Validation of a Myelomeningocele Severity Scale

Abstract

Background: Myelomeningocele as a neural tube defect occurs in varying levels of severity. The ambulatory function outcome is well correlated with the MMC spectrum by existing spina bifida scores. None of the existing scores predict survival or study the effect of more than two severity markers. Objective: To validate the proposed myelomeningocele severity scale as a predictor of survival at the 3 year end point. Methods: This was a cross sectional institutional study that recruited 153 patients from a high volume center. The study duration was between 2010-2014, during which time data on motor function, presence or absence of a kyphus deformity, hydrocephalus, ventricular CSF WBC count, bladder function, syndromic features and Chiari II symptomatology were collected and analysed. Biostatistical analysis was done using the STATA 14 program. Results are presented in form of tables, graphs, pie charts and diagrams. Results: A total of 153 patient charts were reviewed. The minimum and maximum scores were 7 and 24 respectively on the myelomeningocele severity scale. The new scale was found to be as reliable as the SBNS for prediction of future mobility (Pearson Correlation = -0.74). The 3 year overall mortality rate was 15% (24 patients). Thirteen of these deaths occurred in the high risk category (a score of 21-30), 11 from the intermediate risk category (12-20) and 1 within the low risk category (7-11). Low and intermediate risk groups had longer survival as opposed the high risk group patients (2/3 of the high risk mortalities occurred within the first year of life). Conclusion: The myelomeningocele severity scale is a reliable predictor of survival 3 years post MMC closure. It is also as reliable as the already existing SBNS scale for predicting the motor outcome at 3 years post MMC repair.