Researchers at the University of Washington (UW) and its Centre for Sensorimotor Neural Engineering (CSNE) have developed a new approach to using deep brain stimulation (DBS) for the treatment of essential tremor.
DBS involves implanting electrodes deep in the brain, and the wire is then passed under the skin to a battery placed in the chest to provide electrical stimulation to address the disorder’s symptoms.
The implanted devices provide continuous stimulation even in cases when the patients do not require it, leading to battery wastage.
UW researchers combined electrodes on top of the brain with a deep brain electrode to enable stimulation only when required and extend the battery life.
The new method is expected to aid in the development of fully-implanted, closed-loop deep brain stimulators that can be controlled by the thoughts or movements of patients with disorders such as essential tremor or Parkinson’s disease.
UW electrical engineering professor Howard Chizeck said: “We’re saving about half of the battery power based on our subjects so far, which was one of our main motivations.
“But even more interesting are some early indications that suggest our closed-loop system results in better patient performance, with less tremor, better control of their hands and fewer side effects.”
During the research, Medtronic’s Activa PC+S Deep Brain Stimulation system was used to test new methods for activating the device, for which they obtained investigational device exemption from the US Food and Drug Administration (FDA).
In addition to the delivery of electrical stimulation, the medical device manufacturer’s system is said to sense and respond to electrical signals generated by the brain.
Alongside the system, the researchers also implanted a small strip of electrodes on top of the patient’s motor cortex, which is a part of the brain that controls movement.
They further developed machine learning algorithms for decoding the brain’s neural signals and correlating them with essential tremor symptoms.
Upon analysis, the ability of the new system to quieten symptoms was found to be comparable to the standard system, while showing better energy savings.
Image: CSNE team member performing tests on Medtronic’s brain stimulator. Photo: courtesy of Mark Stone/University of Washington.