Clinical Sciences/Health Conditions
Natan Bensoussan, MD, MSc candidate
Physiatrist
Université de Montréal / Hôpital du Sacré-Cœur de Montréal
Montreal, Quebec, Canada
Andréane Richard-Denis, MD, MSc
Physiatrist, Principal Investigator
Université de Montréal / Hôpital du Sacré-Cœur de Montréal / Centre de recherche interdisciplinaire en réadaptation du Montreal métropolitain
Montreal, Quebec, Canada
Jean-Marc Mac-Thiong, MD, PhD
Orthopedic Surgeon, Principal Investigator
Université de Montréal / Hôpital du Sacré-Cœur de Montréal / Centre Hospitalier Universitaire Sainte-Justine
Montreal, Quebec, Canada
Sacral function is central to neurological prognosis after spinal cord injury (SCI), yet standard assessment using digital rectal examination (DRE) may miss subclinical sacral function. We developed a novel point-of-care electrophysiological assessment (ElectroSacroGram, ESG) that detects sacral sensory, or motor responses missed on DRE. Whether these findings hold prognostic value is unknown. This study evaluated whether subclinical sacral preservation is associated with improved neurological recovery.
Design:
A prospective pilot matched-cohort study on motor-complete SCI patients (AIS A/B) was conducted at a Level-1 trauma center (March 2024-October 2025). Five patients with subclinical sacral function (ESG-positive, DRE-negative for voluntary motor or sensory parameters) were matched to seven controls based on neurological level of injury and AIS grade. Outcomes included AIS conversion, change in total motor score, and recovery of sacral function at 6-week follow-up. Exploratory statistics included Fisher’s exact and Mann–Whitney U tests.
Results:
AIS conversion occurred in 4/5 subclinical patients (80%) compared to 2/7 controls (28.6%) (p=0.24). Median total motor score change was +2 in subclinical patients and 0 in controls (p=0.80). Sacral function returned in 40% of subclinical patients and 14% of controls (p=0.52). One patient showed worsening motor score but AIS B to D conversion, suggesting a phenotype of silent sacral sparing, in which ESG identifies early sacral pathway preservation not reflected by DRE or motor score. The incidence of subclinical sacral preservation among motor-complete patients was 20%.
Conclusion:
ESG appears to detect subclinical sacral function missed by DRE, and these findings may be prognostically meaningful. Patients with ESG-positive/DRE-negative findings demonstrated higher AIS conversion rates and more consistent neurological recovery than matched controls. These pilot data suggest that silent sacral sparing may be more common and clinically relevant than previously recognized. ESG may strengthen early prognostication and support more precise rehabilitation planning after acute SCI.
