Pacemaker for the Brain Effectively Stops Tremors
Aug. 22, 2001 -- Each day, without thinking, most of us use our hands to perform thousands of simple tasks -- from brushing our teeth in the morning to turning off the lights at night. But for people with advanced cases of essential tremor -- a condition that causes uncontrollable shaking of the hands and other parts of the body -- these tasks can be difficult or impossible to perform.
Cresco, Iowa, farmer Jeff Ryan, 33, knows that better than anyone. Ryan was diagnosed with essential tremor when he was a teenager, but says he had his first shaking episodes before he was eight. Medications controlled them for a while, but none worked for very long.
Three years ago Ryan became one of the first people in the U.S. to have a device similar to a pacemaker implanted in his brain in an attempt to control the tremors. He says the brain surgery has completely changed his life.
"We got excellent results right there in the operating room," he tells WebMD. "I will never forget the look on my doctor's face when they turned the thing on and my hand was just as steady as a rock."
Ryan says the surgery has been great for him, and the brain stimulator manufactured by Medtronic Corp. of Minneapolis has been implanted in approximately 10,000 people worldwide since its introduction. But one of the first studies evaluating its long-term safety and usefulness gives the device a mixed report card.
Writing in the journal Movement Disorders, researcher William C. Koller, MD, and colleagues reported that deep brain stimulation of an area of the brain called the thalamus has provided excellent long-term clinical benefits for many essential tremor patients like Ryan. But they also note that the therapy has been compromised by a loss of effectiveness in many patients and complications related to the device in others.
Essential tremor, often confused with Parkinson's disease, can affect people of any age, but the vast majority of those with severe symptoms are elderly. Hand tremors ranging in severity from barely noticeable to violent and disabling are the most frequent symptom. Tremors tend to worsen with stress, and new research suggests the illness is largely inherited.
In this study, the researchers followed 49 patients who underwent surgery to have the deep brain stimulation "pacemaker" inserted and found that 16% had the stimulators removed due to loss of effectiveness during a 40-month follow-up period. In addition, there were several instances of device-related complications requiring a second brain surgery.
Neurologist James Tetrud, MD, of California's Parkinson's Institute, says many of his older patients who are candidates for the surgical implant choose not to have it because they fear the surgery more than the tremors.