This protocol was developed as an effort to characterize new neuromuscular diseases, to learn more about established diseases, to assess current methodologies and technologies and to refine old methods as well as to develop new ones. Using different electrodiagnostic techniques, we have carried on a number of different studies: a. Power spectrum of surface electromyography (EMG) in myopathy: Surface recording of the muscle, EMG may provide a painless alternative to needle electromyography in neuromuscular diseases. Analysis of surface EMG in patients with biopsy-proven myopathy suggests that ratios of the power at low and high frequencies may increase the sensitivity of the test. b. Autonomic studies in Fabry's disease: A basic battery of autonomic testing that can be done in the EMG laboratory, including sympathetic skin responses, Valsalva ratio and heart rate variability with respiration, has been used to study autonomic function in these patients. Preliminary results have shown some abnormalities, primarily with cardiac parasympathetic function. c. Reproducibility of quantitative sensory studies: We have performed serial quantitative sensory studies in a group of healthy volunteers to define the intertrial and intraindividual variability for the different modalities of testing. This test is being used for the evaluation of peripheral neuropathy.
