The pathogeny and electromyography of myokymia / 中华物理医学与康复杂志

ABSTRACT

Objective To research the pathogeny and the electromyographic characteristics of myokymia.Methods The clinical features and electromyography of 42 elderly patients with myokymia were examined. Results Symptomatic myokymia (SM) in 27 cases was caused by low salt syndrome, thyrotoxemia, urinaemia, chronic wasting diseases (such as carcinoma of the stomach or liver), brachial plexus neuropathy, lead poisoning, chronic inflammatory demyelinating polyradiculoneuritis, succinylcholine narcosis, restless leg syndrome or Isaac's syndrome.Symptomatic facial myokymia was caused by neoplasm of the brain stem or in posterior cranial fossa, multiple sclerosis or other causes. Primary myokymia ( PM ) in 15 cases involved idiopathic generalized and benign myokymia.Compared with PM, SM was more constant and powerful. Myokymia potential appeared in the electromyograms of 42 of the patients. The majority of patients with SM had accompanying myotonic discharge. Conclusion The pathogeny and electromyographic characteristics of symptomatic myokymia are different from the primary stage.