Turn/amplitude-analysis in subclinical myogenic lesions.
OBJECTIVE
To investigate the accuracy of the turn/amplitude-analysis (TAA) in the detection of subclinical myogenic lesions, for which Duchenne (DMD) carriers were taken as a model.


METHODS
Conventional EMG (MUAP analysis) and the TAA with/without force monitoring were applied to the right brachial biceps and femoral rectus muscles of 26 healthy subjects, 11 possible DMD carriers and 5 obligate DMD carriers.


RESULTS
Conventional EMG was unspecifically abnormal in 4 possible and 2 obligate DMD carriers, neurogenic in 1 possible DMD carrier and myogenic in none of the DMD carriers. Mean turns/s (T/S), amplitude/turn (A/T) and the ratio (T/S:A/T) were not significantly different between controls and possible or between controls and obligate DMD carriers. With force monitoring, the ratio (T/S:A/T) was myogenic in 1 obligate DMD carrier at 20% of maximum (brachial biceps). One possible DMD carrier showed a neurogenic distribution of the single T/S-A/T pairs around the normal cloud at 60% of maximum (brachial biceps). Without force monitoring, the TAA was normal in all DMD carriers.


CONCLUSIONS
TAA is of limited help in demonstrating subclinical myopathy, irrespective of whether it is carried out with or without force monitoring.
Finsterer
J
J
Ludwig Boltzmann Institute for research in epilepsy and neuromuscular disorders.
Mamoli
B
B
D000328:Adult; D002353:Carrier State; D004576:Electromyography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009136:Muscular Dystrophies / Q000503:physiopathology*