Correlating phenotype and genotype in the periodic paralyses.

Background: Periodic paralyses and paramyotonia congenita are rare disorders causing disabling weakness and myotonia. Mutations in sodium, calcium, and potassium channels have been recognized as causing disease.

Objective: To analyze the clinical phenotype of patients with and without discernible genotype and to identify other mutations in ion channel genes associated with disease.

Abdominal wall muscle activity in irritable bowel syndrome with bloating.

Objective: Recurrent episodes of bloating and visible abdominal distension are common and distressing in irritable bowel syndrome, but the mechanisms are unknown. Patients often note that the distension is most pronounced in the upright posture, suggesting that the bloating may be the result of a decrease or absence of the normal rise in electromyograph activity in the abdominal wall muscles when standing. There are no reports of noninvasive electromyograph recordings of abdominal wall muscles in irritable bowel syndrome.

Utility of an EMG mapping study in treating cervical dystonia.

Intramuscular injections of botulinum toxin are the cornerstone of treatment for cervical dystonia. Controversy exists regarding the necessity for EMG-guided injections. We compared the clinical examination of four movement disorder specialists to an electromyographic (EMG) mapping study.

Randomized trials of dichlorphenamide in the periodic paralyses. Working Group on Periodic Paralysis.

Although the carbonic anhydrase inhibitors have been used in the treatment of the primary periodic paralyses (PPs), their efficacy has not been demonstrated in double-blind, placebo-controlled trials. Therefore, we tested the efficacy of dichlorphenamide (DCP; Daranide), a potent carbonic anhydrase inhibitor, in the treatment of episodic weakness in the primary PPs. We performed two multicenter, randomized, double-blind, placebo-controlled crossover trials, one involving 42 subjects with hypokalemic periodic paralysis (HypoPP) and the other involving 31 subjects with potassium-sensitive periodic paralysis (PSPP).