Deep brain stimulation (DBS) first emerged in the 1960s and 1970s as a possible treatment for pain management, but clinical trials showed only modest results. Then, in the 1980s, DBS was used to successfully treat symptoms of Parkinson’s disease, which opened the door to using it for other movement disorders.
The U.S. Food and Drug Administration approved DBS for Parkinson’s and essential tremor in 1997, for dystonia in 2003, and for epilepsy in 2018. These successes spurred interest in using DBS to also treat psychiatric conditions, like depression and obsessive-compulsive disorder. DBS was approved to treat the latter in 2018, but its potential for treating severe cases of depression is still being debated. A few ongoing pilot studies are also testing DBS in people with anorexia and obesity. Despite decades of research and application, exactly why DBS works remains a bit of a mystery.
Now, as scientists unravel the brain mechanisms that drive addiction, some think DBS could help reduce cravings for alcohol and drugs as well. In addition to the trial for alcohol addiction in Canada, researchers at West Virginia University are investigating DBS for opioid addiction.
“People are increasingly dying of addictions,” says Ali Rezai, a neurosurgeon and principal investigator of the West Virginia trial. “Despite our best efforts with the evidence-based treatments that we have, there are a lot of patients who simply don’t respond, and they remain at a very high risk of ongoing health problems and death from overdose.”
Amid a deadly opioid epidemic, deaths related to alcohol use are also on the rise in the United States, according to the National Institutes of Health. That’s why some scientists think it’s time to try DBS for severe cases of addiction.
“The field is changing. We now understand that addiction is a brain disease,” says Lorenzo Leggio, a physician and scientist at the National Institute on Alcohol Abuse and Alcoholism and National Institute on Drug Abuse. “There’s no reason why a more inventive treatment like DBS shouldn’t be tried.”
Today, scientists recognize that addiction is a complex brain disorder driven by many factors, including brain circuits, genetics, the environment, and a person’s life experiences. And in recent years, they have gained a better understanding of the brain circuits — or populations of neurons — that are involved in addiction and other mood and anxiety disorders, giving DBS researchers something to target.
“We believe that with deep brain stimulation, we can access key parts of the circuits that are malfunctioning in those disorders to see if we can reset those circuits to influence behaviors,” says Nir Lipsman, the neurosurgeon at Sunnybrook Health Science Center in Toronto who operated on Plummer. “The idea with deep brain stimulation is that you are sort of overriding an abnormal circuit and trying to restore an equilibrium or balance to that circuit in the brain,” Lipsman says.
Similar to how a pacemaker controls abnormal heart rhythm by delivering electrical pulses to the heart, deep brain stimulation helps to control abnormal brain activity. DBS consists of three parts: the electrodes that go in the brain, a battery-powered pulse generator that’s implanted in the chest below the collarbone, and a thin wire that connects the two, delivering electric pulses from the generator to the brain electrodes.
To implant these components, neurosurgeons drill a nickel-sized hole in the skull, and using neuroimaging to guide them, thread a wire attached to an electrode to the location in the brain that they want to stimulate. For Plummer and the other North American addiction patients, the electrodes are placed in a part of the brain called the nucleus accumbens. There are two of these in the brain, one in each hemisphere. Patients are fully awake when the electrodes are placed into their brains so that surgeons can assess their brain function.
This content was originally published here.