Abstract：
Assessing the extent of the intramedullary lesion after spinal cord injury (SCI) might help to improve prognostication. However, because the neurological level of injury impacts the recovery potential of SCI patients, the question arises whether lesion size parameters and predictive models based on those parameters are affected as well. In this retrospective observational study, the extent of the intramedullary lesion between individuals who sustained cervical and thoracolumbar SCI was compared, and its relation to clinical recovery was assessed. In total, 154 patients with subacute SCI (89 individuals with cervical lesions and 65 individuals with thoracolumbar lesions) underwent conventional clinical magnetic resonance imaging 1 month after injury and clinical examination at 1 and 12 months. The morphology of the focal lesion within the spinal cord was manually assessed on the midsagittal slice of T2-weighted magnetic resonance images and compared between cervical and thoracolumbar SCI patients, as well as between patients who improved at least one American Spinal Injury Association Impairment Scale (AIS) grade (converters) and patients without AIS grade improvement (nonconverters). The predictive value of lesion parameters including lesion length, lesion width, and preserved tissue bridges for predicting AIS grade conversion was assessed using regression models (conditional inference tree analysis). Lesion length was two times longer in thoracolumbar compared with cervical SCI patients (F = 39.48, p < 0.0001), whereas lesion width and tissue bridges width did not differ. When comparing AIS grade converters and nonconverters, converters showed a smaller lesion length (F = 5.46, p = 0.021), a smaller lesion width (F = 13.75, p = 0.0003), and greater tissue bridges (F = 12.87, p = 0.0005). Using regression models, tissue bridges allowed more refined subgrouping of patients in AIS groups B, C, and D according to individual recovery profiles between 1 month and 12 months after SCI, whereas lesion length added no additional information for further subgrouping. This study characterizes differences in the anteroposterior and craniocaudal lesion extents after SCI. The two times greater lesion length in thoracolumbar compared with cervical SCI might be related to differences in the anatomy, biomechanics, and perfusion between the cervical and thoracic spines. Preserved tissue bridges were less influenced by the lesion level while closely related to the clinical impairment. These results highlight the robustness and utility of tissue bridges as a neuroimaging biomarker for predicting the clinical outcome after SCI in heterogeneous patient populations and for patient stratification in clinical trials.
摘要：
评估脊髓损伤（SCI）后髓内病变的程度可能有助于改善预后。然而,由于神经损伤水平（NLI）影响SCI患者的恢复潜力，出现了一个问题，即病变大小参数和基于这些参数的预测模型是否也受到影响。在这项回顾性观察研究中，比较了颈椎和胸腰椎SCI患者之间的髓内病变程度,并评估了其与临床恢复的关系.154例亚急性SCI患者（89例宫颈病变和65例胸腰椎病变）在受伤后1个月接受了常规临床磁共振成像（MRI），并在1和12个月进行了临床检查。在T2加权MR图像的中矢状切片上手动评估脊髓内局灶性病变的形态，并在颈椎和胸腰椎SCI患者之间以及在至少一个美国脊髓损伤协会损害量表（AIS）等级（转换器）和没有AIS等级改善的患者（非转换器）之间进行比较。病变参数的预测价值，包括病变长度，病变宽度,使用回归模型（条件推断树分析）评估用于预测AIS等级转换的保留组织桥。胸腰段病变长度比宫颈SCI患者长两倍(F=39.48,p<0.0001),而病变宽度和组织桥宽度没有差异。当比较AIS级转换器和非转换器时，转换器显示病变长度较小（F=5.46，p=0.021），较小的病变宽度（F=13.75，p=0.0003）和较大的组织桥（F=12.87，p=0.0005）。使用回归模型，组织桥允许根据SCI后1个月至12个月的个体恢复情况对异质性患者群体进行更精细的分组,而病变长度没有增加进一步分组的额外信息.这项研究描述了SCI后前后和颅尾病变程度的差异。胸腰段病灶长度比宫颈脊髓损伤长两倍，可能与解剖结构的差异有关。生物力学,颈椎和胸椎之间的灌注。保留的组织桥受病变水平的影响较小，而与临床损害密切相关。这些结果强调了组织桥作为神经影像学生物标志物的鲁棒性和实用性，用于预测异质性患者人群中SCI后的临床结果以及临床试验中的患者分层。
