Friday, March 11, 2016
Concussion article in The Economist
FRED McNEILL, an American-football player, died in November at the age of 63. Between 1974 and 1985 he appeared for the Minnesota Vikings. After leaving them he became a lawyer but in later years suffered from dementia and was told that he had signs of chronic traumatic encephalopathy (CTE), a degenerative brain disease. His recent death has become a milestone in the understanding of brain disorders, for post-mortem examination has confirmed this diagnosis—retrospectively making him the first person to be so diagnosed while alive.
CTE is the physical manifestation in the brain of punch-drunk syndrome—or dementia pugilistica, to give its Latinised, medical name. As that name suggests, this form of dementia particularly affects boxers, who are hit on the head as a matter of course. But doctors now understand that it is also a problem in people like Mr McNeill, who get hit on the head accidentally in contact sports. Mr McNeill, along with several other retired players, volunteered to let researchers at the University of California, Los Angeles (UCLA) use a scanning technique called positron-emission tomography (PET) to look at their brains.
In his case, and in those of others who had suffered concussion (a form of brain injury that leads to headaches, dizziness and nausea, and causes blackouts in 10% of those who experience it), this revealed a pattern of abnormal protein deposits. Mr McNeill’s death enabled his scans to be compared with the results of an autopsy. That confirmed the PET-based diagnosis. Specifically, PET was recording deposits in his brain of a protein called tau, which is tied to CTE and other neurological disorders, including Alzheimer’s.
Suffer the little children
In the end, adult athletes can make up their own minds about what risks they wish to take. Children, though, cannot. It is therefore children who should attract the greatest attention. Not only are some children obliged to play contact sports at school, but they may also be participating in an environment that encourages a “stiff upper lip” when they are injured. Yet it has been clear since a study published in 2012 by Andrew Mayer at the University of New Mexico in Albuquerque that subtle brain changes in children who have sustained a concussion persist for months after the injury, even when there are no longer any obvious symptoms.
Work published last December by Charles Hillman of the University of Illinois found that children who had sustained a single sports-related concussion still had impaired brain function two years later.
Ten-year-olds with a history of concussion performed worse on tests of working memory, attention and impulse control than did uninjured confrères. Among the children with a history of concussion, those who were injured earlier in life had larger deficits. This study was small (it involved 15 injured participants) but if subsequent research confirms it, that will be great cause for concern.