LMN denervated muscle: management and monitoring of h-bFES

Lasting complete denervation is the result of lower motor neuron (LMN) or peripheral nerve lesions that have major consequences on the muscle tissue. The human time course from atrophy to degeneration in large mammals lasts longer (in years) than generally accepted. After early atrophy, the midand late-phases presents two very contrasting myofibers populations: beside those severely atrophic with internalized groups of myonuclei, large fast-type muscle fibers continue to be present 4 to 6 years after SCI. A cell-based mechanism, the myoblast proliferation-dependent regenerative process takes place in permanent LMN denervated muscle. Recent results of animal experiments provides the rational basis of the ability of LMN denervated muscle to respond to home-base functional electrical stimulation (h-bFES) using custom-designed electrodes and stimulators developed in Vienna (Austria). Important benefits of the h-bFES induced increase of mass and tetanic contractility of leg muscles are the improved cosmetic appearance of lower extremities, the enhanced cushioning effect for seating and the reduction of leg edema. Further outcomes are a world-unique cirMyo-Bank of muscle biopsies and new imaging procedures (Color CT scan and Functional Echomyography). They demonstrate that h-bFES induces improvements of muscle contractility, mass and tissue composition, despite permanent denervation. Functional Echomyography, an improved ultra sound dynamic imaging, objectively demonstrate the improvements and allow adjust the stimulation protocols to the changing needs of LMN denervated muscles. The benefits of hbFES could be extended to patients with similar lesions (incomplete LMN denervation of skeletal muscles) especially to determine whether this training can reduce secondary complications related to disuse and impaired blood perfusion (reduction in bone density, risk of bone fracture, decubitus ulcers, and pulmonary thromboembolism). We are confident that translation of the results of a clinical experiment, the EU Project RISE, to the larger cohort of incomplete LMN denervated muscles will provide the wanted results.