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| |  ICPDMD: Brain Surgery May Help Patients With Severe Parkinson's Disease NEW YORK, NY -- Oct. 14, 1998 -- As many as one in five patients suffering from Parkinson's disease may be helped by a new surgical procedure that is showing promise in controlling a broad range of the most debilitating symptoms. These findings are the result of research presented here today at the fifth International Congress of Parkinson's Disease and Movement Disorders. The research, which also is being published today in the New England Journal of Medicine, goes beyond previously reported surgical interventions. Subthalamic nucleus stimulation (STN) involves implanting electrodes in the STN, an area of the brain that controls movement, to suppress abnormal neuronal overactivity in this structure. The experimental procedure was pioneered by doctors at the University of Grenoble, France, who have treated patients with advanced Parkinson's disease for whom drug therapy has failed. Levodopa, the standard drug therapy, is the most effective treatment for Parkinson's disease, but after five to 10 years of treatment, the majority of patients experience disability that is not controlled by the drug. High-frequency stimulation of the STN offers a new treatment approach for these patients. Parkinson's disease affects approximately one million people in the United States and more than seven million world-wide. Before surgery, many patients taking levodopa are symptom-free only a few hours of the day. After high-frequency stimulation of the STN, patients enjoy a majority of the day free of the motor symptoms of the disease, including tremor, rigidity, gait disturbance and falling. In one of several University of Grenoble studies on the topic being presented at the meeting, 10 patients who received STN stimulation bilaterally (on both sides of the brain) were followed for 12 months, another five for 24 months and another five for 36 months. All were able to begin living independently and all experienced significant reduction of Parkinson's symptoms. The improvement was stable over time in the group followed for 24 and 36 months. One patient developed a supraventricular hematoma, one developed an infection which required temporary removal of the electrodes, and one died of unrelated causes. "Because this involves neurosurgery and a two percent to five percent risk of bleeding or other complications, only severely disabled patients are eligible," said Pierre Pollak, M.D., who pioneered the treatment. He is professor of neurology and chairman of the neurology department at Joseph Fourier University of Grenoble, University Hospital of Grenoble. "The best candidates for STN are those with advanced Parkinson's disease complicated by motor fluctuations and dyskinesias -- sudden abnormal involuntary movements -- induced by chronic levodopatherapy which is 10 percent to 20 percent of all patients with the disease. Their symptoms include severe akinesia, or inability to move, rigidity and tremor and they are drug resistant." At the University of Grenoble, 78 patients have been treated since 1993. The average treatment age is 55. Another benefit of this surgery is that patients are often able to eliminate or decrease the amount of levodopa they take, Dr. Pollak said. At the University of Grenoble, 20 percent of patients treated no longer take levodopa and, on the whole, the amount they take has been decreased by an average of 70 percent, Dr. Pollak explained. STN involves accessing the brain through a small hole in the skull. A magnetic resonance (MR) image is obtained prior to surgery to specifically locate the target area on the subthalamus. Two quadripolar electrodes are placed, one on the right and the other on the left of the subthalamus nucleus and a wire connecting the electrodes is implanted under the skin and linked to a pacemaker device, which is worn on the chest. The pacemaker is programmed to control the amount of electrical stimulation sent to the subthalamus and is periodically checked and adjusted by a physician. The patient can turn off the device. STN is the newest form of Deep Brain Stimulation, which was developed at the University of Grenoble for the treatment of movement disorders. Two other types of Deep Brain Stimulation are similar to STN, but involve stimulating different parts of the brain. Thalamic stimulation was cleared by the U.S. Food and Drug Administration for use in controlling tremor in September, 1997, but is not helpful for Parkinson's other motor symptoms. The second technique, pallidal stimulation, has helped some Parkinson's patients, but appears to be less promising than STN. Thalamic stimulation and pallidal stimulation are beneficial for other movement disorders. All three areas of the brain (thalamus, pallidum and subthalamus) play a role in controlling the body's movement. Deep Brain Stimulation may replace the surgical procedure known as lesioning, or burning a tiny area of the brain, in those areas. Lesioning has been used for a number of years to control symptoms of movement disorders, including Parkinson's disease. Deep Brain Stimulation is less risky and apparently, more effective, than lesioning because it maximises benefits and minimises adverse affects, Dr. Pollak added. Related Links: New England Journal of Medicine
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