[Definition of a diagnostic score of malignant hyperthermia using P-31 magnetic resonance spectroscopy].

OBJECTIVES

To assess the metabolic muscular disorders associated with malignant hyperthermia (MH) using 31-P MRS, in order to develop a diagnostic tool for MH.

STUDY

DESIGN

Retrospective analysis of a series of case.

PATIENTS: Group of 39 subjects, including 13 MH susceptible (MHS), and 26 not susceptible (MHN) members of recognized MHS families, according to the results of the in vitro contracture tests.

METHODS

Each subject underwent two protocols, both including rest, exercise and recovery periods. Exercise was performed successively under aerobic and ischaemic conditions.

RESULTS AND DISCUSSION: A significant early acidosis was recorded for the MHS group under both conditions of exercise (normoxia and ischaemia). However, the sensitivity of this parameter (77%) was not high enough to be considered as discriminant. Therefore a MRS score has been defined, corresponding to the sum of metabolic anomalies (acidosis, anomalies in PCr tum-over and in ATP or phosphomonoesters concentrations) recorded throughout both protocols. This score provided satisfactory results for both sensitivity (93%) and specificity (93%).

CONCLUSION

31-P MRS can act as a reliable diagnostic tool for MH.