Quantitative electromyography

Several quantitative electromyography (QEMG) methods are used for diagnosing and monitoring in patients with neuromuscular disorders. At weak effort of the muscle, motor unit potential (MUP) analyses as individual MUP, multi-MUP, and macro-EMG are diagnostically sensitive and well tested. At higher effort of the muscle, interference pattern analyses such as the turns amplitude analysis are also diagnostically sensitive. Other potential diagnostic methods are power spectrum analysis, muscle fibre conduction velocity analysis, and some surface EMG methods. In patients with myopathy, QEMG has an important role in the diagnosis as a supplement to blood tests, muscle biopsy, and genetic testing. In patients with neurogenic disorders such as anterior horn cell disorders, peripheral nerve lesions, or polyneuropathy, QEMG has important roles in characterizing the lesion and differential diagnosis. Furthermore, QEMG may be useful in the examination of patients with neuromuscular transmission failure, critical illness disorders, and in treatment of dystonic muscle with botulinum toxin.