Boston University Alzheimer's Disease Research Center and Boston University CTE Center, Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands.
J Alzheimers Dis. 2022;85(2):675-689. doi: 10.3233/JAD-210379.
Repetitive head impacts (RHI) from contact sports have been associated with cognitive and neuropsychiatric disorders. However, not all individuals exposed to RHI develop such disorders. This may be explained by the reserve hypothesis. It remains unclear if the reserve hypothesis accounts for the heterogenous symptom presentation in RHI-exposed individuals. Moreover, optimal measurement of reserve in this population is unclear and likely unique from non-athlete populations.
We examined the association between metrics of reserve and cognitive and neuropsychiatric functioning in 89 symptomatic former National Football League players.
Individual-level proxies (e.g., education) defined reserve. We additionally quantified reserve as remaining residual variance in 1) episodic memory and 2) executive functioning performance, after accounting for demographics and brain pathology. Associations between reserve metrics and cognitive and neuropsychiatric functioning were examined.
Higher reading ability was associated with better attention/information processing (β=0.25; 95% CI, 0.05-0.46), episodic memory (β=0.27; 95% CI, 0.06-0.48), semantic and phonemic fluency (β=0.24; 95% CI, 0.02-0.46; β=0.38; 95% CI, 0.17-0.59), and behavioral regulation (β=-0.26; 95% CI, -0.48, -0.03) performance. There were no effects for other individual-level proxies. Residual episodic memory variance was associated with better attention/information processing (β=0.45; 95% CI, 0.25, 0.65), executive functioning (β=0.36; 95% CI, 0.15, 0.57), and semantic fluency (β=0.38; 95% CI, 0.17, 0.59) performance. Residual executive functioning variance was associated with better attention/information processing (β=0.44; 95% CI, 0.24, 0.64) and episodic memory (β=0.37; 95% CI, 0.16, 0.58) performance.
Traditional reserve proxies (e.g., years of education, occupational attainment) have limitations and may be unsuitable for use in elite athlete samples. Alternative approaches of reserve quantification may prove more suitable for this population.
接触性运动中的重复性头部撞击（RHI）与认知和神经精神障碍有关。然而，并非所有接触 RHI 的人都会出现此类疾病。这可以用储备假说来解释。储备假说是否可以解释 RHI 暴露个体的异质症状表现尚不清楚。此外，该人群中储备的最佳测量方法尚不清楚，而且可能与非运动员人群不同。
我们研究了 89 名有症状的前美国国家橄榄球联盟运动员的储备指标与认知和神经精神功能之间的关系。
个体水平的替代指标（例如，教育）定义了储备。我们还通过以下方式量化了储备：1）在考虑人口统计学和大脑病理学后，在情景记忆和 2）执行功能表现中，剩余的残余方差。检查了储备指标与认知和神经精神功能之间的关系。
较高的阅读能力与注意力/信息处理（β=0.25；95%置信区间，0.05-0.46）、情景记忆（β=0.27；95%置信区间，0.06-0.48）、语义和语音流畅性（β=0.24；95%置信区间，0.02-0.46；β=0.38；95%置信区间，0.17-0.59）和行为调节（β=-0.26；95%置信区间，-0.48，-0.03）表现较好有关。其他个体水平的替代指标没有影响。剩余的情景记忆方差与注意力/信息处理（β=0.45；95%置信区间，0.25,0.65）、执行功能（β=0.36；95%置信区间，0.15,0.57）和语义流畅性（β=0.38；95%置信区间，0.17,0.59）表现较好有关。剩余的执行功能方差与注意力/信息处理（β=0.44；95%置信区间，0.24,0.64）和情景记忆（β=0.37；95%置信区间，0.16,0.58）表现较好有关。
传统的储备替代指标（例如，受教育年限、职业成就）存在局限性，可能不适合用于精英运动员样本。储备量化的替代方法可能更适合该人群。
