Even Mild Concussions can Cause Lasting Effects on the Brain and Behavior

New research reveals that even a mild concussion from years ago can have lasting impacts on brain function and behavior in otherwise healthy individuals. This study enhances our understanding of traumatic brain injury and has implications for the evolving legal framework concerning sports-related brain injuries.

A concussion, a mild traumatic brain injury (TBI), results from events like falls, car accidents, contact sports, or assaults. Although often considered a temporary disruption to brain function, growing evidence indicates that TBI may increase the risk of dementia.

This has led researchers at the University of Cambridge in the UK to explore the long-term effects of even mild TBIs on brain health.

Prevent Dementia Study

As part of the Prevent Dementia study, researchers recruited 617 healthy middle-aged adults in the UK, aged 40 to 59. Participants underwent MRI scans and neuropsychological assessments to evaluate brain structure and function. Their history of traumatic brain injury (TBI) was assessed using the Brain Injury Screening Questionnaire (BISQ).

TBI was defined as having experienced at least one head impact that caused a loss of consciousness, with mild TBI being a loss of consciousness lasting less than 30 minutes. The study also evaluated participants’ risk of cardiovascular disease.

TBI History Among Participants

Among the 617 participants, 36.1% reported having experienced at least one TBI with a loss of consciousness. Of these, 56.1% had one TBI event, 27.4% had two, and 16.6% had more than two. For the 223 participants with a TBI history, injury severity was assessed for 76.2%: 94.1% reported mild TBIs, while 5.9% experienced moderate to severe TBIs with a loss of consciousness lasting 30 minutes or longer.

Cerebral microbleeds—small, chronic brain hemorrhages—were found in about 17.7% of participants. Those with a history of TBI, including mild TBI, had more microbleeds compared to those without a TBI.

Increased TBI events correlated with worse sleep, gait disturbances, more severe depression, and memory issues, though no attention deficits were noted. The mild TBI group experienced poorer sleep, more depression, and gait problems but did not show cognitive impairments.

Impact of TBI vs. Cardiovascular Risk Factors on Depression, Sleep, and Memory

The study evaluated the impact of TBI versus cardiovascular risk factors (like high blood pressure and diabetes) on these issues and found that TBI was a more significant factor in contributing to depression and sleep problems, overshadowing cardiovascular risk factors. For memory deficits, TBI’s influence was significant but was also affected by factors such as sex and age.

The researchers noted, “These findings show that, even in otherwise healthy middle-aged adults, a history of remote TBI is linked to observable changes in brain imaging and clinical features. This has important implications for future research and clinical practices, as well as for community policymaking.”

Researchers recommend TBI assessments for those with known brain injuries to identify high-risk individuals and enable earlier treatment, enhancing clinical practices.

Focus on TBI in sports has increased due to growing evidence of its long-term impacts. This is especially relevant in contact sports like boxing, soccer, and football, leading to shifts in the legal landscape.

Rising Sports-Related Brain Injury Lawsuits

Lawsuits for brain injuries in sports are rising. In 2015, the NFL settled a class action, agreeing to compensate former players with dementia or other concussion-related conditions. The NFL Concussion Settlement has paid nearly $1.2 billion to over 1,600 former players and their families. As of August 19th, 20,572 members are registered in the settlement class.

In the UK, a class action is underway against World Rugby, the Rugby Football Union, and the Welsh Rugby Union, with 295 former players alleging these bodies failed to protect player safety.

Head trauma is gaining attention in Australia. In April, 24-year-old AFL player Nathan Murphy retired after his tenth concussion, following medical advice. Justin Clarke, aged 22, also retired early in 2016 due to memory loss from a concussion. In 2023, two class action lawsuits were filed against the AFL for concussion-related injuries.

Chronic traumatic encephalopathy (CTE), a progressive brain disease linked to repeated head trauma, remains controversial. Studies suggest a strong association between CTE and contact sports, though a definitive causal link is not established. Research on former NFL players found 99% showed CTE signs, but diagnosis is only possible post-mortem.

These legal cases are driving increased safety measures in contact sports. The key issue is whether sporting organizations will update safety rules and concussion protocols. A cultural shift is necessary, as athletes frequently under-report concussions to avoid being sidelined or disappointing their team. This highlights the need to prioritize long-term health over immediate success.

Read the original article on: New Atlas

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