Before she had a piece of electronics implanted in her brain to treat her Tourette’s syndrome, Kayley Thorpe says her life could be horrifyingly predictable. During her middle school years, when her physical tics were at their worst, “I’d start each morning by punching myself in the face,” she says.
But there were also cruel surprises every day. If she walked into a grocery store, “the question was, at what point would my whole body start to jerk,” she says, “and would I collapse on the floor?"
What unified the routines and the surprises was that they were both entirely out of her control. “You’re like a passenger in your own body,” Thorpe says. “You know it looks crazy. You know other people can control their bodies, but you can’t.”
By the time she turned 19, she’d decided that an experimental brain implant was her only hope. By that point, Thorpe had been living with Tourette’s for a decade. She had tried more than a dozen different medications and many different types of therapy, but nothing reduced her physical and verbal tics enough to make her life bearable. She was using a wheelchair to navigate her daily life. “I’d really run out of options,” she says.
When her college in North Carolina told her she had to stop attending classes because she was too disruptive, she made the call to the Center for Neuromodulation at NYU Langone Medical Center. She asked to be evaluated as a candidate for deep brain stimulation.
In deep brain stimulation (DBS), a pacemaker-like implant emits steady pulses of electricity that override faulty electrical patterns in the brain. It’s already a well-established treatment for Parkinson’s disease, where the pulses regulate activity in a brain region involved in movement, thus calming tremors and other motor symptoms.
Doctors have also found success using DBS to treat neuropsychiatric problems like obsessive-compulsive disorder and depression by implanting the device in different brain regions. And because it worked for OCD patients, neurologists wondered if it would work for Tourette’s, which has a similar compulsive component.
Neurosurgeon Alon Mogilner of NYU Langone first implanted a DBS device in a Tourette’s patient in 2009, and recently published a study with long-term results from 13 Tourette’s patients. The study found that, on average, the patients’ tic severity decreased by 50 percent, and all reported that the improvements to their quality of life made the surgery well worth it. Mogilner’s initial patient is still doing well, he says: “She’s now 24, and an ICU nurse at a busy hospital.”
For Tourette’s, Mogilner implants the DBS device in the thalamus, which he describes as “the Grand Central Station of the brain” because it serves as a junction that relays signals between the peripheral nervous system and the cerebral cortex. In Tourette’s patients, there’s abnormal activity in a part called the medial thalamus. Mogilner places the DBS device in that spot, where its electrical pulses prevent faulty signals from going out to other parts of the brain.
Mogilner says Tourette’s is a disease that involves mutliple brain regions, and that researchers haven’t found a single distinct location that triggers the tics. So he speaks of Tourette’s as resulting from a disfunctioning circuit in the brain, which can be altered by placing the DBS device in the junction region.
The current DBS treatment doesn’t shut off patients’ tics entirely. “I wish people were 100 percent cured,” says Mogilner. Instead, patients have fewer tics, and less severe ones. “When people have stressful times in their lives, their tics may get worse for a day or two,” he says.
Thorpe had her DBS device implanted in June 2014. After an overnight stay in the hospital and two weeks of recovery in a New York City hotel room, Thorpe returned to the clinic for the doctors to turn on the DBS device. With a remote control, the neurologists activated the device’s eight electrodes and ran through different patterns of stimulation. They were looking for a combination that would likely be effective and wouldn’t cause side effects. “When they activated the lowest contact on one side I got really dizzy, like I was on a carousel,” Thorpe remembers.
Back home in North Carolina, Thorpe gradually turned up the voltage on the device, the way you would gradually increase the dose of a new medication. And she gradually got better. “For me, it wasn’t immediate,” she says. “It took a while for the dramatic effects.” The doctors had instructed her to take it easy for six weeks, but it was hard for her to be sedentary when she felt her motor tics lessening, giving her a renewed physical freedom. “When I was finally cleared to be active again, I got on my bike and just started going,” she says.
It’s been three years now since Thorpe’s surgery freed her from her wheelchair. She says she still has to watch her stress levels to keep her tics under control. “I can still have fall-over attacks, I can still have screaming fits,” she says. “But they’re much less frequent—and they’re never as bad as pre-DBS.”
She’s also been able to return to college. After her recovery, Thorpe worked at Target for a year, then started classes at community college. This fall, she’s going to the University of North Carolina at Chapel Hill. She plans to major in psychology and continue on to a PhD.
DBS for Tourette’s may well remain an experimental treatment, because it’s only appropriate for a subset of patients who don’t respond to medication or therapy. Neurosurgeon Mogilner explains that it would be difficult and expensive to organize the large clinical trial required for full FDA approval. However, it could receive a limited type of FDA approval called a humanitarian device exemption, which the agency can award when a device can benefit a small number of patients who have no other recourse. That’s the kind of approval that DBS devices gained for treating OCD.[shortcode ieee-pullquote quote=""Some Tourette's patients become recluses because they can't interact. DBS is hope for people when nothing else seems to work."" float="right" expand=1]
Mogilner says DBS is particularly crucial for Tourette’s patients, because the disorder strikes young people and prevents them from going to school and joining the workforce. “You have people who become recluses because they can’t interact,” he says. “DBS is hope for people when nothing else sems to work.”
For Thorpe, DBS has given her new confidence. She’s no longer a passenger in her body, worrying about what it will do next. She no longer worries about falling over in a grocery store, or dreads the possibility that she’ll yell a racial epithet in the middle of a crowd.
Now she’s the driver—literally. Before surgery, Thorpe couldn’t drive a car, because she knew she could tic at any moment and jerk the stering wheel. “Now I have this incredible freedom: I drove all the way from North Carolina to New Jersey,” she says. “That was unthinkable pre-surgery.”
Eliza Strickland is a senior editor at IEEE Spectrum, where she covers AI, biomedical engineering, and other topics. She holds a master’s degree in journalism from Columbia University.