Thursday, September 6, 2007

It's wrestling's fault...until it's a wrestler!

Article: Benoit's Brain Showed Severe Damage From Multiple Concussions, Doctor and Dad Say
An article discussing brain damage said to occur to the wrestler who killed his wife and kid this summer. I have great respect for neuroscience, and the things neuroscientists have found about the brain over the past few decades is truly amazing. That said, it's important to be critically skeptical of "brain imaging" comparisons. The article includes a picture comparing images of Benoit's brain to that of a "healthy" brain, and reads:

The tests...show that Benoit's brain was so severely damaged it resembled the brain of an 85-year-old Alzheimer's patient.

Certainly, there's debate about what can be determined by brain scans. This article, though, paints an interesting picture.

After almost 30 years, researchers have not developed any standardized tool for diagnosing or treating psychiatric disorders based on imaging studies.

Why the difficulty in using brain image comparisons?

(B)rains are as variable as personalities. (For example) ... researchers have found that people with schizophrenia suffer a progressive loss of their brain cells: a 20-year-old who develops the disorder, for example, might lose 5 percent to 10 percent of overall brain volume over the next decade, studies suggest. Ten percent is a lot, and losses of volume in the frontal lobes are associated with measurable impairment in schizophrenia, psychiatrists have found. But brain volume varies by at least 10 percent from person to person, so volume scans of patients by themselves cannot tell who is sick, the experts say. (emphasis mine)

The same reasoning based on brain variability applies to brain activity images, too. I know nothing of Benoit's brain, and when the doctor claims, "This is something you should never see in a 40-year-old" - referring to his brain characteristics, I have not reason to doubt his claim. Also, the doctors have an interesting theory, based on studying the brains of others who've suffered concussions and later killed themselves:

(They) theorize that repeated concussions can lead to dementia, which can contribute to severe behavioral problems.

So, I don't mean to be critical of the doctors. But most people will look at the brain images and feels there's a huge difference, when, in reality, unless one is well-trained in reading such images, and one has huge amounts of comparison data, the images shown in the news story mean nothing.

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