Dynamic Epidural Monitoring of Spinal Cord Neural Conduction Using a Novel Implantable Electrodiagnostic Sensor: A...

To evaluate the feasibility and diagnostic sensitivity of a novel catheter-based epidural electrodiagnostic (EDX) system for real-time, segment-specific monitoring of spinal somatosensory conduction in a pre-clinical model of acute spinal cord injury (SCI). A custom-designed EDX electrode catheter was epidurally placed over the thoracic spinal cord in anesthetized rats (n = 5) to record compound evoked potentials across five stages: Baseline, Hypoxia, Post-SCI, Post-SCI Hypoxia, and Post-SCI Recovery. Waveform morphology, onset/peak latencies, and amplitudes were extracted. Paired t-tests compared baseline to experimental stages, and analysis of covariance (ANCOVA) assessed injury force effects on conduction metrics. Postmortem recordings confirmed the biological origin of signals. The EDX system consistently recorded high-fidelity biphasic spinal evoked responses. SCI induced significant increases in N-Onset latency across all post-injury stages (Cohen's d = 2.45-3.04), while N-Peak and P-Peak latencies also increased significantly Post-SCI (Cohen's d = 2.03-2.57), reflecting conduction slowing and partial demyelination. ANCOVA revealed that injury force had large effects on N-Onset (η2_p = 0.872) and P-Onset (η2_p = 0.492). After adjustment, group effects remained significant for N-Onset (η2_p = 0.799), P-Onset (η2_p = 0.513), and N-Peak (η2_p = 0.565). Although P-Peak and amplitude changes did not reach significance, their effect sizes (η2_p > 0.06 and >0.01) suggested a clinically meaningful influence. These findings support the EDX system's sensitivity to both the presence and severity of SCI. This proof-of-concept study demonstrates the feasibility and diagnostic value of an epidural EDX platform for real-time segmental monitoring of spinal conduction. The system's robust sensitivity to latency shifts and force-dependent modulation underscores its potential for intraoperative neuromonitoring, SCI diagnosis, and injury stratification. Its dorsal column targeting and catheter-based design also support integration into closed-loop neuromodulatory frameworks and longitudinal neurorehabilitation, providing a foundation for future clinical translation.