There is still no cure for Parkinson’s disease, but the U.S. Food and Drug Administration (FDA) approved a new deep brain stimulator that could benefit patients with the motor condition.On Feb 24, the FDA approved Medtronic’s BrainSense Adaptive deep brain stimulation, a device that surgeons implant in patients’ chests with electrodes connecting to the brain. The system is programmed to respond to and manage abnormal brain signals that contribute to involuntary muscle movements in Parkinson’s, which previous deep brain stimulation systems could not do. The device represents the most personalized and responsive deep brain stimulator for the condition.[time-brightcove not-tgx=”true”]“A deep brain stimulator is a brain pacemaker: similar to a cardiac pacemaker, except you insert electrodes in the brain to stimulate brain neurons,” says Dr. Helen Bronte-Stewart, professor of neurology, neurological sciences, and neurosurgery at Stanford University. Bronte-Stewart helped design the international, multi-center trial to test the device.Here’s what to know about deep brain stimulation for Parkinson’s disease. Refining an “always on” deviceDoctors have offered deep brain stimulation to Parkinson’s patients since 2002. But until now, devices have only provided continuous stimulation—not the dynamic and responsive activation that the current device does—and followed a one-size-fits-all model that was always “on” to activate the parts of the brain involved in motor function.Continuous stimulation causes a treatment imbalance for patients who are often also taking medications to control their involuntary muscle movements. Soon after a patient takes a dose, for example, the combination of the medications and deep brain stimulation could lead to overtreatment of their symptoms; once the medication wears off and before they take their next dose, they would likely be undertreated and have more severe tremors or abnormal muscle movements. Read More: A Potential Parkinson’s Treatment Has Promising ResultsThat’s because deep brain stimulation and Parkinson’s medications all target a specific arrhythmia in what experts call the beta pattern. But until recently, doctors didn’t understand much about the beta rhythm in the brains of Parkinson’s patients, including how it fluctuates over the course of a day or depending on what patients are doing. Recent studies have shown, for example, that arrhythmia in beta signaling decreases when people sleep.The previous, continuous devices simply stimulate the signals for motor neurons, regardless of whether someone needs the stimulation at any given time or not. It’s analogous to putting someone on medication for high blood pressure without measuring the fluctuations in their blood pressure, says Bronte-Stewart. “It was on all the time and was the same for every patient, so it didn’t sense a person’s specific arrhythmia and didn’t adapt,” she says.A long road to a new approachThe new adaptive device is the result of decades of research into reading changes in brain signals relevant to Parkinson’s disease, and developing algorithms that can respond to those changes in real time. “Like cardiac pacing, we’ve written an algorithm that responds to when patients take medication, and modulates the beta rhythm to the stable range and stops it from going too high or too low,” says Bronte-Stewart. “Brain pacemakers are finally catching up to cardiac pacemakers.”The advance also required finding ways to take the same measurements that doctors could collect in the operating room—when they would implant electrodes in the brain—but without repeated invasive procedures. Learning more about which signals and networks to target in Parkinson’s was necessary. “It was very important to spend years determining which signals were relevant to motor problems,” says Bronte-Stewart. “We had a way of measuring movement in humans in our labs that not many had.”Then came the task of encapsulating all of that activity in an implantable device that could safely live in the brain for years at a time, collect information, and adjust to nerve signals in real time. Data collected from patients with the original continuous devices provided a foundation for the new adaptive model. Continuous deep brain stimulation “really enabled us to get access to these patients’ brains that we wouldn’t have been able to access any other way,” says Scott Stanslaski, senior distinguished engineer at Medtronic who has been working on implantable devices for three decades. Stanslaski says those early devices made it possible to develop brain-sensing technology to read the signals zapping around the brain, and isolate which ones were critical for Parkinson’s. “There were a lot of epic fails in the early phases to figure out the sensing technology,” he says.A “life-changing benefit” for patientsJohn Lipp was diagnosed with Parkinson’s just shy of his 50th birthday, after he noticed that his right hand and foot would involuntarily clench, making it difficult for him to walk without tripping. He took the standard Parkinson’s medications, which are the first line of treatment, but experienced severe anxiety and had to switch therapies. As his symptoms worsened, he and his doctors discussed deep brain stimulation, which is generally a last resort intervention since it involves risky brain surgery.Lipp decided to receive the adaptive device, which Medtronic was still studying in research trials in 2021. He joined the trial Bronte-Steward was running. “I noticed a change almost immediately,” Lipp says. “My most problematic symptom was dystonia, or muscle cramping, which was both painful at times and debilitating.” But after surgery, “my dystonia pretty much went away. That, to me, is the most significant, life-changing benefit.”The new device has also allowed him to reduce his Parkinson’s medications from 14 or 15 a day to four, he says.Read More: Michael J. Fox: Chasing Parkinson’s TreatmentsLipp says the device has quelled almost all of his symptoms. The only time he’s reminded of them is during his regular visits to Bronte-Stewart for check-ups, when the doctors briefly turn the device off. “My body kind of collapses,” he says. “I feel a change in my muscle tone, and my ability to sit up straight; it’s like I’m pulled into my center of gravity. So I know it’s working.”Bronte-Stewart stresses that the device does not slow the progression of Parkinson’s, but it can help patients to live more comfortably with their symptoms. For now, the device Lipp and others will receive can remain in their brains for about 15 years, and doctors can replace the battery as needed in an outpatient procedure. Lipp is also reassured that having the device won’t exclude him from taking advantage of any new treatment or potential cure for the disease, should these be developed. “Let’s say some miracle cure comes along; I can always have the device removed. That offers me a sense of security,” he says.Lipp credits the advice with making it possible for him to travel with his husband and even run marathons. He ran the New York City Marathon last year, and plans to do it again this year. Before getting the device, “I thought my running days were over because of my rapidly developing symptoms,” he says. “The fact that I can still do [marathons] is great.”