HealthDay News — A history of concussion (HOC) has subacute and chronic effects on cingulate cerebral blood flow (CBF) and callosal microstructure, according to a study published online Aug. 25 in Neurology.
Nathan W. Churchill, Ph.D., from St. Michael’s Hospital in Toronto, and colleagues conducted a longitudinal magnetic resonance imaging study involving 61 athletes with uncomplicated concussion (36 with HOC) who were imaged at the acute phase of injury (one to seven days), the subacute phase (eight to 14 days), medical clearance to return to play (RTP), and one month and one year after RTP. One hundred sixty-seven controls (73 with HOC) were also imaged.
The researchers found that athletes with HOC had a greater decline in midcingulate cerebral blood flow subacutely, and at one year after RTP, they had greater declines in posterior cingulate CBF. HOC had no significant effect on fractional anisotropy; at RTP, athletes with HOC had higher mean diffusivity of the splenium. These effects were observed regardless of differences in sport concussion assessment tool domains or time to RTP.
“Our findings suggest that an athlete with a history of concussion should be watched closely, as these subtle brain changes may be worsened by repeated injury,” a coauthor said in a statement. “Additionally, our results should raise concern about the cumulative effects of repeated head injuries later in life.”