Imagine you have a big problem you want solved. You find out there are two solutions, A and B, either of which will solve the problem to your satisfaction. You might think, “Well, if A and B work equally well, why not just flip a coin?” But upon further examination, you discover that Solution B comes with an appealing bonus. How nice! That tips the scales, and you choose B.
Two neurosurgical procedures for tremor treatment
The two most common movement disorders that cause tremors of the hands or other parts of the body are essential tremor (ET) and Parkinson’s disease (PD). While they are separate conditions, the first line of treatment for either of them is medication. However, medication is generally not effective over the long term for both conditions. If tremors progress to the point of impairment, patients may be offered a neurosurgical intervention.
There are two types of neurosurgical procedures to control tremors: deep brain stimulation (DBS) and Focused Ultrasound (FUS).
- DBS uses implanted electrodes connected by wires to a battery pack in the chest. The battery pack generates an electric current to activate the electrodes, which stimulate a very small area in the brain. The electrodes are inserted via a hole drilled in the skull. The current can be adjusted over time for optimum control. The surgery can be reversed if needed, though tremors will then return. Risks include infection, dislocation of electrodes, and a slight risk of stroke.
- FUS uses noninvasive ultrasound to permanently ablate (destroy) a tiny component of the brain’s tremor pathway. The ablation is accomplished by heat created precisely where the beams intersect at the target. This immediately blocks transmission of the abnormal signals that are causing tremors while preserving all normal movement. (NOTE: An earlier method of lesion surgery called radiofrequency thalamotomy used a physical probe inserted through the skull into the target to create heat. However, with the advent of FUS, radiofrequency is rarely done.)
New study reveals better quality of life with FUS
Research has shown that both DBS and FUS are equally effective in reducing tremors. Some earlier studies suggested that DBS offered greater functional improvement, but as noninvasive FUS is increasingly used and refined, that distinction appears to be diminishing.
Now, a new study reveals a distinction in favor of FUS: better quality of life after treatment. Altinel, et al. (2018)i conducted a review of published literature to compare the effectiveness, improved function, and quality of life for those with ET, PD and multiple sclerosis whose tremors were treated with either DBS or lesion surgery. 15 published randomized clinical trials were analyzed:
A total of 1, 508 patients (mean age range, 48.4 to 70.8) were included, and in addition to the 13 studies involving only Parkinson’s patients, one study looked at people with Parkinson’s, ET and MS, while the remaining study was in people with severe ET … Four of the 15 trials — involving 125 patients — directly compared DBS to LS. The others compared either LS or DBS with controls.ii
Most of the data on lesion surgery (ablation) was drawn from radiofrequency thalamotomy which was more common before FUS was developed. However, two of the more recent lesion surgery papers involved FUS ablation. The authors used these two papers to run a separate subgroup analysis comparing DBS with FUS on tremor control, improved function, and quality of life after treatment.
This subgroup analysis “…revealed that [FUS] was associated with a significant improvement in quality of life compared to DNS, although changes in tremor severity were similar.”iii
Benefits of FUS
Two solutions for tremors, DBS and FUS, are equally effective, but one of the offers better quality of life. It is certainly not difficult to imagine the “bonus” that comes with FUS: an outpatient, noninvasive, effective end to tremors, as compared with a two-part neurosurgery that requires an overnight hospital stay, hardware implants, possible future adjustments, battery replacement, etc.
However, as with all medical changes, more research is needed, especially apples-to-apples studies to compare DBS with FUS. After all, FUS is a relatively recent innovation compared with DBS. Still, the authors wrote, “Policy makers, healthcare providers, and patients could therefore consider focused-ultrasound [LS] as a potential choice for tremor control, based on currently available evidence.”iv
Sperling Neurosurgery Associates is proud to be at the forefront of Focused Ultrasound, an elegant noninvasive solution for ET tremors that preserves quality of life. Contact us to find out more about its benefits.
iAltinel Y, Alkhalfan F, Qiao N, Velimirovic M. Outcomes in Lesion Surgery versus Deep Brain Stimulation in Patients with Tremor: A Systematic Review and Meta-analysis. World Neurosurg. 2018 Nov 27.
iiLopes, JM. “Lesion surgery can improve tremors and improve life quality, study says.” Parkinson’s News Today. Dec. 5, 2018. https://parkinsonsnewstoday.com/2018/12/05/lesion-surgery-with-focused-ultrasound-treat-tremors-and-improve-quality-of-life-study-finds/