Brain zaps may help curb tics of Tourette syndrome

January 16, 2018 by Dennis Thompson, Healthday Reporter

Electric zaps can help rewire the brains of Tourette syndrome patients, effectively reducing their uncontrollable vocal and motor tics, a new study shows.

The procedure, called deep brain stimulation (DBS), improved tic severity by nearly half in 171 with uncontrolled Tourette symptoms at 31 hospitals in 10 countries.

"That's an impressive number," said senior researcher Dr. Michael Okun, chair of neurology and co-director of the Movement Disorders Center at the University of Florida's College of Medicine. "To get that much improvement in these symptoms is difficult when using medication or behavioral therapy."

With DBS, brain surgeons run thin electric leads to specific regions of the basal ganglia, a cluster of nerves in the brain related to motor control and behavior, Okun explained.

Doctors then apply electricity to the brain circuits they've most closely linked to Tourette, to try to control the patient's tics.

"We're eavesdropping on the brain and trying to find the circuit responsible for adversely affecting the patient's quality of life," Okun said. "We then introduce electricity into the brain to change the way these circuits function."

However, the procedure still needs more work. More than a third of patients experienced adverse events, most often slurred speech or a pins-and-needles sensation.

These side effects occur when electricity meant for one brain circuit unintentionally spreads to other nearby nerves, Okun explained.

"The circuits we want to drive or suppress are frequently next to circuits we don't want to disturb," Okun said. Future research will focus on improvements to electrical leads so they will more precisely deliver current to targeted brain circuits, he said.

Tourette patients are typically treated using medications and speech or behavioral therapy. An estimated 300,000 U.S. children—about 1 out of every 160—are affected by Tourette, according to the Tourette Association of America.

Another option for severe Tourette cases is , which also is used to treat many other motor disorders, including Parkinson's disease, essential tremor and multiple sclerosis, experts said.

Researchers wanted a better idea of whether DBS is effective in treating severe cases of uncontrolled Tourette, which can cause so strong that people end up hurting themselves.

Unfortunately, even top institutions tend to use DBS on only one or two patients each year, Okun said.

To come up with a comprehensive review, an international network of hospitals began submitting data on Tourette syndrome patients treated with DBS, to create a public database and registry that would help determine the pros and cons of the procedure, Okun said.

This latest study focused on the one-year follow-up results from 171 patients who underwent DBS implantation between 2012 and 2016, after other means of treating their Tourette had failed.

Average tic severity in these patients improved by 45 percent within one year of DBS implantation, the data shows.

"From this study, we see it could have some promise for those with severe Tourette syndrome that haven't been responsive to other treatments," said Diana Shineman, vice president of research and medical programs at the Tourette Association of America.

But more than 35 percent of patients treated with DBS developed adverse side effects. The most common were a pins-and-needles sensation (8 percent) and slurred speech (6 percent). Two patients suffered from bleeding in their brain, and four patients developed an infection from their surgery.

"It is surgery and we do know there are some serious side effects, and those should not be taken lightly," Shineman said.

The good news is that the pins-and-needles sensation (called paresthesia) and the slurred speech (dysarthria) were reversible.

"In almost all the cases, the effects resolve by changing the program or turning the device off," Okun said.

To further reduce these side effects, future efforts will try to more precisely identify the nerves that cause Tourette symptoms, and then target them with better technology that more accurately monitors signals and delivers electrical impulses, Okun said.

Researchers are also developing a "smart" DBS that will only discharge current when it's needed, rather than maintain a continued electrical charge, Okun said.

"We're beginning to move past some of the earlier notions of how electricity was given, where we just put the lead in and turned it on, and set it to the best risk/benefit that we can in the best region," Okun said. "Now we're beginning to refine that with better leads and better technologies."

The study was published online Jan. 16 in the journal JAMA Neurology.

Explore further: New brain stimulation target identified for Tourette syndrome

More information: Daniel Martinez-Ramirez et al. Efficacy and Safety of Deep Brain Stimulation in Tourette Syndrome, JAMA Neurology (2018). DOI: 10.1001/jamaneurol.2017.4317

For more on Tourette syndrome, visit Tourette Association of America.

Related Stories

New brain stimulation target identified for Tourette syndrome

March 4, 2016
Specifically targeted deep-brain stimulation improves symptoms in patients with severe Tourette, a study reports in the current issue of Biological Psychiatry.

Deep brain stimulation powerful in treating Tourette's

August 16, 2012
Ten out of 11 patients with severe Tourette’s Syndrome have reported improvement after receiving deep brain stimulation surgery, according to University of New South Wales research published in the American Journal of ...

Deep brain stimulation decreases tics in young adults with severe Tourette syndrome

April 7, 2017
A surgical technique that sends electrical impulses to a specific area of the brain reduces the "tics," or involuntary movements and vocal outbursts, experienced by young adults with severe cases of Tourette syndrome, according ...

Tourette-like tics vanish in mice treated with histamine

June 6, 2017
Yale scientists produced increased grooming behavior in mice that may model tics in Tourette syndrome and discovered these behaviors vanish when histamine—a neurotransmitter most commonly associated with allergies—is ...

Researchers find clue to cause of tics in Tourette syndrome

January 6, 2015
The tics seen in Tourette syndrome may be caused by the loss of specific neurons in the brain, a Yale University study has demonstrated.

Brain's role in Tourette tics simulated in new computational model

March 30, 2017
A new computer-based brain simulation shows that motor tics in Tourette syndrome may arise from interactions between multiple areas of the brain, rather than a single malfunctioning area, according to a study published in ...

Recommended for you

Precision neuroengineering enables reproduction of complex brain-like functions in vitro

November 14, 2018
One of the most important and surprising traits of the brain is its ability to dynamically reconfigure the connections to process and respond properly to stimuli. Researchers from Tohoku University (Sendai, Japan) and the ...

New brain imaging research shows that when we expect something to hurt it does, even if the stimulus isn't so painful

November 14, 2018
Expect a shot to hurt and it probably will, even if the needle poke isn't really so painful. Brace for a second shot and you'll likely flinch again, even though—second time around—you should know better.

A 15-minute scan could help diagnose brain damage in newborns

November 14, 2018
A 15-minute scan could help diagnose brain damage in babies up to two years earlier than current methods.

New clues to the origin and progression of multiple sclerosis

November 13, 2018
Mapping of a certain group of cells, known as oligodendrocytes, in the central nervous system of a mouse model of multiple sclerosis (MS), shows that they might have a significant role in the development of the disease. The ...

Mutations, CRISPR, and the biology behind movement disorders

November 12, 2018
Scientists at the RIKEN Center for Brain Science (CBS) in Japan have discovered how mutations related to a group of movement disorders produce their effects. Published in Proceedings of the National Academy of Sciences, the ...

In live brain function, researchers are finally seeing red

November 12, 2018
For years, green has been the most reliable hue for live brain imaging, but after using a new high-throughput screening method, researchers at the John B. Pierce Laboratory and the Yale School of Medicine, together with collaborators ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.