Emerging research indicates that deep brain stimulation (DBS) can improve motor symptoms and enhance quality of life in patients with advanced Parkinson’s disease.
The finding, reported in the online version of The Lancet Neurology journal is published by researchers at the University of Florida and 14 additional medical centers.
In the study, sponsored by a manufacturer of DBS devices, researchers found a constant current device helped to manage the symptoms of Parkinson’s.
Investigators say the device is designed to reduce tremors, improve the slowness of movement, decrease the motor disability of the disease and reduce involuntary movements that often are a side-effect of Parkinson medications.
After treatment, researchers analyzed 136 patient diaries and discovered longer periods of effective symptom control — known as “on time” — without involuntary movements.
“On time” for patients who received stimulation increased by an average of 4.27 hours compared with an increase of 1.77 hours in the group without stimulation.
Patients also noted overall improvements in the quality of their daily activities, mobility, emotional state, social support and physical comfort.
“I think it is safe to say since dopamine treatment emerged in the 1960s, DBS has been the single biggest symptomatic breakthrough for Parkinson patients who have experienced the fluctuations associated with levodopa therapy,” said Michael S. Okun, M.D., first author of the study, and the National Medical Director for the National Parkinson Foundation.
“This study validates the use of mild electrical currents delivered to specific brain structures in order to improve Parkinson’s disease in select patients with advanced symptoms, and additionally, it explored a new stimulation paradigm. Future improvements in devices and the delivery systems for DBS will hopefully provide exciting new opportunities for Parkinson’s sufferers.”
Researchers studied the effects of DBS on patients who have had Parkinson’s disease for five years or more. They were randomly assigned to a control group that delayed the onset of stimulation for three months, or a group whose stimulation began shortly after surgery.
All patients were followed for 12 months.
The deep brain stimulation procedure involves surgeons implanting small electrodes into an area of the patient’s brain that controls movement. The electrodes are connected to a device precisely programmed to use mild electrical current to modulate problematic brain signals that result in movement problems.
Technological advances over the past decade have greatly improved the ability to deliver and control DBS.
In the current study, voltage-controlled DBS devices delivered pulses of current that varied slightly with surrounding tissue changes.
Researchers believe the current system enables patients to have better motor control and an improvement in their quality of life when compared to the control group. The U.S. Food and Drug Administration approved the use of DBS for Parkinson’s disease in 2002.
At least 500,000 people in the United States suffer from Parkinson’s with about 50,000 new cases reported annually, according to the National Institute of Neurological Disorders and Stroke. These numbers are expected to increase as the average age of the population rises.
“The study answered some very important questions concerning cognition and mood with lead implantation (alone) versus implantation with stimulation. It also refutes the hypothesis that DBS increases depressive symptoms,” said Gordon H. Baltuch, M.D., Ph.D.
“The group’s results also showed a decrease in the infection rate to 4 percent from previously published 10 percent. It shows that American neurosurgeons and neurologists with their industry partners are improving the safety of this procedure and working in a collaborative fashion.”
Comparable with other large DBS studies, the most common serious adverse event revealed was infection, which occurred in five patients. Likewise, some participants also reported an increase in the occurrence of slurred speech, known as dysarthria.
“Technology is on the move, and we expect to see continued improvements to DBS approaches, equipment and materials,” said Okun. “DBS has set the bar high for the development of new therapies for advanced Parkinson’s disease patients.”
Source: University of Florida