Brittany A. Snider

Central cord syndrome (CCS) is the most prevalent and debated incomplete spinal cord injury (SCI) syndrome, with its hallmark feature being more pronounced weakness of the upper extremities than of the lower extremities. Varying definitions encapsulate multiple clinical features under the single umbrella term of CCS, complicating evaluation of its frequency, prognosis discussions, and outcomes research. Often, people with CCS are excluded from research protocols, as it is thought to have a favorable prognosis, but the vague nature of CCS raises doubts about the validity of this practice. The objective of this study was to categorize CCS into specific subsets with clear quantifiable differences, to assess whether this would enhance the ability to determine if individuals with CCS or its subsets exhibit distinct neurological and functional outcomes relative to others with incomplete tetraplegia. This study retrospectively reviewed individuals with new motor incomplete tetraplegia from traumatic SCI who enrolled in the Spinal Cord Injury Model Systems (SCIMS) database from 2010 to 2020. Through an assessment of the prevailing criteria for CCS, coupled with data analysis, we used two key criteria, including the severity of distal upper extremity weakness (i.e., hands and fingers) and extent of symmetry, to delineate three CCS subsets: full CCS, unilateral CCS, and borderline CCS. Of the 1490 participants in our sample, 17.5% had full, 25.6% had unilateral, and 9% had borderline CCS, together encompassing >50% of motor incomplete tetraplegia cases. Despite the increased sensitivity and specificity of these subsets compared with existing quantifiable criteria, substantial variability in clinical presentation was still observed. Overall, individuals meeting CCS subset criteria showed a higher likelihood of American Spinal Injury Association (ASIA) Impairment Scale (AIS) D grade than those with motor incomplete tetraplegia without CCS. Upper Extremity Motor Score (UEMS) for those with CCS was lower on admission, a difference that diminished by discharge, whereas their Lower Extremity Motor Score (LEMS) consistently remained higher than for those without CCS. However, these neurological distinctions did not result in significant functional differences, as lower and upper extremity functional outcomes at discharge were mostly similar, with some differences observed within those with AIS D grade. The AIS grade, rather than the diagnosis of CCS, remains the foremost determinant influencing neurological and functional outcomes. We recommend that future studies consider incorporating motor incomplete tetraplegia into their inclusion/exclusion criteria, instead of relying on criteria specific to CCS. Although there remains clinical value in characterizing an injury pattern as CCS and perhaps using the different subsets to better characterize the impairments, it does not appear to be a useful research criterion.

Background: Successful utilization of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) requires a comprehensive understanding of its rules, terminology, and several complex concepts. There have been no studies investigating classification accuracy since the newest ISNCSCI revision (2019). Objectives: To evaluate classification accuracy of SCI professionals using the 2019 ISNCSCI edition, identify common mistakes and areas of confusion, and assess associations between experience in ISNCSCI classification and performance. Methods: Members of the International Spinal Cord Society (ISCoS) and attendees of the ISCoS Annual Scientific Meeting 2021 were invited to complete an online survey that included six ISNCSCI cases to classify. Results: A total of 107 persons completed the survey, with overall classification accuracy of 74.6%. Accuracy was highest for injury completeness (95.3%) and sensory level (91.1%) and lowest for motor zone of partial preservation (ZPP; 54.7%) and ASIA Impairment Scale (AIS) grade (57.3%). Newer concepts, including the appropriate documentation of non-SCI conditions and classification of ZPP in incomplete injuries, contributed to several common errors. There was a significant association between overall classification accuracy and self-rated experience in the ISNCSCI classification ( p = .017). Experience with the ISNCSCI examination, experience in SCI medicine, and occupation were not found to be significantly associated with overall classification accuracy. Conclusion: Classification accuracy of an international cohort of SCI professionals was modest but greater than previous reports. Knowledge deficits about the 2019 ISNCSCI updates are prevalent and contribute to common classification errors. Further training in the utilization of the ISNCSCI is needed.