1-A-D-12. Utility of quantitative and non-invasive surface EMG analysis for pediatric neuromuscular disorders

Abstract

Needle electromyography is invaluable for diagnosis of pediatric neuromuscular disorders, although the procedure is too painful. In this study, we tested the utility of the Clustering Index (CI) method, a quantitative analysis for surface electromyography (SEMG), for the differential diagnosis of pediatric neuromuscular disorders. Subjects were 39 children with neuromuscular disorders (15 neurogenic and 24 myopathic patients). Their age averaged 8.8 ± 4.1 years. SEMG was recorded at the tibialis anterior muscle. Ankle dorsiflexion was achieved by instruction or by tickling the sole. The SEMG signal of one-second length with stable intensity was used as an epoch for further analyses. In total, 836 epochs from neurogenic patients and 992 epochs from myopathic patients were analyzed. CI and area for each epoch were calculated using a 10 ms window width, and the mean discriminant function was calculated for each subject. Using appropriate cut-off values, 7 from 15 neurogenic and 14 from 24 myopathic patients were correctly diagnosed as neurogenic or myopathic with 100% specificity. Especially, 4 of 7 spinal muscular atrophy patients and 9 of 12 Duchenne muscular dystrophy patients were correctly classified. The CI method is a non-invasive and promising tool for differential diagnosis between neurogenic and myopathic conditions in children.