8. Electrical stimulation in denervated muscles 23-24.pdf

ELECTRICAL STIMULATION IN DENERVATED MUSCLES Electrophysical Agents Degree of Physiotherapy San Pablo-CEU University 2023-2024 OUTLINE • DEGRESS OF NERVE INJURY • REINNERVATION PROCESSES • STEPS TO FOLLOW • APPLICATION CONDITIONS 2 MUSCLE ELECTRICAL STIMULATION (MES) • SUBJECTS WITH DENERVATI...

ELECTRICAL STIMULATION IN DENERVATED MUSCLES Electrophysical Agents Degree of Physiotherapy San Pablo-CEU University 2023-2024 OUTLINE • DEGRESS OF NERVE INJURY • REINNERVATION PROCESSES • STEPS TO FOLLOW • APPLICATION CONDITIONS 2 MUSCLE ELECTRICAL STIMULATION (MES) • SUBJECTS WITH DENERVATION: – Maintenance of muscular trophism.. – Treatment using results of strength-duration curves. • SUBJECTS WITHOUT DENERVATION: – Technical resources available. – Patient situation and proposed targets. – MES Intensity. – Patient sensitivity (electrical current). 3 DEGREES OF NERVE INJURY • NEUROAPRAXY • AXONOTMESIS • NEUROTMESIS 4 PERIPHERAL NERVE INJURY (SEDDON, 1954) • NEUROPRAXY: • Lowest degree of nerve injury. • The nerve remains intact but its signaling ability is damaged. • Temporary loss of motor and sensory function (blockage of nerve conduction). • Muscle weakness. • Compression, contusion, edema. • • Lasting an average of 6-8 weeks. Ulnar, median, radial, brachial plexus, sciatic and peroneal nerves. 5 PERIPHERAL NERVE INJURY (SEDDON, 1954) • AXONOTMESIS: •The axon is damaged but the surrounded connective tissue remains intact. •Partial rupture (affecting the axon) but not the nerve trunk): Wallerian degeneration (distal part of the axon) •The rate of outgrowth regenerating nerve fibers about 1 mm to 2 mm per day, of is 6 PERIPHERAL NERVE INJURY (SEDDON, 1954) • NEUROTMESIS: • Most serius nerve injury • Both the axon and connective tissue are damaged. • While partial recovery may occur, complete recovery is impossible. • Needs surgery. 7 REINNERVATION PROCESSES • WALLERIAN REGENERATION – Cleaning process of the neuron. • COLATERAL REINNERVATION: – Non-damaged neurons increase its influencing field including denervated fibers. 8 REINNERVATION PROCESSES • WALLERIAN REGENERATION – Cleaning process of the neuron. – Regeneration follows degeneration: Schwann cells and macrophages remove debris. 9 REINNERVATION PROCESSES • COLATERAL REINNERVATION – Restablishment of neural control of a formerly paralyzed muscle by means of proximal to distal regrowth of nerve fibers, or by sprouting from nearby intact nerve fibers (collateral sprouting). 10 DENERVATED MUSCLE ELECTRICAL STIMULATION • AIM: La trophicité pourrait être définie par l'aspect, le développement,la croissance d'une cellule,d'un organe ,et surtout pour nous: d'un muscle . Donc une bonne trophicité musculaire est importante – To maintain trophism muscle integrity while waiting for the physiologic reinnervation. – To avoid muscle fibrosis due to lack of use to allow reinnervation. 11 STEPS TO FOLLOW • PREMISES: – Rectangular pulses are more efficient than triangular pulses for electrical stimulation. – Neccesary to know if burst of pulses can be used or not. – Pulse duration will be adapted considering the S-D curves values. THERE IS NO SPECIFIC CURRENT – Problems: • Loss of response. • Derivation to adjacent muscles. 12 STEPS TO FOLLOW • 1º. Bursts of rectangular pulses with pulse duration equal to the chronaxie. – Similar to normal conditions. • 2º. Isolated rectangular pulses with pulse duration equal to the chronaxie. – Isolated with interval pulses of 4-6 seconds. – If chronaxie is higher than 30 ms, if not it is better to use the MUT. • 3º. Isolated rectangular pulses with pulse duration equal to the MUT. • 4º. Isolated triangular pulses with pulse duration equal to the deflexion angle. 13 APPLICATION CONDITIONS • Daily treatment. • No more than 10 pulses per muscle and day (use 5 at the beginning) • Bipolar application over denervated muscle. • Treat all the affected muscles. • Rectangular pulses application produces response of inervated and denervated fibers in the same muscle; using triangular pulses there is only response of denervated fibers. • Avoid the use of high intensity that may produce skin burns. • Burn risk using adhesive electrodes!!!! 14 CONCLUSIONS • MES will be different in denervated or healthy muscles. • In denervated muscles the current used will be chosen considering S-D curves results. 15 REFERENCES • Bélanger AY. Evidence-Based Guide to Therapetic Physical Agents. Elsevier Churchill Livingstone 2.002. • Bélanger AY. Therapeutic Electrophysical Agents. Evidence Behind Practice. Lippincott Willians & Wilkins, 2014. • Watson T. Electrotherapy: Evidence-Based Practice. Elsevier, Churchill Livinstone, 2008. • www.electrotherapy.org • Albornoz M, Maya J, Toledo JM. Electroterapia práctica. Barcelona: Elsevier; 2023. • Albornoz M, Maya J. Electroestimulación transcutánea, neuromuscular y neuromodulación. Madrid: Elsevier 2020. 16