MAYWOOD, Ill. – It's been widely reported that football and other contact sports increase the risk of a debilitating neurological condition called chronic traumatic encephalopathy (CTE).
But in the journal Neuropsychology Review, researchers are reporting only limited evidence showing a link between sports concussions and an increased risk of late-life cognitive and neuropsychiatric impairments.
Loyola University Medical Center clinical neuropsychologist Christopher Randolph, PhD, is a co-author of the paper. First author is Stella Karantzoulis, PhD, of New York University School of Medicine.
CTE is believed to be the cause of behavioral symptoms including irritability, anger, aggression, depression and suicidality; and cognitive symptoms including impaired learning, memory, language, information-processing speed and executive functioning. CTE is said to be linked to concussions and characterized by the build-up of abnormal substances in the brain called tau proteins.
But so far there is only limited evidence to support this CTE theory, Karantzoulis and Randolph write. These are among the limitations of the evidence:
The authors detail how CTE originally was identified in 1928 as "punch drunk" syndrome in boxers. There is a striking parallel between the controversy over CTE today and punch drunk syndrome decades ago. In 1965, for example, a skeptic argued that punch drunk syndrome symptoms seen in boxers could have been due to alcoholism and venereal diseases, which were common in boxers at the time.
"One cannot deny that boxing and other contact sports can potentially result in some type of injury to the brain," Karantzoulis and Randolph write. "There currently are no carefully controlled data, however, to indicate a definitive association between sport-related concussion and increased risk for late-life cognitive and neuropsychiatric impairment of any form."
The authors say more rigorous and definitive studies are needed than the case reports and samples of convenience that have been done to date.
The study is titled "Modern Chronic Traumatic Encephalopathy in Retired Athletes: What is the Evidence?"
Randolph is a professor in the Department of Neurology of Loyola University Chicago Stritch School of Medicine.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.