Diagnostic yield of noninvasive high spatial resolution electromyography in neuromuscular diseases

High Spatial Resolution electromyography (HSR‐EMG), a new kind of noninvasive surface EMG based on a spatial filtering technique, was evaluated with respect to the diagnosis of neuromuscular diseases. HSR‐EMG measurements were recorded from 61 healthy subjects and 72 patients with different neuromuscular diseases and analyzed quantitatively. The results indicate that a few parameters such as muscular conduction velocity, dwell time over root mean square, autocorrelation function, and chi‐value are sufficient to recognize and classify specific signal alterations due to neuromuscular disorders. A diagnostic evaluation procedure calculating automatically the most probable diagnosis from the parameter results could assign the correct diagnosis to about 81% of the investigated patients and healthy subjects. Myopathic disorders were recognized with a sensitivity of 85% (specificity: 97%), neuropathic disorders with a sensitivity of 68% (specificity: 98%). We conclude that HSR‐EMG shows a diagnostic validity similar to that described in literature for needle EMG. Moreover, the noninvasive technique provides the advantage of a simple and painless application. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20: 1360–1370, 1997