Acquired neuromyotonia in childhood: case report and review.
Recently characterized as an immune-mediated channelopaty, Isaacs' syndrome (also known as acquired neuromyotonia) was first described in 1961 in two men with persistent, generalized muscle stiffness, in addition to spontaneous, rapid discharges of motor-unit potentials on electromyography. In the peripheral nervous system, antibodies targeted to voltage-gated potassium channels induce hyperexcitability of motor axons, resulting in signs of muscle stiffness or of pseudomyotonia. A spontaneous burst of single motor-unit activity, and myokymic and neuromyotonic discharges, are the most characteristic features found in electromyography studies. This report describes Isaacs' syndrome in a child, in whom the diagnosis was made by clinical features of acquired, spontaneous muscle overactivity and typical electromyographic findings.
Department of Pediatric Neurology, Pereira Rossell Children's Hospital, Montevideo, Uruguay. viciogon@hotmail.com
Gabriel
G
Gonzalez
Graciela
G
Barros
María Eugenia
ME
Russi
Ana
A
Nuñez
Cristina
C
Scavone
D000293:Adolescent; D000367:Age Factors; D000927:Anticonvulsants / Q000627:therapeutic use; D001323:Autoantibodies / Q000276:immunology*; D002220:Carbamazepine / Q000031:analogs & derivatives / Q000627:therapeutic use; D003937:Diagnosis, Differential; D004576:Electromyography; D006801:Humans; D020386:Isaacs Syndrome / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology*; D008297:Male; D016472:Motor Neuron Disease / Q000276:immunology / Q000503:physiopathology; D009046:Motor Neurons / Q000276:immunology; D018482:Muscle, Skeletal / Q000276:immunology / Q000294:innervation / Q000503:physiopathology*; D009431:Neural Conduction / Q000276:immunology; D009469:Neuromuscular Junction / Q000276:immunology / Q000503:physiopathology; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology*; D013035:Spasm / Q000209:etiology* / Q000503:physiopathology; D016896:Treatment Outcome
D000927:Anticonvulsants; D001323:Autoantibodies; D024642:Potassium Channels, Voltage-Gated; C476610:oxcarbamazepine; D002220:Carbamazepine