New CTE study provides uncertain link to football

A recent study published in the Journal of the American Medical Association-Neurology looks at the first large-scale study of the brains of deceased American football players. This study has attracted the attention of the media and comes at a time when parents must decide whether to permit their children to play football this season.

The study reports the results of neuropathological and clinical studies performed on 202 football players. The athletes studied played at multiple levels of competition: 14 high school, 53 college, 14 semiprofessional, eight Canadian Football League and 110 National Football League.

The principal neurological condition studied was Chronic Traumatic Encephalopathy (CTE). This entity has been studied in a variety of forms since Dr. Harrison Martland published his original studies in JAMA in 1928 titled “Punch Drunk.”

In 2009, Dr. Ann McKee and her colleagues at Boston University published a seminal paper in the Journal of Neuropathology describing CTE in three professional athletes. That same group published this most recent study. The pathology in CTE is based on brain atrophy and the deposition of tau protein. Tau protein is a normal constituent of the brain that is believed to leak after trauma.

Clinical findings in CTE are primarily changes in behavior, motor abnormalities and dementia. These features can be present in isolation or in total. Several of the athletes studied committed suicide.

The recent study reports an escalating frequency of CTE based on the level of football played. The percentage of players affected increased from 21 per cent of high school players to 99 per cent of NFL players.

Although this study demonstrates an association between CTE and football it does not prove that football is the cause of this condition. Among the faults in this study is “selection bias.” This refers to the fact that the only athletes who volunteered were those who had clinical symptoms. Healthy football players who went on to successful careers and stable family lives were not part of this study. 

Unfortunately, this study provides little direction for parents who are faced with a difficult decision. Several important factors to consider are whether a child has had previous concussions, if the child is of high school age and how important playing football is to the child’s overall well being.

Football is a great sport but parents must make responsible decisions regarding participation in any high-velocity collision sport.

Dr. Alessi is a neurologist in Norwich and serves as an on-air contributor for ESPN. He is director of UConn NeuroSport and can be reached at agalessi@uchc.edu