D5 Electromyography (EMG) and nerve conduction velocity

Title

Electromyography and nerve conduction studies directly evaluate the functional integrity of the peripheral nervous system and the neuromuscular junction, extending to the diagnostic field the models of axonal propagation of E3 and loss of motor units of A10. The compound muscle action potential (CMAP) results from the synchronous sum of the action potentials of individual motor units, and its amplitude is proportional to the number of functional motor axons, while the nerve conduction velocity is calculated directly from the difference in latencies between two points of stimulation, immediate clinical application of the propagation velocity defined in E3. The F wave evaluates proximal conduction to the spinal cord, and the amplitude drop between distal and proximal stimulation quantifies the degree of conduction block (along the same lines as the A4 block criterion). In the needle EMG, the pattern of motor unit recruitment and the presence of pathological spontaneous activity (fibrillations) directly inform the degree of denervation, linking with the ALS model (A10).

ID:4301