01 Mar 2017

How Deep Brain Stimulation Could Change Medicine

Already employed to treat neurological-based movement disorders, the procedure could soon be used on everything from depression to addiction.
by Janelle Nanos


Illustration by Jon Krause

Roger Frisch, a concert violinist with the Minnesota Orchestra, sees his instrument as an extension of himself—each time he pulls the bow across its strings, the vibrations seem to echo through him. So in June 2009, when Frisch began to feel tremors in his bow whenever he practiced, he immediately knew that something in his body was out of sync. He was diagnosed with essential tremor, a neurological disorder that causes involuntary and rhythmic shaking of the arms or hands. For someone whose livelihood depends on a meticulous attention to tone quality, it was nothing short of a nightmare.

After exhausting other treatment options, Frisch chose a radical alternative: having tiny, needle-like electrodes placed inside his brain.

Those electrodes are part of a device called Harmoni, a deep brain stimulation and measurement tool being developed at Minnesota’s Mayo Clinic. Kevin Bennet (MBA 1980) chairs the hospital’s 102-year-old engineering department, where some of the first machines designed to keep patients alive during open-heart surgery were developed. Today, Bennet oversees a team of 67 programmers, technologists, and engineers to tweak preexisting medical instruments or develop entirely new medical devices.

The general deep brain stimulation procedure is now established practice: For over a decade, neurosurgeons have placed electrodes in the brains of patients suffering from neurological-based movement disorders. Those electrodes deliver pulses that spur the release of neurotransmitters, the chemicals that stimulate the neurons that carry messages throughout the brain.

This targeted approach gives Bennet hope that Harmoni can benefit not only people suffering from movement disorders, but also a whole class of psychiatric patients.

This targeted approach gives Bennet hope that Harmoni can benefit not only people suffering from movement disorders, but also a whole class of psychiatric patients.

But working under Bennet and his collaborator, neurosurgeon Kendall Lee, a team of researchers and engineers at Mayo’s Neural Engineering Laboratory began to make dramatic improvements to the technology behind the treatment. Instead of requiring constant tweaking like a typical deep brain stimulation device, Harmoni’s sensors work to keep the brain in tune automatically, recalibrating whenever the cells stop communicating appropriately to maximize the therapeutic effects. The electrodes are placed inside the brain at the precise spot where the issue originates and communicate to a wireless monitor that tracks the neurotransmitter changes to make real-time adjustments in the brain stimulation.

This kind of targeted approach gives Bennet hope that Harmoni can benefit not only people suffering from movement disorders, but also a whole class of psychiatric patients who, until now, had few options beyond prescription drugs to help lessen the effects of their disorders. “If you’re not feeling well, pharmaceuticals are the primary choice,” says Bennet. “But in most cases they’re not really a miracle” but a temporary reprieve. Bennet notes that while millions of patients suffer from psychiatric disorders, many don’t know that deep brain stimulation is a treatment option. He hopes that a device like Harmoni could provide drug-free therapy for people suffering from illnesses like depression, addiction, obsessive-compulsive disorder, or Tourette syndrome, with its exacting approach alleviating concerns about side effects from medications or drug dependency.

Frisch’s ailment was a perfect example of the procedure’s precision: There were a few cells in his brain that were responding in unison—the effect akin to a record skipping, playing the same note over and over again. Bennet and his colleagues needed a way to resume the melody.

There was only one hitch: The patient needs to be awake during the surgery to ensure that the electrode is placed in the exact area being affected. So on the day Frisch was in surgery, he played a special violin that Bennet’s engineering team had created, with a bow that could detect his tremors. In what was likely the most bizarre concert Frisch has ever played, he performed in the operating room as doctors tinkered inside his brain. All the while, Bennet and his team monitored the tremors as neurosurgeon Lee inserted the electrodes, making sure that each found its target. The procedure was a success; Frisch was practicing on his violin the day after the surgery.

While Bennet admits that researchers are only now beginning to understand how such neuromodulation therapies work within our brains, he also notes that Mayo aims to continue to test Harmoni’s efficacy on issues like spinal cord injuries, dementia, and Alzheimer’s disease. “We’re in discovery mode,” he says. He doesn’t see electrical treatment techniques—also known as electroceuticals—pushing traditional pharmaceuticals out of the market in the foreseeable future. “But I do think we’ll soon see a world where electroceuticals will be a viable solution.”

Featured Alumni

Featured Alumni

Class of MBA 1980, Section H

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