[When should you consider a muscular disease?]

Muscle diseases can take different clinical aspects and some unusual symptoms are often underestimated. Weakness of proximal limb muscles is the most frequent but distal weakness can be observed. Sometimes oculomotor, bulbar, facial, respiratory, paraspinal muscles or myocardium involvement may be the expression of a muscle disease. Similarly it is important to recognize a muscle disease in occurrence of neonatal hypotonia, muscle hypertrophy, muscle stiffness, transitory paralytic episodes, fatigability, myalgia, rhabdomyolysis or isolated increased creatine-kinases level. Biological and electrophysiological examinations have essentially a role in pointing a muscle disease. Muscle biopsy keeps the key role in the diagnosis. Muscle imaging allows mapping of the lesions and new techniques of NMR spectroscopy constitute an in vivo approach of muscle metabolism.