Department of Geriatric Psychiatry, Psychiatric Hospital Zurich, University of Zurich, Zurich, Switzerland.
Department of Neurology, University Hospital Zurich, Zurich, Switzerland.
Neurodegener Dis. 2020;20(1):2-11. doi: 10.1159/000508098. Epub 2020 Jul 1.
Traumatic brain injury (TBI) is the most relevant external risk factor for dementia and a major global health burden. Mild TBI (mTBI) contributes to up to 90% of all TBIs, and the classification "mild" often misrepresents the patient's burden who suffer from neuropsychiatric long-term sequelae. Magnetic resonance spectroscopy (MRS) allows in vivo detection of compromised brain metabolism although it is not routinely used after TBI.
Thus, we performed a systematic review and meta-analysis to elucidate if MRS has the potential to identify changes in brain metabolism in adult patients after a single mTBI with a negative routine brain scan (CCT and/or MRI scan) compared to aged- and sex-matched healthy controls (HC) during the acute or subacute postinjury phase (≤90 days after mTBI).
A comprehensive literature search was conducted from the first edition of electronic databases until January 31, 2020. Group analyses were performed per metabolite using a random-effects model.
Four and 2 out of 5,417 articles met the inclusion criteria for the meta-analysis and systematic review, respectively. For the meta-analysis, 50 mTBI patients and 51 HC with a mean age of 31 and 30 years, respectively, were scanned using N-acetyl-aspartate (NAA), a marker for neuronal integrity. Glutamate (Glu), a marker for disturbed brain metabolism, choline (Cho), a marker for increased cell membrane turnover, and creatine (Cr) were used in 2 out of the 4 included articles. Regions of interests were the frontal lobe, the white matter around 1 cm above the lateral ventricles, or the whole brain. NAA was decreased in patients compared to HC with an effect size (ES) of -0.49 (95% CI -1.08 to 0.09), primarily measured in the frontal lobe. Glu was increased in the white matter in 22 mTBI patients compared to 22 HC (ES 0.79; 95% CI 0.17-1.41). Cho was decreased in 31 mTBI patients compared to 31 HC (ES -0.31; 95% CI -0.81 to 0.19). Cr was contradictory and, therefore, potentially not suitable as a reference marker after mTBI.
MRS pinpoints changes in posttraumatic brain metabolism that correlate with cognitive dysfunction and, thus, might possibly help to detect mTBI patients at risk for unfavorable outcome or posttraumatic neurodegeneration early.
创伤性脑损伤（TBI）是痴呆症的最重要外部风险因素，也是一个主要的全球健康负担。轻度 TBI（mTBI）占所有 TBI 的 90%以上，而“轻度”的分类往往会对患有神经精神长期后遗症的患者造成负担。磁共振波谱（MRS）允许在体内检测到受损的脑代谢，尽管在 TBI 后并未常规使用。
因此，我们进行了系统评价和荟萃分析，以阐明 MRS 是否有可能在单次 mTBI 后识别出急性或亚急性损伤期（mTBI 后≤90 天）内，与年龄和性别匹配的健康对照组（HC）相比，常规脑扫描（CCT 和/或 MRI 扫描）呈阴性的成年患者的脑代谢变化。
从电子数据库的第一版开始进行全面的文献检索，直至 2020 年 1 月 31 日。使用随机效应模型对每个代谢物进行组分析。
4 篇和 2 篇共 5417 篇文章符合荟萃分析和系统综述的纳入标准。对于荟萃分析，50 名 mTBI 患者和 51 名 HC 接受了扫描，平均年龄分别为 31 岁和 30 岁，使用 N-乙酰天冬氨酸（NAA）作为神经元完整性的标志物。谷氨酸（Glu），一种代表脑代谢紊乱的标志物，胆碱（Cho），一种代表细胞膜周转率增加的标志物，以及肌酸（Cr），这三种标志物在纳入的 4 篇文章中的 2 篇中使用。感兴趣的区域是额叶，距侧脑室上方 1 厘米的白质，或整个大脑。与 HC 相比，NAA 在患者中减少，其效应大小（ES）为-0.49（95%CI-1.08 至 0.09），主要在额叶中测量。与 22 名 HC 相比，22 名 mTBI 患者的白质中 Glu 增加（ES 0.79；95%CI 0.17-1.41）。与 31 名 HC 相比，31 名 mTBI 患者的 Cho 减少（ES-0.31；95%CI-0.81 至 0.19）。Cr 存在矛盾，因此可能不适合作为 mTBI 后的参考标志物。
MRS 指出了创伤后脑代谢的变化，这些变化与认知功能障碍相关，因此可能有助于早期检测有不良预后或创伤后神经退行性变风险的 mTBI 患者。
