Current research is showing links between mild-to-moderate repetitive concussions (mTBI)—notably those suffered by young athletes—and the onset later in the life of cognition problems, psychiatric disorders including post-traumatic stress disorder (PTSD) and the neurodegener-active disease seen in many professional football players (CTE). Our current collaborative work shows that if additional head injuries occur during the “window of vulnerability” after an initial concussion, this can result in cumulative nerve cell damage and loss, and permanent disruption of normal brain function. This type of brain injury presents special challenges for diagnosis, evaluation of severity, and prognosis, especially in younger patients. Biomarkers are an objective means of managing return-to-play guidelines rather than relying solely on subjective symptom reporting, which can be unreliable.
Ongoing collaborative work by Iqbal Sayeed (BRL) and Dr. Erin Buckley in Pediatrics and Biomedical Engineering is showing that lower baseline cerebral blood flow (CBF) may correlate with increased cognitive deficits after repetitive concussions, and CBF measured early after a concussion might be a biomarker of the brain’s vulnerability to subsequent mTBI. This work has NIH (R-21) funding for additional studies, demonstrating that concussion disrupts not only CBF, but also many other factors, including oxygen metabolism, mitochondrial respiration, the strength of neural connections between brain regions, and cerebral autoregulation–the brain’s ability to maintain constant blood flow despite changes in blood pressure.
What is exciting about this new line of research is that promising biomarkers identified from our pre-clinical investigations can be translated to future human studies, and our measures can be quantified in humans in the emergency room or even in sideline sports settings.
Dr. Sayeed is now collaborating extensively with the pediatric brain trauma group at CHOA led by neurosurgeon Dr. Andrew Reisner. This work is identifying biomarkers that correlate with the extent of pediatric brain trauma caused by hypoxic ischemia and other forms of brain injury. This work is expected to continue through 2020.