King Regan, Kirton Adam, Zewdie Ephrem, Seeger Trevor A, Ciechanski Patrick, Barlow Karen M
Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
Front Neurol. 2019 May 17;10:451. doi: 10.3389/fneur.2019.00451. eCollection 2019.
Symptoms following a mild traumatic brain injury (mTBI) usually resolve quickly but may persist past 3 months in up to 15% of children. Mechanisms of mTBI recovery are poorly understood, but may involve alterations in cortical neurophysiology. Transcranial Magnetic Stimulation (TMS) can non-invasively investigate such mechanisms, but the time course of neurophysiological changes in mTBI are unknown. To determine the relationship between persistent post-concussive symptoms (PPCS) and altered motor cortex neurophysiology over time. This was a prospective, longitudinal, controlled cohort study comparing children (8-18 years) with mTBI (symptomatic vs. asymptomatic) groups to controls. Cortical excitability was measured using TMS paradigms at 1 and 2 months post injury. The primary outcome was the cortical silent period (cSP). Secondary outcomes included short interval intracortical inhibition (SICI) and facilitation (SICF), and long-interval cortical inhibition (LICI). Generalized linear mixed model analyses were used to evaluate the effect of group and time on neurophysiological parameters. One hundred seven participants (median age 15.1, 57% female) including 78 (73%) with symptomatic PPCS and 29 with asymptomatic mTBI, were compared to 26 controls. Cortical inhibition (cSP and SICI) was reduced in the symptomatic group compared to asymptomatic group and tended to increase over time. Measures of cortical facilitation (SICF and ICF) were increased in the asymptomatic group and decreased over time. TMS was well tolerated with no serious adverse events. TMS-assessed cortical excitability is altered in children following mild TBI and is dependent on recovery trajectory. Our findings support delayed return to contact sports in children even where clinical symptoms have resolved.
轻度创伤性脑损伤（mTBI）后的症状通常会迅速缓解，但在高达15%的儿童中，症状可能会持续超过3个月。mTBI恢复的机制尚不清楚，但可能涉及皮质神经生理学的改变。经颅磁刺激（TMS）可以非侵入性地研究这些机制，但mTBI中神经生理学变化的时间进程尚不清楚。为了确定随时间推移持续性脑震荡后症状（PPCS）与运动皮质神经生理学改变之间的关系。这是一项前瞻性、纵向、对照队列研究，将患有mTBI的儿童（8 - 18岁，有症状组与无症状组）与对照组进行比较。在受伤后1个月和2个月使用TMS范式测量皮质兴奋性。主要结局是皮质静息期（cSP）。次要结局包括短间隔皮质内抑制（SICI）和易化（SICF），以及长间隔皮质抑制（LICI）。使用广义线性混合模型分析来评估组和时间对神经生理学参数的影响。将107名参与者（中位年龄15.1岁，57%为女性）包括78名（73%）有症状性PPCS的患者和29名无症状mTBI患者与26名对照组进行比较。与无症状组相比，有症状组的皮质抑制（cSP和SICI）降低，并且随时间有增加的趋势。无症状组的皮质易化测量值（SICF和ICF）增加，且随时间降低。TMS耐受性良好，无严重不良事件。轻度TBI后的儿童经TMS评估的皮质兴奋性发生改变，且取决于恢复轨迹。我们的研究结果支持即使临床症状已缓解，儿童也应延迟恢复接触性运动。
