A pacemaker-like brain implant has been cleared by the Food and Drug
Administration (FDA) for marketing as a treatment for severe and chronic
obsessive-compulsive disorder (OCD), the agency announced on February 19.
Surgically implanted deep brain stimulation (DBS) devices are already on
the market for treating tremor, dystonia, and movement disorder associated
with Parkinson's disease. In recent years scientists in Europe and North
America have been conducting clinical research on its effectiveness in the
treatment of OCD and depression by applying electrical pulses to different
brain circuits (Psychiatric News, December 19, 2008). Some of the
studies, although small, produced encouraging results for patients who are
severely disabled and have failed to respond to conventional treatments.
The device, manufactured by Medtronic Inc., is the first to be approved for
treating severe OCD. The FDA said that it granted the approval based on the
humanitarian device exemption regulation authorized by the federal Food, Drug,
and Cosmetic Act, which applies to devices "intended to treat or
diagnose a disease or condition affecting fewer than 4,000 people per year in
the United States."
The FDA reviewed clinical data from four centers at which 26 patients with
severe, treatment-resistant OCD received the implant and at least 12 months of
stimulation. The patients experienced on average a 40 percent reduction in
symptoms at the end of one year. Two-thirds of the patients had "marked
functional improvements" in psychological, social, and
occupational" areas, according to the company's announcement about the
study results. The pooled results of the multisite clinical trials were
published in Molecular Psychiatry online on May 20, 2008.
The device consists of a four-electrode stimulator to be implanted in the
brain, which is connected to a small battery that is surgically embedded under
the skin near the collar bone or the abdomen. The stimulator is implanted on
one side or both sides of the brain.
Adverse effects seen in the clinical trials were mostly related to the
brain surgery or resolved after postsurgery adjustments to the device setting,
such as altering the intensity and frequency of the electrical pulses. In the
clinical trials, all patients were required to have regular checkups after the
surgery, and some needed to have the device's battery replaced after a period
Medtronic said in the press release that it was going to conduct clinical
trials on DBS for treatment-resistant severe depression at five medical
centers in the United States. ▪