The correlation of neurosurgery motor examinations with ISNCSCI motor examinations in patients with spinal cord injury: a multicenter TRACK-SCI study

OBJECTIVE The International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) assessment is the gold standard for evaluation of neurological function after spinal cord injury (SCI). Although it is an invaluable tool for diagnostic and research purposes, it is time consuming and can be impractical in acute injury settings. Clinical neurosurgery motor examinations (NMEs) could serve as an expeditious surrogate for SCI research when ISNCSCI motor examinations are not feasible. The aim of this study was to evaluate the agreement between motor examinations performed by the neurosurgery clinical team and ISNCSCI examiners. METHODS The multicenter prospective Transforming Research and Clinical Knowledge in Spinal Cord Injury (TRACK-SCI) registry was queried to identify patients with recorded neurosurgery and research motor examinations within 24 hours of each other. Pearson correlations and modified Bland-Altman analyses were performed using data from matching upper-extremity, lower-extremity, and combined examinations. Kappa analysis was used to test interrater reliability with respect to determination of American Spinal Injury Association Impairment Scale (AIS) grade. RESULTS There were 72 pairs of matching clinical and research examinations in 63 patients. NME scores were strongly correlated with ISNCSCI motor scores (R = 0.962, p < 0.001). Both upper- and lower-extremity NME scores were strongly correlated with upper- and lower-extremity ISNCSCI motor scores, respectively (R = 0.939, p < 0.001; and R = 0.959, p < 0.001, respectively). In modified Bland-Altman analyses, total, upper-extremity, and lower-extremity NME scores and ISNCSCI motor scores showed low systematic bias and high agreeability (total: bias = 0.3, limit of agreement LoA = 36.6; upper extremity: bias = −0.5, LoA = 17.6; lower extremity: bias = 0.8, LoA = 24.0). There were 66 pairs of examinations that had thorough sensory and rectal examinations for AIS grade calculation. Using kappa analysis to test the interrater reliability of AIS grade calculation using NME versus ISNCSCI motor scores, the authors found a weighted kappa of 0.883 (SE 0.061, 95% CI 0.736–0.976), indicating strong agreement. CONCLUSIONS Overall, this study suggests that ISNCSCI motor scores and NME scores are strongly correlated and highly agreeable. When conducting SCI research, a thorough clinical motor examination may be a useful surrogate when ISNCSCI examinations are missing.