hides / Duplass / Paul Spella / The Atlantic

Laura Bennett, a 59-year-old pediatrician in Long Island, was diagnosed with multiple sclerosis in 1997, but her symptoms consisted mostly of numbness and tingling until about six years ago. That’s when she started to have trouble walking. She went from using a cane, to a walker, to a scooter. Her knee became so stiff that flexing it was “like trying to bend a lead pipe,” she said. These days, she can only leave her home with help or in a wheelchair.

The MS also left her with debilitating fatigue. Two years ago, her neurologist asked her if she’d consider something a little unorthodox: Zapping her brain with an electrical current, from the comfort of her own home.

The treatment was part of a study performed by Leigh Charvet, a neurologist at New York University’s Langone Medical Center. It was meant to see if transcranial direct current stimulation, a brain treatment also known as tDCS, could be used remotely to relieve the brain fog and oppressive fatigue that many MS patients suffer.

Each day for two weeks, Bennett would don a headband equipped with moistened sponges and attached to what she called a “big cellphone”—a tDCS stimulator. When she was ready to start the session, a clinician would give her a four-digit code to enter on a keypad, and the current would surge through the wires and into her brain.

A diagram showing how a remote-controlled tDCS setup might work (Leigh Charvet / Frontiers in Systems Neuroscience)

In multiple sclerosis, the body’s immune system attacks the central nervous system. Many of the disease’s symptoms, which range from pain to immobility, are managed with drugs. But fatigue is the trickiest one: Other than heavy-duty stimulants like Modafinil, patients have few options. And because MS can cause debilitating pain, it’s not feasible for patients to come to the clinic regularly. That makes at-home tDCS an even more appealing option.

“For those of us who want to use neuromodulation, one of the main obstacles we face is how burdensome it is for our patients,” said Roy Hamilton, an assistant professor of neurology at the University of Pennsylvania, who was not involved in the study.*

The stimulation treatment has been shown to work with other ailments, such as depression and ADHD. It works by pulsing the brain with a low-grade electrical current—roughly equivalent to a nine-volt battery—to encourage neurons to fire. Because the voltage is so low, there’s no pain.

“You might feel a sensation of a skin burning and tingling, or some people experience it more as itching,” Charvet said. “You acclimate to that.”

Afterward, some MS patients report feeling less tired, and more clear, active, and energetic. Charvet’s results are provisional because of the small sample size. But the study, slated to be published in Neuromodulation: Technology at the Neural Interface this month, is promising. It involved 25 MS patients like Bennett who played computer games meant to boost cognition while receiving the tDCS. Meanwhile, 20 played the computer games alone. After 10 sessions, the tDCS group had greater improvements in cognition than the people who only played the games. In another experiment, which Charvet will present in April at the American Academy of Neurology meeting, the tDCS sessions also improved mood and reduced fatigue.

Charvet conducted the study with Marom Bikson, a professor of Biomedical Engineering at the City University of New York, who runs a company that designs tDCS devices. Though tinkerers have tried to rig up their own tDCS systems at home, zapping themselves at will, Charvet said there was little risk of that here since the device would only work if placed and unlocked properly.

For Bennett, the biggest hassle was “getting on the head gear. It was a pain in the butt till I got the hang of it,” she said. She would feel a mild tingling from the device while she worked on computer games that involved clicking on spots and adding up numbers. After 20 minutes, she was done.

“It definitely decreased my fatigue,” Bennett said. “As the days went along I got much more spry.” She thinks the effect lasted about two weeks afterward.

Larry Irving, a 51-year-old financial executive, used the tDCS procedure to help with his MS-induced memory and problem-solving impairments. “One of the problems I had was, in my field of finance, I was very good with numbers,” he said. But lately, “I had problems with numbers, recalling things that were important for a person in my position.”

After the treatment, “using numbers again, I felt relaxed and comfortable,” Irving said.

Hamilton praised the study for showing how tDCS could be used in a home environment, but cautioned that the ability of subjects to determine whether or not they were getting tDCS might have influenced their view of the therapy.

This at-home tDCS treatment is still very limited, but eventually it could become a treatment deployed for other ailments, such as language disorders and other cognitive problems. “There’s a backlog of people who are interested and willing to do this,” Hamilton said.

Bennett is still waiting on a surgery that might help with her movement issues, but in the meantime, she’s interested in trying the tDCS again. “I asked them, what’s the deal? Is this something you would do every morning, every month to perk yourself up?” she said. “I would be interested because it’s easy enough to do, and I had no problems with it.”


* This article originally misstated Roy Hamilton’s name as Hamilton Roy. We regret the error.

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