Recent experiments have begun individualizing brain stimulation for depression, obsessive compulsive disorder and chronic pain. While much more research is needed — along with ways to make the approaches pragmatic and affordable — several experts predicted that some versions of brain pacemakers could be available within five or 10 years.
“I do think this points the way that indeed personalized, individualized stimulation is the wave of the future,” said Dr. Jaimie Henderson, a professor of neurosurgery at Stanford who was not involved in the study.
Deep brain stimulation has been used for years for Parkinson’s. It’s typically introduced when patients have achieved what benefit they can from medications containing levodopa, a drug that combats the deficit of the hormone dopamine that drives Parkinson’s disease.
Under conventional deep brain stimulation, patients receive a constant level of electrical pulses. While it helps most patients, many eventually reach a plateau or, because the therapy does not adjust to a patient’s experience, the stimulation may be too much or too little and lead to drastic swings between periods of rigidity and unbridled motion.
“It’s not like we’ve like maximized, optimized, finalized our abilities to treat Parkinson’s patients,” Dr. Sheth said.
In recent years, neuroscientists have identified brain signals that correspond to phases of stiffness, called bradykinesia, and phases of uncontrolled movement, called dyskinesia. In the new study, researchers used methods derived from A.I. to devise a personalized algorithm for each patient and a way to detect and respond to brain activity as the patient’s symptoms fluctuated.
“The brain changes in its needs moment to moment, hour to hour, week to week,” said Dr. Philip Starr, a professor of neurological surgery at the University of California, San Francisco, and a senior author of the study who has worked on deep brain stimulation for decades. “So it’s been a dream to make these stimulators self-regulating.”
Dr. Simon Little, an associate professor of neurology at U.C.S.F. who led the study along with Dr. Starr, said that electrodes implanted in patients’ brains recorded signals from populations of neurons, not individual brain cells.