[Electrophysiologic investigations in a family with malignant hyperthermia (author's transl)].

The value of the quantitative electromyogram in the detection of subclinical myopathic signs was tested in a family consisting of 11 members, one of them showing a Malignant Hyperthermia crisis. Furtheron an in vitro contracture test and an ATP-test was performed and the Serum CPK and the isoenzyme in serum and muscle examined. The following conclusions were taken: 1) Although unspecific pattern (in 5 cases more than 12% polyphasic potentials were found, one of them showing a reduction of the mean duration of 30%) the electromyography is a good but not absolutely certain indicator of subclinical myopathic signs in Malignant Hyperthermia. 2) The exclusion of M.H. risk is not possible using a single test. 3) The diagnostic value of not invasive methods, as the electromyography is of special importance. The diagnostic use of many M.H. tests seems necessary.