Pseudomyotonia Syndrome of Isaacs Definition
Pseudomyotonia Syndrome of Isaacs: A rare neuromuscular disorder with onset usually in late childhood or early adulthood, characterized by intermittent or continuous widespread involuntary muscle contractions; FASCICULATION; hyporeflexia; MUSCLE CRAMP; MUSCLE WEAKNESS; HYPERHIDROSIS; TACHYCARDIA; and MYOKYMIA. Involvement of pharyngeal or laryngeal muscles may interfere with speech and breathing. The continuous motor activity persists during sleep and general anesthesia (distinguishing this condition from STIFF-PERSON SYNDROME). Familial and acquired (primarily autoimmune) forms have been reported. (From Ann NY Acad Sci 1998 May 13;841:482-496; Adams et al., Principles of Neurology, 6th ed, p1491)
Synonym: acquired neuromyotonia, isaacs syndrome, isaacs pseudomyotonia syndrome, isaacs mertens syndrome, isaac syndrome, gamstorp wohlfart syndrome, continuous myokymia, continuous muscle activity syndrome, syndrome of continuous muscle activity, quantal squander, pseudomyotonia, neuromyotonia, isaacs-mertens syndromes, gamstorp-wohlfart syndromes.
Additional tags: pseudomyotonia