CTE and its Immersion in the World of Neuroscience

Concussion – a 2015 movie starring Will Smith – documents the neurological discoveries of Dr. Bennet Omalu. Dr. Omalu is a forensic neuropathologist who brought chronic traumatic

encephalopathy (CTE) to light in 2002 through the postmortem treatment of National Football League Hall-of-Famer Mike Webster. The movie expresses Dr. Omalu’s pursuit of recognition

and his battle against the heavy grain of the NFL to validate the significance of CTE in modern-day football. Dr. Robert Stern of Boston University’s Center for the Study of Traumatic

Encephalopathy conducted a study of CTE and its neurological effects in 2013. His work implies that the disease is more significant than its portrayal in a blockbuster film and goes far beyond concussions.

CTE is a neurodegenerative disease that is characterized by an extensive spread and buildup of hyper-phosphorylated tau (p-tau), an observable protein that appears dark brown under a

microscopic cross-section, in the cerebral cortex of the brain, contrasting the normal light-tan color of brain tissue. CTE has been recorded and documented in a variety of athletes, both on the

amateur and professional levels, that have participated in contact sports. The disease has also been found in military personnel that were subject to explosive blasts, and others who were

exposed to repetitive brain trauma (RBT). RBT includes both concussive and subconcussive head trauma, which are impacts to the brain that can be medically diagnosed as a concussion and

also impacts that aren’t medically diagnosed, but still play a role in the long term effects of the brain. All of the recorded and confirmed cases of CTE were incited by exposure to RBT, but not

all those exposed to RBT end up developing CTE. This implies that there are other risk factors, including genetic make-up and specific alleles, that may play a significant role in the

development of this complex disease. In order to discover more about the long and short term effects, and possible diagnostic determinants of CTE, Dr. Stern and his research team coordinated a study to answer these unresolved questions.

Dr. Stern’s 2013 study focuses on the signs and symptoms associated with priorly tested and neuropathologically confirmed cases of CTE. The goal of his research was to examine, postmortem, the clinical presentations demonstrated by 36 former athletes with confirmed CTE, and determine if there is a correlation between their cognitive functions, behavior/mood, and the disease.

The methodology involved in this research study included CTE neuropathologic staging, which categorized each of the cases into one of the four categorical stages of CTE. I is the least severe

stage, and IV is the most severe. Staging is based on the intensity and significance of the patient’s p-tau pathology, the visual determinant of the disease, located on the outer lining of a

cerebral cortex cross-section. Interviews and medical histories were also conducted and recorded respectively, and APOE genotyping was done to account for the genetic factors of CTE. APOE genotyping is the process of extracting DNA from the brain tissue in order to check for certain genes that have been recorded in previous cases of CTE, of which may correlate to the growth of

the disease. From these procedures, Dr. Stern and his research team were able to conclude that there may indeed be two different categories of clinical representations for CTE. The first is the

patient’s initial expression of behavioral and/or mood changes, and the second the patient’s initial expression of cognitive dysfunction.

Those in the behavior/mood group typically demonstrated symptoms of CTE at a much younger age than the cognitive group. Additionally, members of the behavioral/mood group eventually

developed cognitive impairments, while a significantly lower number of members in the cognition group demonstrated any sort of behavioral change throughout their illness. There were multiple clear differences between characteristics of the two groups of CTE patients. The behavior/mood group was typically much more "explosive, out of control, physically and verbally violent, and depressed.” In comparison, a part of the cognition group reported having “impaired episodic memory” and the cognition group was significantly more susceptible to dementia than those in the behavioral/mood group. This finding may have been confounded by the additional factor that the members of this group were also typically older at the time of their death.

Due to the small sample size of this study, Dr. Stern and his research team could not be completely certain whether or not these two symptom subtypes are representative of all

individuals that develop CTE. This study may bring neuroscience a step closer to resolving the destructive issue of this disease. Further investigation and research is necessary to confirm Dr.

Stern’s findings. Doctors, researchers, and corporations across the country will continue to work together and join forces to find a method to diagnose CTE while the patient is still living. CTE is

a new and significant topic of study in the world of neuroscience today, and the efforts being made by Dr. Stern and his colleagues in the field will one day save and better the lives of many.

References:

"About CTE | Bennet Omalu Foundation." Bennet Omalu Foundation. Web. 12 Oct. 2016. Stern, R.A., et al. "Clinical Presentation Of Chronic Traumatic Encephalopathy." Neurology 81.13 (2013): 1122-1129.Scopus®. Web. 12 Oct.