According to the International Essential Tremor Foundation, Deep Brain Stimulation (DBS) is the most common surgical treatment for hand tremors that don’t respond to medication. It has published outcomes showing that most tremor patients still experience improvement 7-10 years later.i
A noninvasive alternative to DBS surgery is MRI-guided FUS (MRgFUS). Granted, it does not yet have the published longevity data since it was just approved by the FDA in July, 2016. However, it is rapidly gaining traction among physicians and patients. In large measure, this is due to the reduced risk of side effects, and the relatively easy, comfortable patient experience.
Compare the procedures
DBS involves two surgical phases, one involving brain penetration, and the second (either the same day or several days later) involving the chest area. For phase one, the patient’s head is immobilized in a frame, and imaging (MRI or CT) is used to map the small area of the thalamus where tiny electrodes on wire leads will be implanted. A small area of the scalp is shaved and anesthetized, and a hole is drilled through the skull. Since there are no nerves in the brain, the implantation is painless. Before completing the surgery, the electrodes are briefly activated to test how effective the placement is (control of tremors) and to check for side effects. This phase of surgery ends when the doctor is satisfied. In phase two, a type of battery pack is implanted under the skin of the chest. A wire from the pack is tunneled under the skin of the neck, and connected to the ends of the brain electrode leads. After the brain surgery, the patient usually spends a night in the hospital, and slowly eases back into daily activities. About a month later, the battery pack will be switched on, and programmed for maximum tremor control.
MRgFUS is a single, outpatient treatment. In this case, the patient’s entire head is shaved. As with DBS, the patient’s head is stabilized within a helmet-like device that will transmit hundreds of ultrasound beams aimed at the VIM nucleus of the thalamus. First, advanced MRI is used to identify the treatment target, and to plan the treatment itself. When treatment begins, a series of “sonications” or bursts of ultrasound beams pass harmlessly through the skin, skull and brain until they converge (meet or intersect) at the target. This generates a tiny point of head strong enough to deaden the area that transmits the malfunctioning motor control signals that cause tremor. There is no pain, and patients are fully awake. The treatment is monitored by MRI, and the doctor can check how effective it is with the same type of hand test used in DBS. Success is immediately apparent, and when the treatment is over, patients can rest a bit then go home.
Compare side effect risksii
|Brain bleeding:||0.5 – 2.0% risk||0% risk|
|Infection:||1-3% risk||0% risk|
|Problems with lead wires||1-3% risk||0% risk|
|Seizures:||<5% risk||0% risk|
|Device Malfunction needing surgery:||1-3% risk||0% risk|
|Future Maintenance||Worn out battery pack needs surgical replacement||No battery pack needed|
|Short term change in sensation or gait||Rarely reported||Short term change in sensation or gait reported up to 38%|
Compare patient experienceiii
|Patient is awake||Patient is awake|
|Patient’s head immobilized||Patient’s head immobilized|
|Imaging plans and guides treatment||Imaging plans and guides treatment|
|Patient response monitored by tests||Patient response monitored by tests|
|One-night hospitalization||Outpatient, home the same day|
|Down time needed to recover||Return to usual activities in 24 hours|
|Results not known until battery pack is activated (a few weeks – 1 month)||Results known immediately|
In reviewing the above information, it is easy to understand why tremor patients, if given a choice, prefer the noninvasive MRgFUS over the neurosurgical implantation of electrodes and battery pack. The Sperling Medical Group is pleased to offer the Neuravive MRgFUS procedure for the control of tremors due to Essential Tremor of Parkinson’s disease. For more information, contact us.
iiFishman, P. Thalamotomy for essential tremor: FDA approval brings brain treatment with FUS to the clinic. J Ther Ultrasound. 2017; 5: 19.