Deep Brain Stimulation Shows Promise for Obsessive-Compulsive Disorder
Posted Oct 04 2010 12:17pm
Monday, October 4, 2010
By Kate Kelland
LONDON (Reuters) - Using electrodes to stimulate areas deep within the brain may be able to help patients with severe obsessive compulsive disorder OCD who do not respond to any other kinds of treatment, Dutch scientists said on Monday.
In a study of 16 patients with extreme forms of OCD, researchers from Amsterdam University's Academic Medical Center found after using a deep brain stimulation (DBS) system of electrodes patients saw a dramatic reduction in symptoms.
With DBS therapy, a surgeon implants a generator or battery into the wall of the chest to send electrical pulses to electrodes that target specific areas deep inside the brain.
"It's a bit like a pacemaker for the brain," said Damiaan Denys of Amsterdam University, who led the study and published its results in the Archives of General Psychiatry journal.
"In our study it looked very promising. We saw symptom decreases of around 50 percent on average, and sometimes up to 80 or 90 percent -- which is extraordinary in these patients."
Obsessive compulsive disorder is a psychiatric disorder characterized by persistent thoughts, or obsessions, and repetitive ritualistic behaviors, or compulsions.
It affects men and women equally and is estimated to affect around two percent of people worldwide at some time in their lives. If untreated, OCD can destroy a person's capacity to function at work, in social situations and at home.
Current treatments for OCD include cognitive behavioral therapy and medicines, but these options do not work for all patients. According to Denys, around 10 to 15 percent of OCD patients do not respond to the best available treatments and remain severely affected by the condition.
Denys' team tested DBS therapy, using a system of electrodes made by medical device firm Medtronic, on 16 such patients who had exhausted all other treatment options.
"These patients have obsessive and compulsive symptoms for between 10 and 16 hours a day, so they are completely incapacitated, unable to work, and really extremely ill. A lot of them just want to die," he said in a telephone interview.
"On average they had been suffering for 16 or 17 years and had tried at least eight or nine different treatments."
The study had three phases. After having electrodes implanted in the nucleus accumbens -- a brain area critical to the motivation and reward system -- the patients had a first phase of eight months during which the device stimulated their brains and they were assessed for OCD symptoms every two weeks.
Patients then went through a one-month phase in which they were randomly assigned to have the electrodes turned on or off in two-week blocks, and finally there was a 12-month maintenance phase in which the DBS systems were all turned on again and the patients were monitored every three months.
The researchers ranked obsessive-compulsive symptoms on a scale of zero to 40 and patients were classified as responding to treatment if their score fell by at least 35 percent.
The results showed that in the first phase, the average score decreased by 46 percent from 33.7 to 18.0. Among the nine patients classified as responders, scores decreased by an average of 23.7, or 72 percent.
Denys said the findings suggested the need for larger studies on more patients with severe OCD and said his team was now working on such trials.