Study Probes Deep Brain Stimulation Failures
Study Shows Procedure Offers Benefits, but Some Complications Preventable
June 13, 2005 - A new report about
failures shows complications from the
procedure may be avoidable.
The report in the Archives of Neurology does not dismiss deep brain
stimulation, an FDA-approved treatment for essential tremor, and uncontrolled muscle
movement (dystonia). In fact, the doctors who wrote the report say "deep
brain stimulation offers dramatic benefits for appropriate candidates."
They also caution that the 41 cases they describe don't represent everyone
who gets deep brain stimulation. However, the complications experienced by
those patients were "potentially preventable," write the University of
Florida's Michael Okun, MD, and colleagues.
In deep brain stimulation, electrical pulses are delivered by electrodes
that are placed inside the brain. The electrodes are connected by wires to a
type of pacemaker that is implanted under the skin of the chest.
The 41 patients described in the report came to the University of Florida
Movement Disorders Center or Beth Israel Movement Disorders Center citing
disappointment with deep brain stimulation. The decision to use deep brain
stimulation and the devices' implantation happened elsewhere.
Issues included electrodes that weren't placed in the best spot, dead
batteries, and improperly programmed devices.
What's more, five patients didn't have one of the three conditions approved
for deep brain stimulation treatment, even though nearly three out of four had
been evaluated by a movement-disorders neurologist before the procedure.
More Than Half Improved
Ultimately, about half (51%) of the patients had "good" outcomes,
after appropriate interventions. Another 15% improved modestly, while 34% had
"persistently poor outcomes despite maximal intervention," says the
Some cases involved tweaking the medications that the patients were taking.
"Patients with movement disorders, with and without deep brain stimulation,
require frequent medical adjustments," say Okun and colleagues.
There has been a surge in the number of centers offering deep brain
stimulation since the FDA approved the procedure, according to the report.
However, there currently is no standard screening for deep brain stimulation
surgery, and even the best screening isn't perfect, says the report.
Ideally, a multispecialty team would coordinate treatment -- monitoring
medications and following up with the surgeon, say Okun and colleagues. They
note that implanting centers are becoming more experienced.
"We are hopeful that this experience, along with ongoing efforts to
educate deep brain stimulation practitioners regarding effective practices,
will result in global improvement in the outcomes of deep brain stimulation
surgery," they write.