Development and Validation of the ElectroSacroGram (ESG): A Digital Point-of-Care Tool for Real- time Neuro-Sacral Assessment After Spinal Cord Injury

Background Accurate assessment of neuro-sacral function after spinal cord injury or lesion (SCI/L) is critical for diagnosis, prognosis, and early management. However, current bedside methods such as the digital rectal examination (DRE) remain subjective, invasive, and examiner-dependent. Surface electromyography (s-EMG) offers a quantitative alternative but lacks point-of-care integration. We developed and validated the ElectroSacroGram (ESG), a digital, surface-EMG-based tool for real-time sacral neurophysiological assessment. Methods This study aimed to 1) develop the ESG protocol based on clinical consensus; and 2) evaluate its diagnostic performance compared to radiological findings and expert-performed DRE. In this prospective diagnostic accuracy study at a specialized Level 1 trauma center, 52 adult patients with suspected SCI/L and 21 healthy participants underwent ESG and DRE assessments. ESG captured sacral motor (resting anal tone, maximal voluntary anal contraction (maxVAC), reflex (bulbospongious or bulbocavernosus reflex [BSR]), and sensory (electrical perceptual threshold [EPT]) function using s-EMG and electrical stimulation. Clinically relevant DRE parameters were selected by a nine-member expert panel. Content validity was quantified using item and scale content validity indices (I/S-CVI). Although DRE is inherently subjective, it is the current bedside reference standard; therefore, agreement with ESG was evaluated using Cohen’s kappa (k) to assess concurrent validity. Diagnostic accuracy was assessed using contingency tables with imaging-confirmed spinal lesions as reference. Results Normative ESG values were defined in healthy participants. Neurologically impaired patients had lower maxVAC and BSR amplitudes and higher EPT. ESG showed excellent content validity (S-CVI = 1) versus DRE (S-CVI = 0.43). Agreement with DRE was almost perfect for VAC (κ = 0.876) and EPT (κ = 0.881), moderate for BSR (κ = 0.671), and slight for resting anal tone (κ = 0.205). ESG showed 83.3% sensitivity, 100% specificity, and 86.5% overall accuracy for detecting radiological abnormalities. Conclusions ESG is a novel digital diagnostic tool that enables objective, real-time neuro-sacral assessment at bedside. By overcoming the limitations of DRE, ESG may improve diagnostic precision and early decision-making in SCI/L. Its point-of-care digital format supports future integration with clinical decision support systems, remote monitoring platforms, and machine learning models for predictive neurodiagnostic. Multicenter validation and longitudinal modeling are warranted.