Riahi F, Zijdenbos A, Narayanan S, Arnold D, Francis G, Antel J, Evans A C
Department of Neurology and Neurosurgery, Montréal Neurological Institute and Hospital, McGill University, Canada.
Brain. 1998 Jul;121 ( Pt 7):1305-12. doi: 10.1093/brain/121.7.1305.
We hypothesized that a better correlation between MRI and clinical measures of neurological disability using the expanded disability status scale (EDSS) in multiple sclerosis could be obtained by assessing lesion load only in and around the corticospinal tracts, since the EDSS is weighted towards motor and ambulatory deficits. Multiple sclerosis lesions in cerebral MRIs from 39 patients with relapsing-remitting multiple sclerosis were manually painted using a three-dimensional computer display tool and mapped into a standardized three-dimensional coordinate space. Total lesion load was then measured. A mask to expose only the corticospinal tract was extracted from an MRI atlas and used to measure lesion load in the corticospinal tract. To account for the residual anatomical variability among the different MRI volumes after stereotaxic transformation, the corticospinal tract mask was dilated to various degrees and the lesion load remeasured. Spearman's rank correlation coefficient was used to calculate the correlation between the EDSS and total lesion load and corticospinal tract lesion load and between the EDSS subscores and total lesion load and corticospinal tract lesion load. Spearman's rank correlation coefficient between the EDSS and total lesion load was 0.6, probably reflecting the rather broad EDSS range represented in the study. The highest correlation of 0.67 was between the EDSS and corticospinal tract lesion load, dilated with a blurring kernel of 8-10 mm. The pyramidal subscore alone showed a weaker correlation with total lesion load, and with corticospinal tract lesion load, than did the overall EDSS, possibly reflecting the narrow range of disability in these subscores in patients with EDSS scores of 1-6.5. The imperfect correlation between the EDSS and corticospinal tract lesion load suggests that factors other than cerebral T2-weighted lesion volume are important determinants of disability.
我们推测，由于扩展残疾状态量表（EDSS）侧重于运动和行走功能缺陷，通过仅评估皮质脊髓束及其周围的病灶负荷，在多发性硬化症中可使MRI与使用EDSS进行的神经功能残疾临床测量之间获得更好的相关性。使用三维计算机显示工具对39例复发缓解型多发性硬化症患者的脑部MRI中的多发性硬化症病灶进行手动描绘，并将其映射到标准化的三维坐标空间中。然后测量总病灶负荷。从MRI图谱中提取仅暴露皮质脊髓束的掩码，并用于测量皮质脊髓束中的病灶负荷。为了考虑立体定向变换后不同MRI体积之间残留的解剖学变异性，将皮质脊髓束掩码进行不同程度的扩张，并重新测量病灶负荷。使用Spearman等级相关系数来计算EDSS与总病灶负荷、皮质脊髓束病灶负荷之间以及EDSS子分数与总病灶负荷、皮质脊髓束病灶负荷之间的相关性。EDSS与总病灶负荷之间的Spearman等级相关系数为0.6，这可能反映了研究中所代表的EDSS范围相当广泛。EDSS与皮质脊髓束病灶负荷之间的最高相关性为0.67，该皮质脊髓束病灶负荷是用8 - 10毫米的模糊内核进行扩张的。单独的锥体束子分数与总病灶负荷以及皮质脊髓束病灶负荷的相关性，比整体EDSS要弱，这可能反映了EDSS评分为1 - 6.5的患者中这些子分数所代表的残疾范围较窄。EDSS与皮质脊髓束病灶负荷之间不完美的相关性表明，除了脑T2加权病灶体积之外的因素也是残疾的重要决定因素。
