From the Department of Radiology (A.E.G.-Y., K.X.C., D.E., K.H.), Montefiore Medical Center, Bronx, New York.
Department of Epidemiology and Population Health (K.Y.), Albert Einstein College of Medicine, Bronx, New York.
AJNR Am J Neuroradiol. 2018 Oct;39(10):1821-1826. doi: 10.3174/ajnr.A5769. Epub 2018 Sep 6.
Neurodegeneration after mild traumatic brain injury may manifest as decreasing regional brain volume that evolves from months to years following mild traumatic brain injury and is associated with worse clinical outcomes. We hypothesized that quantitative brain volume derived from CT of the head, performed for clinical indications during routine care, would change with time and provide insights into the putative neuroinflammatory response to mild traumatic brain injury.
We searched the electronic medical record of our institution for NCCTs of the head performed in patients with mild traumatic brain injury and included those who also underwent NCCTs of the head 1 month to 1 year before and after mild traumatic brain injury for an indication unrelated to trauma. Controls underwent 3 sequential NCCTs of the head with indications unrelated to trauma. The whole-brain and intracranial volume groups were computed using ITK-SNAP. Brain volumes normalized to intracranial volumes were compared across time points using the Wilcoxon signed-rank test.
We identified 48 patients from 2005 to 2015 who underwent NCCTs of the head in the emergency department for mild traumatic brain injury and had NCCTs of the head performed both before and after mild traumatic brain injury. Median normalized brain volumes significantly decreased on the follow-up study post-mild traumatic brain injury (0.86 versus 0.84, < .001) and were similar compared with pre-mild traumatic brain injury studies (0.87 versus 0.86, = .927). There was no significant difference between normalized brain volumes in the 48 controls.
A decrease in brain volume following mild traumatic brain injury is detectable on CT and is not seen in similar patients with non-mild traumatic brain injury during a similar timeframe. Given the stability of brain volume before mild traumatic brain injury, CT volume loss may represent the subtle effects of neurodegeneration.
轻度创伤性脑损伤后的神经退行性变可能表现为局部脑体积减少，这种变化从轻度创伤性脑损伤后数月到数年逐渐发展，并与更差的临床结局相关。我们假设，在常规护理中出于临床指征进行的头部 CT 定量脑体积会随时间发生变化，并能深入了解轻度创伤性脑损伤后的潜在神经炎症反应。
我们在我院电子病历中搜索了因轻度创伤性脑损伤而接受头部 NCCT 的患者，并纳入了那些在轻度创伤性脑损伤前 1 个月至 1 年后，以及因与创伤无关的指征而接受头部 NCCT 的患者。对照组患者因与创伤无关的指征而接受了 3 次连续的头部 NCCT。全脑和颅内体积使用 ITK-SNAP 进行计算。使用 Wilcoxon 符号秩检验比较各时间点的脑体积与颅内体积的比值。
我们从 2005 年至 2015 年期间确定了 48 名在急诊科因轻度创伤性脑损伤接受头部 NCCT 的患者，他们在轻度创伤性脑损伤前后都接受了头部 NCCT。与轻度创伤性脑损伤后随访研究相比，随访研究中正常化脑体积明显减少（0.86 对 0.84， <.001），与轻度创伤性脑损伤前研究相比也相似（0.87 对 0.86， =.927）。48 名对照组患者的正常化脑体积无显著差异。
轻度创伤性脑损伤后 CT 上可检测到脑体积减少，而在类似时间段内患有非轻度创伤性脑损伤的相似患者中则未观察到这种现象。鉴于轻度创伤性脑损伤前脑体积的稳定性，CT 体积损失可能代表神经退行性变的微妙影响。
