tremors. Advances in MRI allow accurate mapping of the thalamus to facilitate treatment planning, and also to guide the treatment itself. Improvements in ultrasound technology allow the sonic energy to be focused at the target from many directions; when they converge upon the target, it produces the intense heat that accomplishes the ablation.
Three advantages of MRgFUS for PD tremor
MRgFUS is a noninvasive outpatient procedure. No scalpel is needed to cut skin, no drill is needed to bore a hole in the skull, and nothing is implanted in the brain. Its three main advantages for PD-related tremor are:
- No infection risk associated with surgical thalamotomy or surgical implants
- “Test” sonications to confirm precise targeting prior to full ablation
- When successful, the results are immediately evident.
A few words of caution: MRgFUS is not effective in every case. As with MRgFUS for ET, treatment will be directed to the hand in which tremor is worse, since treating both hands increases the risk of side effects. Clinical studies show that some patients have short term side effect such as headaches, dizziness or nausea but these quickly resolve. However, the effect may not be durable. Patients who have suffered with significant tremor for years may experience less effective tremor control, or gradual recurrence of tremor. Finally, MRgFUS does not cure PD, nor will it have an effect on other PD-related problems.
However, the consensus among researchers is that MRgFUS is a very promising treatment for PD-related tremor, especially as an alternative to invasive surgical procedures. If you or a loved one suffers from severe PD tremors, contact the Sperling Medical Group for more information about MRgFUS.
iKite-Powell, Jennifer. “New Ultrasound Treatment Could be an Alternative to Brain Surgery for Essential Tremors.” Forbes (Aug. 31, 2016). https://www.forbes.com/sites/jenniferhicks/2016/08/31/new-ultrasound-treatment-could-be-an-alternative-to-brain-surgery-for-essential-tremors/#3aabef9721be
iiIlana Schlesinger, Alon Sinai, and Menashe Zaaroor, “MRI-Guided Focused Ultrasound in Parkinson’s Disease: A Review,” Parkinson’s Disease, vol. 2017, Article ID 8124624, 5 pages, 2017. doi:10.1155/2017/8124624