UF: Deep-brain stimulation helping with OCD, Tourette's, along with Parkinson's
Published: Wednesday, October 17, 2012 at 5:40 p.m.
Last Modified: Wednesday, October 17, 2012 at 5:40 p.m.
A decade ago, deep-brain stimulation for Parkinson’s disease was considered a risky procedure. Today, it’s on the cutting edge of personalized medicine, and researchers at the University of Florida’s McKnight Brain Institute are at the forefront of its evolution.
“When we started in 2002, there were only a handful of places in the U.S. that did it. There was a lot of skepticism about the operation from internists and neurologists,” said Dr. Michael Okun, a neurologist at UF. “Now it has gone from crazy to cool to completely accepted.”
Okun published an article today in the New England Journal of Medicine that explains how the procedure is helping with Parkinson’s disease and other neurological conditions such as obsessive compulsive disorder, Tourette’s syndrome and depression.
Okun and Dr. Kelly Foote, a neurosurgeon at UF, have performed more than 800 procedures in the past decade, mostly in Parkinson’s patients whose medications have become less effective, leading to complications such as “on-off” fluctuations.
During the off periods, the medication stops working and patients’ symptoms — such as tremors or immobility — worsen. This happens in most patients after about five years, said Okun, and patients with off periods of more than three hours a day are good candidates for deep-brain stimulation.
During the procedure, doctors first identify the part of the brain to target. For most patients, that will be either the subthalamic nucleus or the globus pallidus, two tiny sites involved in controlling movement.
Doctors then drill a dime-sized hole in the skull so they can place a lead that delivers electric current to the troublesome spot responsible for the degeneration caused by the disease.
“You want to make sure that you take your time and get it right. Those leads have to be within a half-millimeter to work their magic,” Okun said.
Deciding where to place the lead also depends on the patient. “If you see a patient and tremors are important … maybe they are a dentist or a chef, they might choose one target in the brain. If it’s a singer or trial litigator, they may target another part of the brain.”
Patients are awake during the procedure — they receive local anesthesia at the top of the skull — and doctors monitor their symptoms while placing the lead so they can adjust it.
A month after the procedure, doctors place a pulse generator below the patient’s clavicle programmed to deliver the electric current to the brain through the lead.
That’s usually when patients begin to permanently experience fewer tremors and less stiffness. They also may reduce their medications, Okun explained. “It’s not a magic bullet, but it does improve symptoms.”
More than 100,000 deep-brain stimulation procedures have been performed worldwide, and Okun predicts that number could climb to 30 million over the next two decades, alongside the incidence of Parkinson’s.
Okun also is working on National Institutes of Health-sponsored trials using deep-brain stimulation for Alzheimer’s disease and Tourette’s syndrome. He and Foote also have used it for patients with obsessive compulsive disorder.
Foote described one OCD patient in his 30s who was obsessed with perfection. “Questions would paralyze him. His mother used to leave him, and he’d be in the same place six hours later,” Foote explained. “People thought he was psychotic or catatonic.”
After deep-brain stimulation, Foote continued, the patient smiled for the first time. “He was unfrozen. He was a prisoner in his own brain.”
Staff writer Kristine Crane can be reached at 338-3119 or Kristine.Crane@gvillesun.com.
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