Brain Implant May Ease Motion Disorder
Implant Stimulates Brain Area Affected by Rare Movement Condition Called Dystonia
Nov. 8, 2006 -- A brain implant device may ease a rare movement disorder
called dystonia by stimulating a certain brain area.
So say European doctors including Jens Volkmann, MD, of the neurology
department at Germany's Christian Albrechts University.
Dystonia includes "twisting, repetitive movements or abnormal postures
caused by involuntary muscle contractions," write the researchers.
They studied 40 people who had had severe dystonia for at least five
The patients were about 40 years old, on average, and lived in Germany,
Austria, or Norway. They had tried dystonia medications with "partial"
success, the researchers write.
First, the patients were videotaped while walking and tapping their fingers.
They also took psychological, quality of life, and mental skills tests.
Next, each patient got a deep brain stimulation device surgically implanted
in a part of their brain linked to dystonia.
A week later, the researchers programmed the devices in half of the patients
to start working. They set the other patients' devices to not deliver any brain
stimulation for three months.
The patients didn't know if their devices were programmed for brain
stimulation. Three months later, they were videotaped and tested again.
Patients were more likely to show movement improvements, less disability,
and better quality of life with the working implants.
Their movement scores (based on the videotapes) improved by 39%, their
disability dropped 38%, and their quality of life rose 30%, the study
In comparison, movement scores improved by 5%, disability scores by 8%, and
quality of life by 11% in the patients who didn't get brain stimulation.
The researchers extended the study for three more months. This time, they
set all the brain implant devices for deep brain stimulation.
The patients who continued deep brain stimulation for those three extra
months maintained their improvements.
Those who previously hadn't gotten deep brain stimulation caught up with the
other patients' gains.
The patients varied in their degree of improvement, and six didn't reach the
researchers' minimum goal of a 25% drop in dystonia symptoms.
During the study, 19 patients reported 22 side effects, including infection
after the implantation surgery and slurred but understandable speech.
The speech side effects were resolved or improved by adjusting the
stimulation, the researchers write.
The study was partly funded by Medtronic, which makes the deep brain
stimulation device. Medtronic is a WebMD sponsor.