ABSTRACT
We report an undiagnosed case of myotonia congenita in a 24-year-old previously healthy primigravida, who developed life threatening masseter spasm following a standard dose of intravenous suxamethonium for induction of anaesthesia. Neither the patient nor the anaesthetist was aware of the diagnosis before this potentially lethal complication occurred.
Subject(s)
Anesthesia, General/methods , Myotonia Congenita/chemically induced , Neuromuscular Depolarizing Agents/adverse effects , Pregnancy Complications/chemically induced , Succinylcholine/adverse effects , Trismus/chemically induced , Cesarean Section , Female , Humans , Myotonia Congenita/diagnosis , Neuromuscular Depolarizing Agents/administration & dosage , Pregnancy , Pregnancy Complications/diagnosis , Succinylcholine/administration & dosage , Trismus/diagnosis , Young AdultABSTRACT
Electron spin resonance experiments have been performed on erythrocyte membranes from rats with myotonia induced by treatment with 20,25-diazacholesterol. The results suggest that erythrocyte membranes in this animal model of human congenital myotonia possess a highly significantly increased surface membrane fluidity compared to that of controls. Alterations in the physical state of membrane proteins were not apparent. These findings, also present in human congenital myotonia [Butterfield, Chesnut, Roses & Appel, 1976, Nature (London) 263:159; Butterfield, 1977 (Submitted for publication)], strengthen the concepts that increased membrane fluidity is associated with the presence of myotonia and that congenital myotonia may be a diffuse membrane disease.
