Patterns of Sacral Sparing Components on Neurologic Recovery in Newly Injured Persons With Traumatic Spinal Cord Injury

Abstract

ObjectiveTo assess the patterns of sacral sparing and recovery in newly injured persons with traumatic spinal cord injury (SCI). DesignRetrospective analysis of data from the national Spinal Cord Injury Model Systems (SCIMS) database for patients enrolled from January 2011 to February 2015. SettingSCIMS centers. ParticipantsIndividuals (N=1738; age ≥16y) with traumatic SCI admitted to rehabilitation within 30 days after injury with follow-up at discharge, at 1 year, or both. InterventionsNot applicable. Main Outcome MeasuresInternational Standards for Neurological Classification of Spinal Cord Injury examination results at admission and follow-up (discharge or 1y, or both). ResultsConversion from an initial American Spinal Injury Association Impairment Scale (AIS) grade A to incomplete status was 20% at rehabilitation discharge and 27.8% at 1 year, and was greater in cervical and low paraplegia levels (T10 and below) than in high paraplegia level injuries (T1-9). Conversion from AIS B to motor incomplete was 33.9% at discharge and 53.6% at 1 year, and the initial sparing of all sacral sensory components was correlated with the greatest conversion to motor incomplete status at discharge and at 1 year. For patients with initial AIS C, the presence of voluntary anal contraction (VAC) in association with other sacral sparing was most frequently observed to improve to AIS D status at discharge. However, the presence of VAC alone as the initial sacral sparing component had the poorest prognosis for recovery to AIS D status. At follow-up, regaining sacral sparing components correlated with improvement in conversion for patients with initial AIS B and C. ConclusionsThe components of initial and follow-up sacral sparing indicated differential patterns of neurologic outcome in persons with traumatic SCI. The more sacral components initially spared, the greater the potential for recovery; and the more sacral components gained, the greater the chance of motor recovery. Consideration of whether VAC should remain a diagnostic criterion sufficient for motor incomplete classification in the absence of other qualifying sublesional motor sparing is recommended.