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

Abstract

Objective: To assess the patterns of sacral sparing and recovery in newly injured persons with traumatic spinal cord injury (SCI).

Design: Retrospective analysis of data from the national Spinal Cord Injury Model Systems (SCIMS) database for patients enrolled from January 2011 to February 2015.

Setting: SCIMS centers.

Participants: Individuals (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.

Interventions: Not applicable.

Main outcome measures: International Standards for Neurological Classification of Spinal Cord Injury examination results at admission and follow-up (discharge or 1y, or both).

Results: Conversion 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.

Conclusions: The 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.

Keywords: Classification; Neurologic examination; Prognosis; Rehabilitation; Spinal cord injuries.