Lesion characteristics are associated with bowel, bladder, and overall independence following cervical spinal cord injury

There is a growing global interest in quantifying spinal cord lesions and spared neural tissue using magnetic resonance imaging (MRI) in individuals with spinal cord injury (SCI). The primary objective of this study was to assess the relationships between spinal cord lesion characteristics assessed on MRI and bowel, bladder, and overall independence following SCI. Retrospective, exploratory study. 93 individuals with cervical SCI who were enrolled in a local United States Model Systems SCI database from 2010 to 2017. Clinical and MRI data were obtained for potential participants, and MRIs of eligible participants were analyzed. Explanatory variables, captured on MRIs, included intramedullary lesion length (IMLL), midsagittal ventral tissue bridge width (VTBW), midsagittal dorsal tissue bridge width (DTBW), and axial damage ratio (ADR). Bowel and bladder management scale of the Functional Independence Measure (FIM) and FIM total motor score. When accounting for all four variables, only ADR was significantly associated with bowel independence (OR = 0.970, 95% CI: 0.942–0.997, P = 0.030), and both ADR and IMLL were strongly associated with bladder independence (OR = 0.967, 95% CI: 0.936–0.999, P = 0.046 and OR = 0.948, 95% CI: 0.919–0.978, P = 0.0007, respectively). 32% of the variation in overall independence scores were explained by all four predictive variables, but only ADR was significantly associated with overall independence after accounting for all other predictive variables (<i>β</i> = −0.469, 95% CI: −0.719, −0.218, P = 0.0004). Our results suggest that the MRI-measured extent of spinal cord lesion may be predictive of bowel, bladder, and overall independence following cervical SCI.

当前全球学界对通过磁共振成像（MRI）量化脊髓损伤（SCI）患者的脊髓病变与残存神经组织的关注度与日俱增。本研究旨在评估脊髓损伤后，MRI评估所得的脊髓病变特征与患者肠道、膀胱功能及整体独立性之间的关联。本研究为回顾性探索性研究，研究对象为2010年至2017年间纳入美国当地模型系统脊髓损伤数据库的93名颈脊髓损伤患者。研究人员收集了潜在受试者的临床与MRI数据，并对符合入组标准的受试者的MRI影像展开分析。从MRI影像中提取的解释变量包括：髓内病变长度（IMLL）、矢状位腹侧组织桥宽度（VTBW）、矢状位背侧组织桥宽度（DTBW）以及轴向损伤比率（ADR）。结局指标涵盖功能独立性评定量表（FIM）的肠道、膀胱管理分项得分，以及FIM运动总得分。在纳入全部四个变量进行多因素分析后，仅轴向损伤比率（ADR）与肠道独立性存在显著关联（优势比[OR]=0.970，95%置信区间[CI]：0.942–0.997，P=0.030）；而轴向损伤比率（ADR）与髓内病变长度（IMLL）均与膀胱独立性存在显著关联（OR=0.967，95%CI：0.936–0.999，P=0.046；OR=0.948，95%CI：0.919–0.978，P=0.0007）。全部四个预测变量可解释整体独立性得分32%的变异量，但在控制其余所有预测变量后，仅轴向损伤比率（ADR）与整体独立性存在显著关联（β=-0.469，95%CI：-0.719，-0.218，P=0.0004）。本研究结果提示，通过MRI测量的脊髓病变程度可用于预测颈脊髓损伤患者术后的肠道、膀胱功能及整体独立性水平。