Ambulatory function in motor incomplete spinal cord injury: a magnetic resonance imaging study of spinal cord edema and lower extremity muscle morphometry

Abstract

Study Design This research utilized a cross-sectional design. Objectives Spinal cord edema length has been measured with T2-weighted sagittal MRI to predict motor recovery following spinal cord injury. The purpose of our study was to establish the correlational value of axial spinal cord edema using T2-weighted MRI. We hypothesized a direct relationship between the size of damage on axial MRI and walking ability, motor function, and distal muscle changes seen in motor incomplete spinal cord injury (iSCI). Setting University based laboratory in Chicago, IL USA. Methods Fourteen participants with iSCI took part in the study. Spinal cord axial damage ratios were assessed using axial T2-weighted MRI. Walking ability was investigated using the 6-minute walk test and daily stride counts. Maximum plantarflexion torque was quantified using isometric dynomometry. Muscle fat infiltration (MFI) and relative muscle cross sectional area (rmCSA) were quantified using fat/water separation magnetic resonance imaging. Results Damage ratios were negatively correlated with distance walked in 6 minutes, average daily strides, and maximum plantarflexion torque, and a negative linear trend was found between damage ratios and lower leg rmCSA. While damage ratios were not significantly correlated with MFI, we found significantly higher MFI in the wheelchair user participant group compared to community walkers. Conclusions Damage ratios may be useful in prognosis of motor recovery in spinal cord injury. The results warrant a large multi-site research study to investigate the value of high-resolution axial T2-weighted imaging to predict walking recovery following motor incomplete spinal cord injury.

Establishing the inter-rater reliability of spinal cord damage manual measurement using magnetic resonance imaging

“…This project was a retrospective analysis of MRI data from published studies [5,8,19]. It was approved by Northwestern University and Regis University Institutional Review Boards.…”

“…Images were provided from previous research in which trained personnel transferred participants to a supine position on the scanner bed [5]. MRI was performed with a 3.0 T Siemens (Munich, Germany).…”

“…Rather, the ISNCSCI examination captures gross residual function secondary to the injury [4]. This classification system is subject to variability due to the complex nature of neurological injury [4,5]. As a result, the supplementation of other objective measures are warranted to accompany, if not enhance, the present classification system.…”

“…Presently, T 2 -weighted magnetic resonance imaging (MRI) is the recommended imaging modality for viewing the specific pathological features of the injured spinal cord [6]. Edema is commonly observed on T 2 -weighted MRI as an irregularly shaped characterization of hyperintensity to indicate areas of the damaged cord [5]. While a variety of measures for quantifying the extent of edema have been reported [5,[7][8][9][10][11][12][13][14][15][16] and associated with functional recovery [5,7,8], more evidence is needed to establish the psychometric properties of these measurements.…”

“…Midsagittal tissue bridge (MTB) measures have emerged as a promising approach for functional prognosis [12,19]. The axial damage ratio (ADR) is a novel measure used to capture the two-dimensional extent of edema within the cord [5]. Edema volume is calculated using consecutive axial slices through the damage.…”