Myotonic dystrophy: limited electromyographic abnormalities in 2 definite cases.
Two women, aged 37 and 38, with definite myotonic dystrophy are presented. Neither patient had clinical myotonia although both experienced intermittent jaw tightness. Electromyographic (EMG) myotonia was seen only in the masseter muscle in one and in the masseter and flexor pollicis longus muscle in the other patient. The detection rate of EMG-myotonia in clinically normal heterozygotes increases if distal, proximal and cranial nerve innervated muscles are examined.
D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D009223:Myotonic Dystrophy / Q000175:diagnosis* / Q000235:genetics; D010375:Pedigree