Single fiber EMG in a congenital myasthenic syndrome associated with facial malformations.
Six patients with a newly described genetic syndrome in Iraqi and Iranian Jews of congenital myasthenia associated with facial malformations were studied with voluntary and stimulation single fiber EMG (SFEMG). Voluntary SFEMG revealed abnormal jitter in all patients in both extensor digitorum communis (EDC) and orbicularis oculi (OOC) muscles, though much smaller in the clinically unaffected EDC. SFEMG study of OOC muscle by axonal stimulation at rates from 1 to 48 Hz showed the most increased jitter at the highest stimulation frequencies in the majority of end-plates, one-third of which showed maximal jitter at intermediate rates. These results may suggest a postsynaptic abnormality as the underlying cause for the neuromuscular transmission defect, and demonstrate the usefulness of SFEMG in the diagnosis of congenital myasthenia.
Sadeh
M
M
Department of Neurology, Chaim Sheba Medical Center, Tel Hashomer, Israel.
Blatt
I
I
Goldhammer
Y
Y
D000293:Adolescent; D000328:Adult; D004576:Electromyography / Q000379:methods; D005145:Face / Q000002:abnormalities*; D005152:Facial Muscles / Q000294:innervation* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007492:Iran; D007493:Iraq; D007585:Jews; D008297:Male; D008875:Middle Aged; D009468:Neuromuscular Diseases / Q000151:congenital / Q000208:ethnology / Q000503:physiopathology*; D013577:Syndrome