Botulinum Toxin Induced Muscle Denervation: A MRI Study
Several serious genetic diseases, nerve crush injuries, and other long-lasting denervations cause muscle atrophy. Previous magnetic resonance (MR) imaging and spectroscopy studies of the spinal muscle atrophy (SMA) and Duchenne muscular dystrophy (DMD) showed patterns of muscle degeneration, which were typical of each type of the disease.1,2 The aim of our study was to explore animal models of muscle atrophy, which would best correspond to human neurodegenerative diseases. A model of persistent neuromuscular block has been developed by use of the botulinum neurotoxin type A (BoNTxA). Consequent muscular atrophy, followed by regeneration of the affected muscle, was assessed by use of a small MR imaging system, which enables MR imaging and spectroscopy of experimental animals. The importance of presence of the neuromuscular junction, though not secreting Acetylcholine, for the physiological and morphological state of the treated muscle was studied by comparison to other disorders of the neuromuscular junction. Thus, nerve crush injury induced denervation was chosen as a parallel model disease. Investigation of BoNTx induced denervation also seemed to be relevant because of the clinical use of C. botulinum toxins3 — especially with the respect to the duration of denervation and possible side effects.4
KeywordsDuchenne Muscular Dystrophy Muscle Atrophy Neuromuscular Junction Spinal Muscular Atrophy Duchenne Muscular Dystrophy
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