Wednesday, June 2, 2010

Loyola Study Finds "Brain Pacemaker" for Parkinson's Disease Equally Effective in Two Regions of Brain

"Great News for Patients"

MAYWOOD, Il. -- Studies have shown that a "brain pacemaker" called deep brain stimulation (DBS) is an effective treatment for Parkinson's disease.

But there's been debate over what region of the brain to stimulate -- the globus pallidus interna or the subthalamic nucleus. Now, a major study published in the June 3, 2010 New England Journal of Medicine is showing that stimulating either region resulted in similar improvements in motor function. There were small differences in non-motor effects such as mood and cognitive function.

"Both targets in the brain are viable for improving motor function. This is great news for patients," said Frances Weaver, PhD, of Edward Hines Jr. VA Hospital and Loyola University Health System. Weaver, one of the study's lead investigators, is a professor and director of the Program in Health Research at Loyola University Chicago Stritch School of Medicine and director of the Center for Management of Complex Chronic Care at Hines VA Hospital.

DBS is a treatment for Parkinson's patients who no longer benefit from drugs, or who experience unacceptable side effects. DBS is not a cure, and it does not stop the disease from progressing. But in the right patients, DBS can significantly improve symptoms, especially tremors. DBS also can relieve muscle rigidity that causes decreased range of motion.

"DBS increases the percentage of time that a patient is functional," said Loyola neurosurgeon Dr. Douglas Anderson, who has an active practice in DBS and movement disorders. "It also improves a patient's ability to move arms or legs in a more coordinated fashion. And there is a lessening of bradykinesia [slowness of motion]." Anderson is a professor in the Department of Neurological Surgery.

In the DBS procedure, a neurosurgeon drills a dime-size hole in the skull and inserts an electrode about 4 inches into the brain. A connecting wire from the electrode runs under the skin to a battery implanted near the collarbone. The electrode delivers mild electrical signals that effectively reorganize the brain's electrical impulses. The procedure can be done on one or both sides of the brain.

Weaver was first author of a pivotal 2009 study, published in the Journal of the American Medical Association, which found that DBS was more effective than medications in treating patients with advanced Parkinson's disease.

The new study included 299 Parkinson's disease patients at 7 VA and 6 university hospitals. Patients were randomly assigned to receive DBS in either the globus pallidus interna or subthalamic nucleus.

While there were no significant differences in motor function, researchers did find differences in other areas. Patients who received subthalamic stimulation required lower doses of L-dopa medications. But the subthalamic group also had slower visuomotor speed, which measures how quickly a patient thinks and acts on information. Also, depression got worse in the subthalamic group, but lessoned in the pallidal group.

"Based on the findings of this study, we expect that doctors will consider factors other than motor function when deciding what region of the brain to target," Weaver said.

In addition to Weaver, the study was led by first author Dr. Kenneth Follett of the University of Nebraska Medical Center and Dr. Matthew Stern of the University of Pennsylvania and Philadelphia VA Medical Center. It was funded by the Department of Veterans Affairs, the National Institute of Neurological Disorders and Stroke and Medtronic Neurological, which makes DBS systems.

About Loyola University Health System

Loyola University Health System (LUHS) is part of Trinity Health. Based in the western suburbs of Chicago, LUHS is a quaternary care system with a 61-acre main medical center campus, the 36-acre Gottlieb Memorial Hospital campus and more than 30 primary and specialty care facilities in Cook, Will and DuPage counties. Loyola University Medical Center’s campus is conveniently located in Maywood, 13 miles west of Chicago’s Loop and 8 miles east of Oak Brook, Ill. At the heart of the medical center campus is a 559-licensed-bed hospital that houses a Level 1 Trauma Center, a Burn Center and the Ronald McDonald® Children's Hospital of Loyola University Medical Center. Also on campus are the Cardinal Bernardin Cancer Center, Loyola Outpatient Center, Center for Heart & Vascular Medicine and Loyola Oral Health Center as well as Loyola University Chicago Stritch School of Medicine, Loyola University Chicago Marcella Niehoff School of Nursing and the Loyola Center for Fitness. Loyola's Gottlieb campus in Melrose Park includes the 255-licensed-bed community hospital, the Professional Office Building housing 150 private practice clinics, the Adult Day Care, the Gottlieb Center for Fitness, Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park.

Trinity Health is a national Catholic health system with an enduring legacy and a steadfast mission to be a transforming and healing presence within the communities we serve. Trinity is committed to being a people-centered health care system that enables better health, better care and lower costs. Trinity Health has 88 hospitals and hundreds of continuing care facilities, home care agencies and outpatient centers in 21 states and 119,000 employees.