The international standards for neurological classification of spinal cord injury: relationship between S4-5 dermatome testing and anorectal testing
Study design:Prospective cross-sectional multicenter study.Objective:To evaluate the correlation, sensitivity, specificity and predictive values of S4-5 dermatome and the anorectal examination for determination of sacral sparing in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) examination.Setting:Two tertiary hospitals that specialize in pediatric spinal cord injuries.Methods:In all, 189 patients who were at minimum 3 month after spinal cord injury participated in complete ISNCSCI examinations. All examiners completed training for the proper completion of the ISNCSCI examination. Correlations and sensitivity/specificity analyses were conducted between S4-5 dermatome testing and the anorectal examination. Results were analyzed by age of patient, examiner, tetraplegia/paraplegia classification and injury level (T10-S3, L1-S3 and S3).Results:The correlation between S4-5 dermatome and anorectal sensation was moderate (0.62, P<0.001). Using the anorectal examination as the gold standard, the sensitivity of S4-5 testing was 0.60 (0.49, 70) and specificity was 0.96 (0.90, 0.99). No single age group, tester, level, or type of injury differed from the overall result.Conclusion:In the pediatric population, the correlation between S4-5 and anorectal sensation was lower than anticipated. The sensitivity of 0.62 for S4-5 testing and diminished sensation between T10 and S3 suggests that anorectal testing may either be a more sensitive representation of S4-5 function or activate an alternative neuronal pathway that is perceived by the patient. Further investigation into the validity of the sacral sparing components of the ISNCSCI examination is warranted.