Boston University Alzheimer's Disease and CTE Centers, Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
Brain Imaging Behav. 2020 Oct;14(5):1419-1429. doi: 10.1007/s11682-019-00060-4.
The long-term neurologic consequences of exposure to repetitive head impacts (RHI) are not well understood. This study used magnetic resonance spectroscopy (MRS) to examine later-life neurochemistry and its association with RHI and clinical function in former National Football League (NFL) players. The sample included 77 symptomatic former NFL players and 23 asymptomatic individuals without a head trauma history. Participants completed cognitive, behavior, and mood measures. N-acetyl aspartate, glutamate/glutamine, choline, myo-inositol, creatine, and glutathione were measured in the posterior (PCG) and anterior (ACG) cingulate gyrus, and parietal white matter (PWM). A cumulative head impact index (CHII) estimated RHI. In former NFL players, a higher CHII correlated with lower PWM creatine (r = -0.23, p = 0.02). Multivariate mixed-effect models examined neurochemical differences between the former NFL players and asymptomatic individuals without a history of head trauma. PWM N-acetyl aspartate was lower among the former NFL players (mean diff. = 1.02, p = 0.03). Between-group analyses are preliminary as groups were recruited based on symptomatic status. The ACG was the only region associated with clinical function, including positive correlations between glutamate (r = 0.32, p = 0.004), glutathione (r = 0.29, p = 0.02), and myo-inositol (r = 0.26, p = 0.01) with behavioral/mood symptoms. Other positive correlations between ACG neurochemistry and clinical function emerged (i.e., behavioral/mood symptoms, cognition), but the positive directionality was unexpected. All analyses controlled for age, body mass index, and education (for analyses examining clinical function). In this sample of symptomatic former NFL players, there was a direct effect between RHI and reduced cellular energy metabolism (i.e., lower creatine). MRS neurochemicals associated with neuroinflammation also correlated with behavioral/mood symptoms.
反复头部撞击（RHI）暴露的长期神经后果尚不清楚。本研究使用磁共振波谱（MRS）检查了前国家橄榄球联盟（NFL）运动员的晚年神经化学及其与 RHI 和临床功能的关系。该样本包括 77 名有症状的前 NFL 球员和 23 名没有头部创伤史的无症状个体。参与者完成了认知、行为和情绪测量。在后（PCG）和前（ACG）扣带回以及顶叶白质（PWM）中测量了 N-乙酰天冬氨酸、谷氨酸/谷氨酰胺、胆碱、肌醇、肌酸和谷胱甘肽。累积头部撞击指数（CHII）估计了 RHI。在前 NFL 球员中，较高的 CHII 与较低的 PWM 肌酸相关（r=-0.23，p=0.02）。多元混合效应模型检查了前 NFL 球员和无头部创伤史的无症状个体之间的神经化学差异。前 NFL 球员的 PWM N-乙酰天冬氨酸较低（平均差异=1.02，p=0.03）。由于根据症状状态招募了两组，因此组间分析只是初步的。ACG 是唯一与临床功能相关的区域，包括谷氨酸（r=0.32，p=0.004）、谷胱甘肽（r=0.29，p=0.02）和肌醇（r=0.26，p=0.01）与行为/情绪症状之间存在正相关。ACG 神经化学与临床功能之间还出现了其他正相关（即行为/情绪症状、认知），但正相关方向出乎意料。所有分析均控制了年龄、体重指数和教育程度（用于检查临床功能的分析）。在这个有症状的前 NFL 球员样本中，RHI 与细胞能量代谢降低（即肌酸降低）之间存在直接影响。与神经炎症相关的 MRS 神经化学物质也与行为/情绪症状相关。
