Muscle diseases in an internal medicine department

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Research Abstract from Rev Med Interne. Jun 2004;25(6):429-434.

Muscle diseases in an internal medicine department

Chauvet E, Sailler L, Madaule S, Astudillo L, Delisle MB, Arne-Bes MC,

Megnin Y, Arlet P.

Service de medecine interne, place Baylac, pavillon des medecines, CHU

Purpan, TSA 40031, 31059 Toulouse cedex 9, France.

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 (n = 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 diagnostic procedure should be evaluated to diminish

the number of non-contributory biopsies.