The Study
The purpose of this study is to examine how and why constant hits to the head or concussions cause chronic traumatic encephalopathy in retired NFL players. It is assumed that repetitive brain impacts in the NFL sport are the sign of the clinical symptoms observed in CTE (Gavett, Stern, & McKee, 2011).
Research Method
The study design was a cross-sectional, control case study. A cross-sectional study would examine the relationship between concussions and CTE in retired NFL players. The data collected about concussion will be used to determine what happens to players only after retirement.
Sampling
In this cross-sectional study, a sample of participants will be randomly obtained among the retired NFL players. The retired NFL athletes shall be recruited from local centers. The NFL association local chapter would be requested to inform retired NFL players about the study. To get a reasonable number of retired NFL players for the study, recently 50 retired players aged between 41 to 65 years would be recruited.
The institutional review board will have to approve the study to ensure that it adheres to the required ethical standards on human participation. All respondents will have to provide written informed consent to take part in the study.
All players will undergo a standardized assessment by a certified psychiatrist. The assessment will focus on current activities (life after retirement), medical condition, and psychiatric history, as well as any family history involving neuropsychiatric conditions, including Alzheimer’s disease and dementia. All information about retired NFL players’ history of concussion would be collected from any official register of the NFL Injury Surveillance System (if available) and self-report. They will also complete the 17-item Hamilton Depression Scale (HAM-D). Participants would undergo laboratory screening assessments and structural imaging scans, either MRI or CT (magnetic resonance imaging or computed tomography) to identify other possible causes of mental conditions, such as tumors and stroke.
Control participants would also be recruited using advertisements targeted at the locals. The screening will be conducted to ensure a stable health condition. Any control participants with cases of concussions would not be included in the study, as well as any other control participants who have a history of engaging in contact sports with hard blows, such as wrestling, boxing, college football, reported neurologic or psychiatric conditions and cognitive challenges. Once healthy control participants have been identified, they would be matched on various parameters, including age, educational achievements, and IQ to the sampled retired NFL players who have taken neuroimaging assessments and included in the final sample for the study. Further, control participants would be excluded based on substance use, traumatic brain injury, and the use of anti-inflammatory drugs.
Instrumentation
The main goal of the survey questionnaire would be to collect data to answer the research question. Also, the data would demonstrate how the retired NFL players’ cases of concussion and ECT differ from the control participants. There are general symptoms, such as back pain, headache, seizures, nausea, and syncope. Thus, the questionnaire would be designed to assess specific signs related to mild traumatic brain injury (MTBI) or concussion to demonstrate how they differ from the rest of the population of similar ages.
Neurocognitive tests will assess general intelligence; attention and cognitive flexibility; language; visuospatial skills; memory; and mood.
A professional neuropsychological technician or neuropsychologist would conduct all these tests. Further, a cognitive neurologist will perform clinical assessment after assessment of participants’ medical history, neurologic assessment, and behavior review.
The data collection instrument will also be used to collect data for FDDNP- positron emission tomography (PET) to assess tau tangle and amyloid plague mass in participants’ brains. The FDDNP signals are used to identify Alzheimer’s disease from MCI and general aging and forecast potential cognitive degeneration in people without demented cases. Some past studies have tested different tau tracers in human brain tissue sections and determined that FDDNP is the only suitable PET assessment of tau. All PET scans would be conducted for the region of interest (ROI) for further analyses using a suitable clinical instrument.
Overall, the instrument will assess concussion history, neurocognitive health, and physical health, as well as sociodemographic characteristics of participants of the retired NFL players who would qualify for the study. The study instrument will be pilot-tested on a given number of samples to ensure that it meets reliability and validity requirements. This process will require assessments of other attributes to ensure instrument precision and accuracy, and critical attributes will be determined if they offer a good measurement of the study interest. Any changes in the wording of the instrument will be conducted based on the outcome of the pilot test to ensure that it is understandable and acceptable to participants.
Data Collection
After incorporating findings from the pilot study, data will be collected using a survey questionnaire. The research will administer the questionnaire to a sample of the targeted retired NFL players. Any interviewers who may be involved in data collection will have the necessary skills to collect technical data. Interviewers will review all research questions and understand the study to ensure that they comprehend its contents and objective to enhance the collection of accurate, reliable data. Interviewers will ask consistent questions and offer any assistance about interpretation. All processes of the interview will be consistent from one respondent to another.
Data Analysis
It is anticipated that a small number of respondents may be found to participate in this study. Hence, non-parametric tests, such as the Mann-Whitney test, Spearman correlation, and Kruskal-Wallis test would be considered for data analysis. Further, the two-sample Wilcoxon test will be used for depression measure, cognitive scores, and FDDNP binding levels. The FDDNP binding levels will also be used to explore potential concussions in retired NFL players when compared with the control subjects (Small et al., 2013). Further analysis will involve a t-test to determine to mean score differences in cognitive variations between the participants and the control group. The control subjects would be identified and matched to minimize potential bias and strive for similarity with the retired NFL players. Participants and control subjects will be matched based on age, body mass index (BMI), education, and any existing mental conditions. Descriptive statistics will be computed for the retired NFL players and control subjects (Casson, Viano, Haacke, Kou, & Kou, 2014). To ensure that concussions are effectively understood, every case will be analyzed independently, and summary measures presented with 95% confidence intervals. Data analysis will be performed using SPSS.
Limitations
Some studies have demonstrated that responses among retired NFL players tend to be low (Kerr et al., 2014; Coughlin et al., 2017). Hence, the findings of this study may not be generalized to include other retired NFL players who will not take part in the study. Besides, the sample may represent a small percentage of all retired NFL players in the US. This study also recognizes the possibility of selection bias, which can be demonstrated when reliable clinical correlation with pathological results would not be attained (Ban, Madden, Bailes, Batjer, & Lonser, 2016). Nonetheless, the findings will demonstrate the outcomes of data obtained from diverse participants. This study will be cross-sectional. However, retired athletes should be observed for longer periods to determine changes in their conditions.
A longitudinal study should follow this study to provide conclusive results, especially where retired athletes use medications. This study may also possibly face information bias limitations. Athletes may experience biased effect estimates of the present conditions in self-reporting. Finally, retired NFL players may also experience normal cognitive degeneration because of aging, leading to differential recall bias. Consequently, some respondents may focus on their health and wrongly attribute such cognitive developments to concussions. Additionally, it is also imperative to recognize that the NFL has enhanced its concussion management based on available scientific data. Hence, recently retired NFL players could have perhaps enjoyed better medical care from more experienced staff who have expertise in managing concussions when they happen.
Delimitation
This study appreciates that CTE can only be conclusively diagnosed at autopsy, as previous findings have demonstrated (Ban et al., 2016). This study, however, will not focus on post-mortem analyses of NFL players’ brains. The study will also not focus on a controversial, subjective case of whether sub concussion can result in CTE due to a lack of measurable and reproducible limits, which often cause difficulties in identifying the most suitable study subjects.
References
Ban, V. S., Madden, C. J., Bailes, J. E., Batjer, H. H., & Lonser, R. R. (2016). The science and questions surrounding chronic traumatic. Neurosurgical Focus, 40(4), 1-10. Web.
Casson, I. R., Viano, D. C., Haacke, E. M., Kou, Z., & Kou, Z. (2014). Is there chronic brain damage in retired NFL players? Neuroradiology, neuropsychology, and neurology examinations of 45 retired players. Sports Health, 6(5), 384–395. Web.
Coughlin, J. M., Wang, Y., Minn, I., Bienko, N., Ambinde, E. B., Peters, M. E.,… Pomper, M. G. (2017). Imaging of glial cell activation and white matter integrity in brains of active and recently retired National Football League players. JAMA Neurology, 74(1), 67-74. Web.
Gavett, B. E., Stern, R. A., & McKee, A. C. (2011). Chronic traumatic encephalopathy: a potential late effect of sport-related concussive and subconcussive head trauma. Clinics in Sports Medicine, 30(1), 179–xi. Web.
Kerr, Z. Y., Evenson, K. R., Rosamond, W. D., Mihalik, J. P., Guskiewicz, K. M., & Marshall, S. W. (2014). Association between concussion and mental health in former collegiate athletes. Injury Epidemiology, 1, 28. Web.
Small, G. W., Kepe, V., Siddarth, P., Ercoli, L. M., Merrill, D. A., Donoghue, N.,… Barrio, J. R. (2013). PET scanning of brain tau in retired National Football League players: Preliminary findings. The American Association for Geriatric Psychiatry, 21(2), 138-144. Web.