Thalamic deep brain stimulation (DBS), a surgical technique that sends electrical impulses to the brain’s medial thalamus, has been shown to reduce tics, or involuntary movements and vocal outbursts, in severe cases of Tourette syndrome, according to a new study at New York University (NYU) Langone Medical Center.
DBS has been used to treat other neurological conditions that cannot be sufficiently controlled by medication, including Parkinson’s disease, essential tremor, dystonia, and epilepsy.
The findings, published in the Journal of Neurosurgery, add to the growing body of evidence supporting DBS as a safe and effective treatment for severe cases of Tourette syndrome and may ultimately lead to approval by the U.S. Food and Drug Administration.
“Our study shows that deep brain stimulation is a safe, effective treatment for young adults with severe Tourette syndrome that cannot be managed with current therapies,” said Alon Mogilner, M.D., Ph.D., an associate professor in the departments of neurosurgery and anesthesiology, at NYU Langone, and director of its Center for Neuromodulation.
“This treatment has the potential to improve the quality of life for patients who are debilitated through their teenage years and young adulthood.”
Tourette syndrome is a disorder that typically begins in childhood, and although many patients improve as they get older, some patients’ symptoms become so severe that they become socially isolated and unable to work or attend school.
Mogilner and his colleague, Michael H. Pourfar, M.D., an assistant professor in the departments of neurosurgery and neurology and co-director of the Center for Neuromodulation, have pioneered the largest U.S. case series of thalamic DBS to treat severe Tourette syndrome in young adults. Worldwide, only an estimated 160 cases have been performed to date.
In a multi-step procedure, surgeons insert two electrodes into a region of the brain called the medial thalamus, part of the brain circuit that functions abnormally in Tourette’s. During a second surgery the following day or a few days later, a pacemaker-like device called a neurostimulator is connected to the electrodes to emit electrical impulses into the medial thalamus. These impulses are adjusted during a series of follow-up outpatient visits to find the combination of settings that best control symptoms.
In the study, the NYU Langone team followed 13 patients with at least six months of follow-up visits. Study participants ranged in age from 16 years to 33 years. To determine the effectiveness of the procedure, the researchers measured the severity of tics before and after surgery using the Yale Global Tic Severity Scale (YGTSS).
They found that the severity of tics decreased on average 37 percent from the time of the procedure to the first follow-up visit. At their latest visit, patients’ tic scores decreased by an average of 50 percent.
Equally significant, all patients reported in a survey six months after surgery that their symptoms improved either “much” or “very much,” and all said they would have the surgery again — even those who had complications or experienced relatively less pronounced results.
“The survey represents an important aspect of the study,” said Pourfar, “because the YGTSS, though a validated scale, may not fully capture the impact of DBS on quality of life for a person with Tourette syndrome.”
Source: NYU Langone Medical Center