Kimberly Spletter's knee would pop backward involuntarily, or her leg would shake uncontrollably. Sometimes she'd cross her legs tightly, trying to make it all stop — to no avail.
"I had to live with it," said the 50-year-old Frederick woman, who suffers from Parkinson's disease. "I tried to keep it to a dull roar, but that was the best that I could do."
That all changed in a matter of hours last week after Spletter underwent a groundbreaking procedure at the University of Maryland Medical Center that guided ultrasound waves through her skull to kill the brain cells interfering with her motor skills. She's participating in a clinical study looking at a cutting-edge way — known as focused ultrasound — to possibly treat certain Parkinson's symptoms noninvasively.
As many as 1 million people in the United States live with Parkinson's, a nervous system disorder that affects movement and becomes progressively worse over time. The disease most often afflicts older people, but about 4 percent of those suffering from it are under age 50. Symptoms include tremors, stiff limbs, trouble balancing and a general slowdown in movement. Medications can ease the symptoms but may trigger other side effects in patients.
Spletter was the first participant at the University of Maryland Medical Center to participate in the study, which also is being conducted in Korea, Canada and at the University of Virginia.
Spletter said many of her painful symptoms have subsided, and she is looking forward to evening walks in downtown Frederick as her condition continues to improve.
"I feel like a got a new lease on life," she said. "My quality of life has improved so much."
The question is for how long.
Scientists already know that targeting specific cells in the brain can minimize Parkinson's symptoms. But current treatments involve more aggressive tactics than the procedure doctors performed on Spletter.
The more common method is to cut a hole into a patient's head and put electrodes on a specific part of the brain. A stimulator implanted under the skin of a patient's collar bone transmits small electrical pulses to block symptoms.
Doctors also can use radiation to destroy cells or insert a needle through the head and use radio frequency waves to heat the cells to destroy them.
There were no cuts made to Spletter's skull as part of her procedure. The most she felt was intense pressure from a metal frame and helmet tightened around her head to prevent it from moving.
Ultrasonic waves were directed through Spletter's skull, much like a magnifying glass aims sunlight at a certain spot. The waves provide energy that is low enough that they don't damage the brain as they pass through, but, where they meet at single point, the energy adds up, creating enough heat to kill the cells.
The procedure was done as Spletter lay in a MRI machine so doctors could watch what was happening. They would stop from time to time to see if she was having vision problems or other side affects that might signal they weren't targeting the correct part of the brain.
Once they had a target, doctors asked Spletter to perform certain exercises, such as touching her thumb to her finger or pretending to press a gas pedal with her foot, to see if the surgery was working.
"The effects are immediate," said Dr. Paul Fishman, a professor of neurology at the University of Maryland School of Medicine, who has treated Spletter for several years and recommended she participate in the trial. "We saw improvement in her Parkinson's while doing her procedure."
Spletter could not believe what was happening.
"It was a miracle," she said.
The procedure performed on Spletter is one of many in the rapidly growing medical field of focused ultrasound. When the Focused Ultrasound Foundation was founded nine years ago, the therapy was being looked at to treat three conditions. Today, there are more than 58 ways the treatment is being used in various stages of research, development and commercialization.
It has been used to treat fibroid tumors, brain tumors and obsessive-compulsive disorder. There are plans for a clinical trial to see it could be used to treat Alzheimer's disease. The Parkinson's study builds off a previous pilot trial that looked at focused ultrasound to treat essential tremor, another progressive movement disorder.
"This is just one arrow in the quiver that neurosurgeons will have, if it works, to treat Parkinson's disease," said Dr. Neal F. Kassell, founder and chairman of the Focused Ultrasound Foundation, which is funding part of the study, and a professor of neurosurgery at the University of Virginia.
Kassell and the University of Maryland researchers caution that more research is needed to determine how effective the treatment is in treating Parkinson's. The study Spletter participated in will ultimately include 40 patients, who will be followed for a year.
"One of the things we don't know is whether this is durable," said Dr. Howard M. Eisenberg, principal investigator and the Raymond K. Thompson Chair of Neurosurgery at the University of Maryland School of Medicine. Spletter "was good today. She was seen a few days ago, and she was good. We don't know if she'll be good in six months."
A larger study will need to be done eventually.
"It is in its early stages," Kassell said. "It remains to be proven definitively in a rigorous scientific trial whether it provides true value in terms of improving outcomes and reducing costs."
The study also is limited in scope. For instance, researchers are looking only at subjects with symptoms on one side of their bodies. Parkinson's only affects the left side of Spletter's body. Participants also must have had a negative reaction to levodopa, a drug used to treat Parkinson's that sometimes leads to a poor quality of life.
Spletter was nervous about participating in the trial at first.
"There wasn't enough information out there about it," she said. "If I had been the 5,000th patient, I would be pretty calm about it. But fear of the unknown kept bothering me."
But Spletter's condition had become so bad that she was hoping for any relief. She couldn't walk anywhere and was almost always in pain. At restaurants, she sat on the inside of booths so people wouldn't stare at her trembling leg.
She knows there is a chance the effects of the procedure might not last long. For now, she is enjoying her new life — and looking forward to those downtown walks.
"It doesn't seem like a big deal," she said. "But when you can't do it, it is."