The ratio of acoustic myography to surface electromyography amplitude significantly differentiated children with muscle disease from normal volunteers (P<0.01), yielding 82% sensitivity and 91% specificity.
Case-Control (n=27)
Does the ratio of acoustic myography to surface electromyography amplitude accurately diagnose pediatric muscle disease?
The ratio of acoustic to surface EMG amplitude provides high sensitivity and specificity for diagnosing pediatric muscle disease.
p-value: p=<0.01
The ratio of acoustic myography (AMG) amplitude to surface electromyography (EMG) amplitude is proposed as a measure of mechanical output compared with electrical activity of the contractile system. AMG to EMG ratios were measured from 16 children with muscle disease diagnosed by clinical criteria, EMG, and/or muscle biopsy. These were compared with the ratios from 11 normal volunteers spanning the same age range (7-16 years). AMG to EMG ratios were significantly (P less than 0.01) different for the two populations. Using a linear discriminant function to define the normal range for AMG to EMG ratios yielded a sensitivity of 82% (13 of 16 abnormals diagnosed) and a specificity of 91% (10 of 11 normals). These findings suggest that surface recordings may provide significant diagnostic information in muscle disease. The accuracy may be improved further by using additional muscles (e.g., paraspinals) and evoked twitches.
Barry et al. (Sun,) conducted a case-control in Pediatric muscle disease (n=27). Acoustic myography (AMG) to surface electromyography (EMG) amplitude ratio vs. Normal volunteers was evaluated on AMG to EMG amplitude ratio (p=<0.01). The ratio of acoustic myography to surface electromyography amplitude significantly differentiated children with muscle disease from normal volunteers (P<0.01), yielding 82% sensitivity and 91% specificity.