Muscle fiber conduction velocity in situ (MFCV) in denervation, reinnervation and disuse atrophy

Objectives - Muscle fiber conduction velocity (MFCV) was performed in disus e atrophy, in denervated muscle and during reinnervation as a possible inde x of muscle atrophy, and to clarify the evolution of the fiber size. Materi al and methods - MFCV was performed in 12 patients with complete denervatio n of biceps brachii muscle and during various stages of reinnervation. Twen ty-one patients with disuse quadriceps atrophy were also tested. invasive M FCV was performed according to the method reported elsewhere (2). Results - MFCV decreased significantly in denervated muscles. Reduction of MFCV was found during the first weeks and was progressive. Peak frequency in histogr ams decreased and the normal Gaussian distribution was lost. MFCV increased progressively after reinnervation with coexistence of slow and significant increase of faster MFCV. MFCV decreased significantly also during the firs t weeks after immobilization and improved by rehabilitation therapy. Conclu sion - MFCV is a reliable method to test the muscle fiber size after denerv ation and immobilization, and its evolution by reinnervation and therapy.