PURPOSE Longer latency of postural response in multiple sclerosis (MS) may be linked to imbalance and increased likelihood of falls. It may be caused by the compromised microstructural integrity in the spinal cord, as evidenced by slowed somatosensory conduction in the spinal cord. Thus, the purpose of this study is to investigate the correlation between latency of postural responses and microstructural integrity of the cervical spinal cord, the region particularly related to the disease severity in MS, using diffusion tensor imaging (DTI) metrics. METHODS Seventeen persons with MS with mild-to-moderate disease severity were enrolled in this study. Postural response latencies of each patient were measured using electromyography of the tibialis anterior muscle (TA) and gastrocnemius muscle (GN) in response to surface perturbations. Cervical spinal cord DTI images were obtained from each patient. DTI mean, radial, axial diffusivity, and fractional anisotropy (FA) were measured between segments C4 and C6. Correlations of DTI metrics with postural response latencies, expanded disability status scale (EDSS) scores, and 25-foot walk (T25FW) were assessed using the Spearman's rank correlation coefficient at α = 0.05. RESULTS Lower FA was significantly correlated with longer latencies measured on right TA in response to forward postural perturbations (r = -0.51, p = .04). DTI metrics showed no significant correlations with EDSS scores (r = -0.06-0.09, p = .73-0.95) or T25FW (r = -0.1-0.14, p = .6-0.94). DTI metrics showed no significant differences between subjects with and without spinal cord lesions (p = .2-0.7). CONCLUSIONS Our results showed a significant correlation between lower FA in the cervical spinal cord and longer latencies measured on right TA in response to forward postural perturbations in persons with MS, suggesting that impaired cervical spinal cord microstructure assessed by DTI may be associated with the delayed postural responses.

中文翻译：

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多发性硬化症患者脊髓弥散张量成像与体位反应潜伏期的相关性：一项初步研究。

目的在多发性硬化症（MS）中较长的姿势反应潜伏期可能与失衡和跌倒的可能性增加有关。这可能是由于脊髓微结构完整性受损所致，如脊髓中体感传导减慢所证明的那样。因此，本研究的目的是使用弥散张量成像（DTI）指标研究姿势反应潜伏期与子宫颈脊髓微结构完整性之间的相关性，该区域特别与MS中的疾病严重性有关。方法本研究招募了17名轻度至中度疾病严重程度的MS患者。使用胫骨前肌（TA）和腓肠肌（GN）的肌电图对表面扰动进行测量，测量每位患者的姿势反应潜伏期。从每位患者获得宫颈脊髓DTI图像。在段C4和C6之间测量了DTI平均值，径向，轴向扩散率和分数各向异性（FA）。使用Spearman等级相关系数α= 0.05评估DTI指标与姿势反应潜伏期，扩大的残疾状态量表（EDSS）得分和25英尺步行（T25FW）的相关性。结果较低的FA与右TA上测得的更长的潜伏期显着相关，以响应前向姿势扰动（r = -0.51，p = .04）。DTI指标显示与EDSS分数（r = -0.06-0.09，p = .73-0.95）或T25FW（r = -0.1-0.14，p = 0.6-0.94）没有显着相关性。DTI指标显示有和没有脊髓损伤的受试者之间无显着差异（p = .2-0.7）。