

One day, after years of agony, an Australian man took a large quantity of dry ice and intentionally damaged his left leg, so that a surgeon would have to amputate it.

The action was intentional and the man, Robert Vickers, described the feeling of waking up in the hospital without his leg as "absolute ecstasy." He's one of a small number of people who have what psychiatrists have come to call body integrity identity disorder in which patients report the desire to have one or more of their limbs amputated because the extremities don't feel like they "belong" to their bodies.

The disorder is the subject of a debate between psychiatrists and neuroscientists about whether the brain physiology causes the psychiatric condition or whether the causality runs in the other direction. New research by both sides has yielded fresh ammunition for both interpretations, highlighting how difficult it is to separate biological from psychological phenomena.

Columbia University psychiatrist Michael First helped pioneer the identification of the disorder and his latest research suggests it's just a subset of a larger psychiatric condition in which people become fixated on being disabled.

On the other hand, Paul McGeoch's recent work at the University of California, San Diego seems to explain the disorder as a purely neurological disease resulting from a malfunctioning right parietal lobule, which appears to maintain the mind's body map. His lab used fMRI to determine that four self-reported BIID patients' right parietal lobules didn't light up when their unwanted limbs were touched. Normal people's did.

"Oh, this is certainly a breakthrough. We were stunned by the results," David Brang, a graduate student who co-authored a paper on the study with McGeoch, said recently on the Australian television show on which Vickers told his amazing story. "It’s very clear that this is a neurological phenomenon when it always been thought of as a psychological issue."

First, though, disagrees. He's in the midst of a new study about a small group of people who don't want their limbs amputated, but do want to be disabled in some other way. Some of the 47 people First has interviewed want to be paraplegic, for example, and feel that their healthy bodies are mismatched with their internal representations of themselves.

The study is a follow-up to an similar set of psychiatric evaluations First did on people who wanted their limbs amputated. The new group turns out to have a lot of the same feelings and desires as people with BIID.

"The vast majority of people that I interviewed are very similar to the BIID group," First said.

Both groups express a lifelong desire to be disabled. They pretend to be disabled. They occasionally injure themselves in an attempt to reach that state, although First said only one person reported an attempt to induce paraplegia by injecting alcohol into the spine.

His findings could indicate there is a deeper psychiatric disorder underlying the neurophysiological observations from UCSD.

"It suggests that the common factor has to do with the desire to be disabled," First said. "As children, we see disabled people all the time and for whatever reason. For certain children, they see people who are disabled and decide they want to be that way. The nature of the disability is variable, but the desire is common."

First doesn't rule out the importance of the fMRI study, but he disputes that the results show the cause of the illness.

"You are seeing a brain manifestation of a psychiatric illness," he said. "I find their work exciting, but I'm dismayed at how they came to their conclusion."

One area where the neurological results could be helpful is to change the treatment regimen for BIID patients who want amputations to include remediation exercises to retrain the brain into readopting a limb as its own. How such a treatment could be accomplished for people who want to be paraplegic is unclear.

Via Mind Hacks.

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Image: flickr/wackelijimrooster

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