Citation

Dvorak MF, Noonan V, Fallah N, Fisher CG, Rivers CS, Ahn H, Tsai EC, Linassi G, Christie S, Attabib N, Hurlbert RJ, Fourney DR, Johnson MG, Fehlings MG, Drew B, Bailey C, Paquet J, Parent S, Townson A, Ho C, Craven BC, Gagnon D, Tsui D, Fox R, Mac-Thiong JM, Kwon BK. J. Neurotrauma 2014; 31(18): 1540-1547.

Affiliation

818 West 10th Ave, Vancouver, British Columbia, Canada, V5Z 1M9, 604-875-5859 ; Marcel.Dvorak@vch.ca.

Copyright

(Copyright © 2014, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2013.3278

PMID

24811484

Abstract

BACKGROUND: Clinical trials of therapies for acute traumatic spinal cord injury (tSCI) have failed to convincingly demonstrate efficacy in improving neurologic function. Failing to acknowledge the heterogeneity of these injuries and under-appreciating the impact of the most important baseline prognostic variables likely contributes to this translational failure. Our hypothesis was that neurological level and severity of initial injury (measured by ASIA Impairment Scale, AIS) act jointly and are the major determinants of motor recovery. Our objective was to quantify the influence of these variables, when considered together on early motor score recovery following acute tSCI. Materials/Methods: 836 participants from the Rick Hansen Spinal Cord Injury Registry were analyzed for motor score improvement from baseline to follow-up.

RESULTS: In AIS A, B, and C patients, cervical and thoracic injuries displayed significantly different motor score recovery. AIS A patients with thoracic (T2-T10) and thoracolumbar (T11-L2) injuries had significantly different motor improvement. High (C1-C4) and low (C5-T1) cervical injuries demonstrated differences in upper extremity motor recovery in AIS B, C, and D. A hypothetical clinical trial example demonstrated the benefits of stratifying on neurological level and severity of injury.

CONCLUSIONS: Clinically meaningful motor score recovery is predictably related to the neurological level of injury and the severity of the baseline neurological impairment. Stratifying clinical trial cohorts using a joint distribution of these two variables will enhance a study's chance of identifying a true treatment effect and minimize the risk of misattributed treatment effects. Clinical studies should stratify participants based on these factors and record the number of participants and their mean baseline motor scores for each category of this joint distribution as part of the reporting of participant characteristics. Improved clinical trial design is a high priority as new therapies and interventions for tSCI emerge.

Language: en