Deep Brain Stimulation for “Freezing of Gait” in Parkinson’s Disease
University of Miami Miller School of Medicine researchers have developed a protocol to reach the gait-promoting center of the brain for patients with this type of walking difficulty.
Doris Gamelin was years into her Parkinson’s disease diagnosis when she began to experience a strange symptom.
“I’d be walking and everything would be OK. Then I’d come to a door frame or a change in flooring, like from a wooden to a tile floor, and I would freeze,” Gamelin said. “I couldn’t walk. And I’d fall. It happened quite frequently.
Gamelin broke her hip, arm and chipped a tooth because of those falls.
The 76-year-old said she was desperate for answers. She found them at the University of Miami Miller School of Medicine, where researchers are pioneering a new use of deep brain stimulation to relieve Parkinson’s patients of this debilitating symptom.
Freezing of Gait: A Unique Symptom of Parkinson’s Disease
Gamelin’s symptoms, called “freezing of gait,” occur in some with Parkinson’s, according to Corneliu Luca, M.D., Ph.D., associate professor of clinical neurology, co-director of the Movement Disorders Fellowship, and director of the Deep Brain Stimulation Program at the Miller School.
“It’s the inability to initiate walking. Your feet get stuck to the ground and when they try to make a step, they can’t,” Dr. Luca said. “This is very difficult to treat and many in neurology don’t know what to do about it.”
But laboratory research by Brian R. Noga, Ph.D., research professor at the Miller School’s Miami Project to Cure Paralysis, suggested deep brain stimulation had a place in treating patients like Gamelin. Dr. Noga and colleagues found that they could use deep brain stimulation to target the gait-promoting center in the mid-brain to improve their ability to walk.
Jonathan R. Jagid, M.D., professor of clinical neurological surgery, neurology, orthopedics and rehabilitation at the University of Miami Health System, The Miami Project and UM/Jackson Memorial Hospital, has since helped to develop an algorithm to reach that specific part of the brain in humans. He also has performed deep brain stimulation for freezing of gait in three people, including Gamelin.
Gamelin said the surgery, from which she went home the next day, gave her many months of walking free of the dangerous freezes. And she didn’t fall. Gamelin’s Parkinson’s has deteriorated in other ways in the last few months, but she said she doesn’t regret having the surgery.
“Before the surgery, they had me walk around a circle and it took me 22 steps. After surgery it took me five steps,” Gamelin said. “Done by experienced surgeons like those at the University of Miami, the surgery does what it’s supposed to do.”
Targeting the Brain Stem with Deep Brain Stimulation
Dr. Jagid said he believes the Miller School is one of the few facilities in the U.S. targeting this area of the brain stem with deep brain stimulation, using a “directional lead.”
“Other attempts have not used new technology,” Dr. Jagid said. “Directional leads steer currents, which gives an advantage when targeting this area of the brain stem.”
Results, according to Dr. Luca, have been spectacular.
“People who have an inability to walk, as soon as you turn on the electricity you are able to make steps, turn around, etc.,” Dr. Luca said.
Freezing of gait is a unique symptom complex of Parkinson’s. A subset of patients who have dopamine-resistant freezing of gait.
“That means that their Parkinson’s medication helps with a lot of the symptoms, but it does not help with their significant and profound freezing of gait,” Dr. Jagid said. “Before this, you really couldn’t do much for dopamine-resistant freezing of gait because the commonly used medication for Parkinson’s was not working for that particular symptom in that particular subset of patients.”
Deep brain stimulation has long been used to address other types of debilitating neurological symptoms, from tremors to slow movement and stiffness.
The standard approach to deep brain stimulation, however, will not help freezing of gait.
“The difficulty with this particular area of the brain stem is that the target that we’re trying to put this electrode into is not visible on imaging. We at the university have developed a protocol that allows us to try and hone in on where this small nucleus is in the brain stem,” Dr. Jagid said. “The way we do it is by using fiber tracking to get a particular type of image that allows us to see and target some of the deep circuitry of the brain.”
Dr. Jagid said he and Dr. Luca continue to accrue patients who are candidates for the surgery to better determine consistency of results and the procedure’s safety.
“If the safety record is proven and we see a few more patients with the same kind of results, the next step would be to submit grants for funding and then potentially carry this onto a larger study,” Dr. Jagid said.
While standard deep brain stimulation has about 25 years of safety and effectiveness data and is FDA-approved, there is still much to learn about this specific approach and indication.
“We are following these patients over time. We don’t have long-term data but, so far, the results are lasting. That is the hope that it’s more than a temporary solution,” Dr. Luca said.