Approximately 10 million people in the United States have essential tremor (ET), which eventually can interfere with daily activities such as eating, drinking and writing. Yet, most people with ET are never offered a therapy that was FDA approved in 1997.
At the University of Michigan, a program called STIM—Surgical Therapies Improving Movement—is changing the lives of people with ET using this very treatment, called deep brain stimulation (DBS).
“I think most people know DBS is a really good and effective therapy for Parkinson’s because two-thirds of our referrals are for Parkinson’s. But fewer people know how good it is for essential tremor. And ET is a much more common disease than Parkinson’s,” says Kelvin Chou, M.D., co-director of STIM and co-director of the Movement Disorders Clinic.
Approximately 10 million people have ET compared with approximately 1 million who have Parkinson’s.
“There’s an incredible unmet clinical need for this therapy. The major barrier to patients getting this quality-of-life-improving therapy is essentially a lack of awareness. That’s why we’re very interested in helping to educate providers and patients about the risks and benefits of DBS for ET,” says Parag Patil, M.D., Ph.D., an assistant professor in U-M’s departments of Neurosurgery, Neurology, Biomedical Engineering and Anesthesiology.
The STIM program treats essential tremor and Parkinson’s primarily, but DBS is also effective for patients with dystonia and a few other neurological disorders.
A DBS device is similar to a pacemaker for the heart, but instead of having electrodes (or electrical wires) implanted in the heart, the electrodes are placed into the thalamus portion of brain. The electrodes carry electrical signals to specific brain locations. These electrical signals cause the brain cells around the DBS electrode to change their activity. By changing the activity of brain cells, DBS can reduce the symptoms of many neurological disorders, depending on where the electrodes are placed.
DBS is not a cure for the disease but a way to manage it more effectively. It can offer many benefits, including the need to take less medication and therefore experience fewer medication side effects.
Before patients are considered for DBS surgery, they are evaluated by the multidisciplinary STIM team, which has extensive training in DBS. The team includes a neurosurgeon, neurologist, clinical neuropsychologist, speech pathologist, social worker and other team members who ensure that the patient and their family understand the procedure and discuss expectations and concerns.
“In our program, a third of patients who are referred for DBS just need to have their medication adjusted. Another third go through the evaluation process, are offered the surgery and choose to defer. They’re not quite ready. So, that leaves one-third who actually have the surgery. And that’s fine, because for us, the emphasis is education, not just operating on people,” Patil says.