There is growing public concern about neurodegenerative changes (e.g., Chronic Traumatic Encephalopathy) that may occur chronically following clinically apparent and clinically silent (i.e., sub-concussive blows) pediatric mild traumatic brain injury (pmTBI). However, there are currently no biomarkers that clinicians can use to objectively diagnose patients or predict those who may struggle to recover. Non-invasive neuroimaging, electrophysiological and neuromodulation biomarkers have promise for providing evidence of the so-called “invisible wounds” of pmTBI. Our systematic review, however, belies that notion, identifying a relative paucity of high-quality, clinically impactful, diagnostic or prognostic biomarker studies in the sub-acute injury phase (36 studies on unique samples in 28 years), with the majority focusing on adolescent pmTBI. Ultimately, well-powered longitudinal studies with appropriate control groups, as well as standardized and clearly-defined inclusion criteria (time post-injury, injury severity and past history) are needed to truly understand the complex pathophysiology that is hypothesized (i.e., still needs to be determined) to exist during the acute and sub-acute stages of pmTBI and may underlie post-concussive symptoms.

有越来越多的关于神经退行性改变（例如，慢性创伤性脑病），公众关注的是可能在临床上明显且临床上无声（即亚震荡性打击）小儿轻度颅脑外伤（pmTBI）之后发生。但是，目前没有临床医生可用来客观诊断患者或预测可能难以康复的生物标志物。非侵入性神经影像，电生理和神经调节生物标志物有望为pmTBI的所谓“无形伤口”提供证据。但是，我们的系统评价掩盖了这一概念，即在亚急性损伤阶段确定了相对较少的高质量，具有临床影响力，诊断性或预后性的生物标志物研究（28年中有36项针对独特样本的研究），其中大多数关注于青少年pmTBI。最终，通过适当的对照组，进行有力的纵向研究，