Spinal Circuit & Epidural Electrical Stimulation (EES) Simulator

1. Pathology & Lesion Architecture

Spinal Lesion Level

Severance Severity

Stem Cell / Neurotrophic Adjunct

Simulates local BDNF/GDNF paracrine secretion, glial scar digestion, and micro-axonal sprouting across the transection cavity.

2. Epidural Paddle Array (EES)

Target Segment Array

Stimulation Frequency 40 Hz

10 Hz (Tonic) 40 Hz (Locomotor CPG) 120 Hz (Tetanic)

Current Amplitude 3.8 mA

0.5 mA (Subthreshold) 3-5 mA (Afferent Entry) 8.0 mA (Root Block)

Patient Context (Source Grounded)

Case Daniel (25y): Severe traumatic C6-C7 spinal injury post-trampoline fall. Tetraplegia chest down; underwent 6 nerve-transfer procedures. Evaluating foreign commercial neuromodulation protocols (Verita Neuro, Thailand; $187,500+).

"Epidural stimulation acts as an excitability amplifier for dormant spinal networks, not a conduit that physically re-wires severed long-distance motor tracts."

Dorsal 1a Afferent Rate 84%

Interneuron Membrane -52 mV

Supraspinal Conduction 0% past C6

ELECTROPHYSIOLOGY (DORSAL ROOT AFFERENTS & ALPHA-MOTONEURON EMG)

Real-time Neurodynamic State

1a Proprioceptive Recruitment

84%

Spinal Interneuron Vm

-52 mV

Descending Drive Past Lesion

CPG Phase Synchrony

0.89

Active Functional Outcome

Coordinated cyclical motor output in quadriceps/gastrocnemius; voluntary initiation requires residual descending sparing.

Clinical Mechanism & Verdict

Primary Biophysical Mechanism: EES recruits posterior root 1a/1b proprioceptive afferents rather than motor axons directly. High-frequency depolarizing volleys elevate lumbosacral or cervical interneuronal networks to a subthreshold state (-52 mV), enabling even faint spared supraspinal volleys (or peripheral reflex inputs) to generate functional muscle contractions.

Stem Cell Realism: Neurotrophic paracrine signaling can modestly foster 100-300 μm axonal sprouting, but long-tract corticospinal regeneration across complete lesions has never been verified in human clinical trials without intensive locomotion task-specific training (>50-100 sessions).

Export & Protocol Summary