Traumatic thoracic ASIA A examinations and potential for clinical trials

Study Design: Retrospective review of prospective database Objectives: To define the variability of neurologic examination and recovery after non-penetrating complete thoracic spinal cord injuries (ASIA A). Background Data: Neurologic examinations after SCI can be difficult and inconsistent. Unlike cervical SCI patients, alterations in thoracic (below T1) complete SCI (ASIA A – based on the ASIA Impairment Scale [AIS]) patients’ exams are based only on sensory testing, thus changes in the neurological level (NL) are determined only by sensory changes. Methods: A retrospective review of the placebo control patients in a multicenter prospective database utilized for the pharmacologic trial of Sygen. Patients were included if they had a complete thoracic SCI on initial evaluation, with completed ASIA examinations at follow-up weeks 4, 8, 16, 26 and 52. Specifically, pin prick (PP) and light touch (LT) were assessed and the absolute change was calculated as the number of spinal levels at a given observation time. Results 3165 patients were initially screened for the Sygen clinical trial, of which 57 were the control placebo patients used in this analysis. Alterations from the baseline exam (PP and LT) were fairly consistent and the median change/recovery in neurologic examination was one spinal level. Across all observations post-baseline, the average change for PP was 1.48 +/- 0.13 (mean +/- SE), and for LT, 1.40 +/-0.13. There were equal proportions of directional changes (none, improved, lost). Conclusions: Changes in a thoracic complete (ASIA A) SCI patient ASIA examination as measured through sensory modalities (PP/LT) are fairly uncommon. The overall examination had only 1-2 level variability across patients, indicating minimal change in the sensory exam over the follow-up period. Stability in the ASIA examination as measured through sensory modalities has thus been demonstrated over time, making it an excellent tool to monitor changes in neurologic function.