PEAK-RATIO INTERFERENCE PATTERN-ANALYSIS IN THE DETECTION OF NEUROMUSCULAR DISORDERS

Peak-ratio interference pattern analysis (peak-ratio method) is said t o have a high sensitivity and to be independent of sex and age. This s tudy was carried out to prove or disprove these findings. The peak-rat io method and qualitative motor unit action potential (MUAP) analysis were applied to the right brachial biceps and anterior tibial muscles of 44 healthy subjects, aged 23-87 years, 25 neuropathy patients, aged 21-83 years, and 29 myopathy patients, aged 19-70 years. Peak-ratio p arameters were independent of sex and age. They tended to be lower in the anterior tibial muscle than in the brachial biceps muscle. Neuropa thy patients typically showed decreased peak-ratio, short time interva ls and increased amplitude/turn. Myopathy patients typically showed in creased peak-ratio, turns/s and shea time intervals. The sensitivity o f the peak-ratio method was 72% for neuropathy patients and 59% for my opathy patients. The sensitivity of the peak-ratio method was similar to that of the MUAP analysis in neuropathy patients and higher than th at of the MUAP analysis in myopathy patients. The specificity of the p eak-ratio method was 80%. The peak-ratio method proved to be a valuabl e, supplementary electromyographic tool for the detection of neuromusc ular disorders. (C) 1997 Elsevier Science Ireland Ltd.