Central core disease and malignant hyperthermia syndrome.

In a detailed investigation of a family with musculoskeletal abnormalities observed in four generations, the proband and his mother were found to have central cores and multicores on histochemical and electron microscopic studies of biopsied muscle. A male sibling experienced a malignant hyperthermic reaction during hand surgery, and although similar reactions had not been observed in other family members, unexplained ventricular dysrhythmias did occur in the proband during surgery. The proband and his mother were subsequently shown to be susceptible to malignant hyperthermia by abnormal in vitro muscle contractures in the presence of halothane or caffeine. Physicians and dentists caring for patients with central core disease should be aware of its possible association with malignant hyperthermia. Complete evaluation of patients with central core disease should include in vitro muscle contracture studies for malignant hyperthermia since many of patients require surgery for musculoskeletal defects.