Deep Brain Stimulation: Experts Warn About Aggressive Marketing

A paper published in the February issue of Health Affairs??– discussed at length in an article in the New York Times??– contains the sort of blunt, plain-spoken language you seldom read in academic journals. The authors, who include some of the most prominent neuroscientists and ethicists in the world, warn that manufacturers are misusing the FDAa??s humanitarian device exemption to promote deep brain stimulation as a a??treatmenta?? for obsessive compulsive disorder (OCD).

In fact, they make clear that deep brain stimulation is very much an experimental procedure. Research is still at an early stage, and the risks to patients are not well defined. When suffering is severe and no other treatment has provided relief, there is value in making available an intervention like deep brain stimulation. But misleading or biased information, no matter where it comes from, certainly undermines patientsa?? ability to calculate benefits and risks.

To enable deep brain stimulation, a surgeon must first implant electrodes in the brain and connect them to a pair of small electrical generators underneath the collarbone. Deep brain stimulation uses electricity to affect how brain signals are transmitted in particular areas of the brain. The image to the left, from the National Institute of Mental Health, shows how deep brain stimulation depends on the implantation of pulse generators below the collarbone and electrodes in the brain.

Specific??concerns are raised by the article in Health Affairs (and in our own article on this topic last year in the Harvard Mental Health Letter).

Among the concerns are:

• Inadequate research. Although deep brain stimulation is sometimes described as a a??pacemaker for the brain,a?? that is an oversimplification. Cardiac pacemakers monitor heart rhythm and trigger a heartbeat when necessary. While cardiac pacemakers have an established track record of success and clear guidelines for use, deep brain stimulation does not. (Among other things, when OCD symptoms do improve after deep brain stimulation, we still dona??t know exactly how or why the electrical stimulation helps.) Only about 100 people in the world have undergone deep brain stimulation for OCD — only some of the results have been published — altogether too small a number to standardize the procedure.

• Safety. Implantation of a deep brain stimulation device involves boring small holes into the skull (for the electrodes) and surgery on the chest (for the battery). Possible complications — as for any surgery — are infection and bleeding. The wires may break. And the devicea??s batteries can run out, sometimes without warning — causing rapid mood deterioration or behavior changes.

Furthermore, many alternatives exist. Deep brain stimulation is only appropriate for people who suffer severe and incapacitating symptoms and have exhausted every other treatment alternative. Fortunately, most people with OCD have other — and more proven — options. These include behavioral treatments, drug treatment, or some combination of the two. You can read more about treatment options in an article in the March 2009 Harvard Mental Health Letter.

- Ann MacDonald, Editor, Harvard Health Publications

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