Brains Are More Vulnerable To Chronic Impacts From Repeat Concussion Than First: Study 

WASHINGTON — Brains of athletes with a concussion history are more vulnerable to chronic changes and damage to the middle regions than people who have never suffered a concussion, as per the findings of a new study.

The research was recently published in the “Neurology” issue of the medical journal of the American Academy of Neurology.

The athletes participated in sports like football, volleyball, and soccer.

“We know concussions may have long-term effects on the brain that last beyond getting a doctor’s clearance to return to play,” said study author Tom A. Schweizer of St. Michael’s Hospital in Toronto, Canada.

“It is unclear, however, to what extent the effects of a repeated concussion can be detected among young, otherwise healthy adults. We found even though there was no difference in symptoms or the amount of recovery time, athletes with a history of concussion showed subtle and chronic changes in their brains.”

This study focused on changes within two areas in the middle of the brain that are especially vulnerable to concussion. Researchers focused on blood flow in the cingulate cortex and white matter microstructure in the corpus callosum.

Changes in blood flow and microstructure returned by brain scans can indicate underlying brain injury. The cingulate cortex is a layer of grey matter that coordinates sensory and motor skills. Below it is the corpus callosum, broadband of nerve fibers linking the two hemispheres of the brain.

The study looked at 228 athletes with an average age of 20. This included 61 with a recent concussion and 167 without. Within the first group, 36 had a history of concussions. Within the second group, 73 had a history of concussions.

Researchers took up to five brain scans of each recently concussed athlete, from time of injury to one year after returning to play.

Researchers found that one year after a recent concussion, athletes with a history of concussion had sharper declines in blood flow within one area of the cingulate compared to those without a history of concussions.

Those with a history of concussion had an average cerebral blood flow of 40 milliliters (mL) [1.35 fluid ounce] per minute, per 100 grams (g) [3.52 ounces] of brain tissue. Those without a concussion history had an average cerebral blood flow of 53 milliliters (1.79 fluid ounces) per minute per 100g of brain tissue.

In athletes with a history of concussion, in the weeks after a new concussion, researchers also found microstructural changes in a region of the brain called the splenium, which is part of the corpus callosum.

“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,” said Schweizer.

“Additionally, our results should raise a concern about the cumulative effects of repeated head injuries later in life.”

A limitation of the study is that athletes reported their own histories of concussions and could be inaccurate. Further research is needed that would follow athletes over time.

The study was supported by the Canadian Institutes of Health Research, the Canadian Institute for Military and Veterans Health Research, and Siemens Healthineers Canada.

(With inputs from ANI)

Edited by Saptak Datta and Krishna Kakani