Sunday, February 22, 2009

Curing OCD Through Electrode Implanted Neurostimulators

image by de_lima, sxc.hu


Attempting To Grasp That Which Is Not Graspable

People suffering from obsessive compulsive disorder (OCD) may not even realize it themselves; but those around them can see the suffering. A person who keeps going to the washbasin to clean their hands every fifteen minutes makes life difficult for family members who find it difficult to explain this behavior to strangers meeting them for the first time. Somebody who wants to take bath every half-an-hour during their waking hours is never ever able to leave the house. Somebody who returns back to the vehicle after locking the door the first time, to check, re-check and re-re-check whether it has been securely locked becomes an embarrassment for the people accompanying them. The disorder goes beyond one's control at some stage, and affects the quality of life of not only the person affected, but also the lives of those around.

image by marcos_bh, sxc.hu

This psychological condition is talked about in the same breath as are asthma and diabetes due to its prevalence. In the foreground of this fact is the buzz created by the press release issued by the FDA (available here) about the agency approving the use of an implantable device that delivers intermittent electrical therapy - called deep brain stimulation (DBS) -deep within the brain to suppress the symptoms associated with OCD. The approval comes under the category of "Humanitarian Device Exemption" (HDE), which means that, though the efficacy of treatment has yet not been established, the probable health benefits of the therapy have been found to outweigh the risks. So people suffering from OCD can get to avail themselves of this therapy right away before waiting for the efficacy to be fully established on humanitarian grounds. The therapy has been developed by Medtronic, Inc and is called "Reclaim DBS". It is expected to become available in the US by mid-2009, and will be administered at specific centers across the country. (There is a "Notify Me" online form on the company's webpage for those who wish to be notified by email when the treatment does become available.)

image by svilen001, sxc.hu

The therapy comes with a small battery-operated device that is implanted near the abdomen or the collar bone. This is in turn connected to four electrodes implanted in the brain at specific points with the help of insulated electric wires. The device generates pulses of the appropriate strength set by a clinician trained for this purpose.

image by agentoseis, sxc.hu

The OCD treatment targets the anterior limb of the internal capsule (AIC) in the brain, and within it the ventral capsule / ventral striatum (VC/VS). This is the point in the complex web of neural circuits where mood and anxiety get to be regulated.

image by sundesigns, sxc.hu

There are criteria for selecting candidates to undergo this therapy, such as they must have failed at least three selective serotonin reuptake inhibitors (SSRIs), they should not be scheduled to undergo electroconvulsive shock therapy or magnetic resonance imaging or deep tissue heat treatment (diathermy), females should not be pregnant, etc.

image by mmagallan, sxc.hu

The HDE tag implies that up to a max 4,000 such candidates can avail themselves of this therapy per year.

image by ilco, sxc.hu

How it works exactly, is not known. Of the subjects on whom clinical trials were carried out, 40% have been reported to have reduced their OCD symptoms. (The results of the trials have been published in the Feb 2009 issue of Biological Psychiatry, here: http://dx.doi.org/10.1016/j.biopsych.2008.08.029.)

image by eidesign, sxc.hu

The probes in the brain position themselves to the point where the thought-tokens that control mood and anxiety and apparently generate all the drives of obsession and compulsion. Thought-tokens that are beyond grasp. Can these physical, tangible pieces of fine wire grasp that which is not graspable? It is like a shot in the dark, relying on empirical observations. While wishing the new therapy all the best, here is another, non-invasive, technique that may alternatively be tried: Obsession Disorders - Cure Possible Through Meditation.

image by flaivoloka, sxc.hu

1 comment:

  1. Great posting. Very detailed. I can tell you are very passionate about the topics you write about. keep up the good work.

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