Fourteen months ago, Charlie Rashid's face was frozen in a blank expression, as if he were wearing a mask. Afflicted with Parkinson's disease, he had little muscle coordination and stumbled a lot. He couldn't run or hike, and his condition was getting progressively worse. He figured he had just a few years left until he ended up in a wheelchair.
But after undergoing deep brain stimulation -- a treatment that involves surgically implanting a small device that delivers mild electrical stimulation to selected areas of the brain -- his muscle control has improved dramatically.
Last October, Rashid did a 25-mile backpacking trip on North Manitou Island, Mich. Last December, he ran a half marathon. This summer, he went water skiing for the first time in six or seven years.
"I'm probably 50 percent to 75 percent better off than I was before," said Rashid, 51, a former stock broker from Franklin, Mich. "I probably put another 10 good years on my life."
That off-hand comment is supported by the results of a recent study.
Canadian researchers have found that the benefits of deep brain stimulation for patients with Parkinson's disease can last at least 10 years. The report was published in the Aug. 8 online edition of the Archives of Neurology.
In addition, deep brain stimulation has been used to treat conditions ranging from Tourette's syndrome to epilepsy.
Mayo Clinic doctors are researching the use of deep brain stimulation as a treatment for depression, obsessive-compulsive disorder and other conditions.
Dr. Jason Schwalb, the director of Movement Disorder and Behavioral Neurosurgery at Henry Ford Health System, performed the surgery on Rashid.
"What could be cooler?" Schwalb said. "You are making a huge difference in people's lives. And you get to learn about the brain, what it means to be human, how we work."
Schwalb said the next frontier of deep brain stimulation could be psychiatry. "Psychiatry is the big open field," he said. "If you understand the circuitry of a neurological disease or endocrinology disease that the brain plays a role in, like obesity, I can put an electrode there."
Most of the time, patients are awake during the procedure. A surgeon drills a small hole in the skull, exposing the brain. A thin electrode is inserted carefully into the brain, as a surgeon looks for the spot that is causing the problem.
A battery-operated device called a neurostimulator -- similar to a heart pacemaker -- delivers an electric current through the electrode.
When everything goes right, electricity passes through the electrodes, blocking the abnormal nerve signals that cause tremors.
Almost immediately, the symptoms disappear.
Schwalb said it is nearly impossible to know exactly how deep brain stimulation works because of the "complexity of the human brain."
And the theories of why it works have changed over time.
"You are doing a couple of things," Schwalb said. "You are probably turning off some neurological processes. You are also changing the tuning. It's like tuning the AM or FM knob, so you are amplifying the signals you want. You are getting 90.7 instead of 100.1 on your FM dial. You are sort of amplifying certain circuits in a way that important information gets through and nonsense information doesn't get through."
The procedure is used only for Parkinson's patients whose symptoms cannot be adequately controlled with medications. Schwalb said it "is not a therapy of last resort."
There are patients with Parkinson's who progress to a point that they are no longer candidates for deep brain stimulation.
And there are potential side effects.
"There are some downsides in using deep brain stimulation with patients who have Parkinson's disease," Schwalb said. "You can make patients better, in terms of their movement, but their thinking gets a little worse. Some of the Parkinson's patients have a tendency toward dementia. Sometimes we speed that up. We do a lot of screening to try to select patients that are not at high risk for those kinds of complications."
There are fewer risks in performing deep brain stimulation on patients with essential tremor, which is often confused with Parkinson's.
Essential tremor is a progressive neurological condition that causes a rhythmic trembling of the hands, head, voice, legs or trunk.
"With essential tremors, the downsides are exceedingly low," Schwalb said. "If you don't get the electrode where you want it, you can always go and move it. We have a pretty good understanding of the circuitry in the brain that is involved with tremor. We know where we can put electrodes to interrupt that circuitry."
Earlier this summer, Schwalb performed deep brain stimulation surgery on Patrick Terry, 63, who lives in Rose Township, Mich. Terry had essential tremor since he was in high school. His hand shook so badly that he couldn't write his name. He couldn't drink from a cup. And he was so embarrassed, he stopped going to family functions such as parties and weddings.
Schwalb drilled a hole in Terry's skull and inserted the electrode. When the electricit the right spot, Terry's hand stopped shaking.
"Cool," Terry said, breaking into a smile, while lying in the operating room at Henry Ford Hospital West Bloomfield.
The electrode was left in Terry's brain.
This month, the treatment will be fine-tuned and the quality of Terry's life should improve drastically.
"It is amazing," Terry said. "It's hard for me to explain."
Judy Terry, Patrick's wife, said she is amazed.
"It's a great breakthrough for people," Judy Terry said. "I work at a retail store and I see a lot of people come in, shaking, and I'm assuming they have tremors. It's a shame to see them struggle to get their wallet out, to get their money out. It's hard to watch them. You want to help them.
"I want to tell them, 'There is a procedure that can help you.'
"I just wish they knew about deep brain stimulation. It might be able to help."