[Congenital neuromyotonia. Retrospective study of 4 cases].
BACKGROUND
Fasciculation, double discharge, myokymia and neuromyotonia are different kinds of involuntary muscular activity that originate in ectopic discharges of the motor axons. Electrophysiological studies are needed in all cases for the diagnosis. Non rigorous electrophysiological studies in some cases is the cause of the historically unclear nosological delimitation of the neuromyotonic syndromes.


OBJECTIVE
To report the clinical picture and electrophysiological findings in patients with congenital neuromyotonia.


METHODS
Four patients with congenital neuromyotonia were studied. Electrophysiological exam included nerve conduction measurements, study of the after-discharges and conventional EMG. Spontaneous discharges were displayed after applying a low pass filter, signal trigger and delay line.


RESULTS
In one case positive motor features predominate (continuous muscle fiber activity). On the contrary, two cases, showed neuropathic deficitary signs with a Charcot-Marie-Tooth type II disease phenotype; neuromyotonia was, in both cases, an electrophysiological feature. In the last patient, motor signs were limited to the facial muscles but electrophysiological study discovered generalized neuromyotonia. Treatment with carbamazepine or oxcarbazepine was useful in the four cases.


CONCLUSIONS
Congenital neuromyotonia is a clinically heterogeneous syndrome with uniform electrophysiological features that permit its qualification.
Montero Homs
J
J
Servicio de Neurología de la CSUB, L'Hospitalet de Llobregat, Barcelona. jmonteroh@meditex.es
Barraquer Bordas
L
L
Martínez Matos
J A
JA
Peres Serra
J
J
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D020386:Isaacs Syndrome / Q000151:congenital* / Q000175:diagnosis / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies