[Muscular disorders: unusual or focal presentations]

Despite major development of complementary investigations, diagnosis of muscular disorders is mainly clinical. Myopathies can present with unusual or atypical clinical features: myotonia, periodic paralysis, respiratory failure, swallowing difficulties, ptosis, ophtalmoplegia, camptocormia, distal or asymmetrical limb muscle weakness. It can be cause of inaccurate diagnosis. The clinical variability of muscular disorders must be recognized by physicians to drive diagnosis process and to offer an opportunity for early interventional management strategies. This paper reviews the main atypical clinical features of myopathies and their causes.