from the desk of associate editor Sandra Upson
The U.S. Food and Drug Administration recently approved two implantable devices that treat depression by transmitting electronic pulses to a nerve in the neck. Cyberonics Inc. says its two devices are 43 percent smaller than earlier model nerve stimulators and allow for easier monitoring by physicians.
As weâ''ve reported here and here, electronic methods of stimulating the brain to treat depression have historically faced bumpy approval processes. Cyberonics finally got the FDA nod to market its implant in the United States in 2005, four years after it gained conditional approval for depression therapy in the European Union and Canada. Vagus nerve stimulation therapyâ''and Cyberonicsâ''also received a devastating blow this year when Medicare decided not to cover it.
This controversial pacemaker for the brain works by having a surgeon insert an electrode into a patientâ''s neck and wrap it around a nerve. That electrode plugs into a pulse generator the size of a pocket-watch that the surgeon slides under the skin of the patientâ''s chest. Every few minutes, the pulse generatorâ''called a vagus nerve stimulatorâ''sends a buzz of current along the nerve and into the brain. Clinical trials have indicated that the treatment, which was originally used to tame epileptic seizures, is able to improve patientsâ'' moods in cases where more traditional psychiatric methods have failed. Vagus nerve stimulation therapy is not the only psychiatric treatment method vying for a slice of the antidepressant market, as Spectrum reported in March 2006.
According to Cyberonics, more than 45 000 patients have benefited from VNS therapy in the past ten years.