Muscle diseases in an internal medicine department

Purpose. - (1) To describe the causes of muscular symptoms in patients undergoing a muscle biopsy in an internal medicine department; (2) to evaluate the diagnostic value of electromyography (EMG), CPK level and muscle biopsy. Methods. -A retrospective study including 90 patients from June 1995 to March 2001. Results. - The diagnosis were: inflammatory diseases (n = 35), non-organic (n = 24), peripheral neuropathy (12 = 8), undetermined organic diseases (n = 7), metabolic diseases (n = 5), toxic diseases (n = 4), infectious diseases (n = 4), amyloidosis (n = 3). Diagnosis value of EMG, CPK and biopsy for organicity were: sensibility: 82%, 47% and 29%; specificity: 46%, 91%, 100%; positive predictive value: 78%, 94% and 100%; negative predictive value: 50%, 40% and 36%. Muscle biopsy is always normal when CPK and EMG are normal. It allows a diagnosis in one out of three cases if EMG and CPK are differing. It is also indicated when CPK are normal and EMG is myogenic. Conclusion. - Numerous diseases account for muscular symptoms. The low rate of diagnostic muscle biopsy imposes a comprehensive clinical approach of the patient and justify the implication of internal medicine physicians in his care. Early intervention of a psychosomatic medicine practitioner in the diagnosis procedure should be evaluated to diminish the number of non-contributory biopsies. (C) 2004 Elsevier SAS. Tons droits reserves.