P88-F Electromyographic findings in our cohort of patients with congenital muscular dystrophies and congenital myopathies

Introduction Congenital myopathies (CM) followed by Congenital muscular dystrophies (CMDs) are the most common muscular cause of floppy infant syndrome. It is well known that EMG pattern in both groups is similar, but it is recently described a characteristic association between peripheral neuropathy and some congenital muscular dystrophies. The objective of this presentation is to describe the EMG findings in our cohort. Material and methods We reviewed retrospectively charts and EMG studies of patients with genetically confirmed Cand CM followed in our Hospital in order to evaluate the pattern of EMG involvement. Results All patients showed proximal myopathic changes at EMG. Only one patient with DMC had spontaneous activity at rest (LAMA2). Three patients shared a mixed pattern: First patient with col VI myopathy showed a distal motor axonal neuropathy (similar to distal motoneuron disease), the second one with col VI myopathy displayed minor motor conduction abnormalities but with loss of motor unit at distal muscles and a third patient with LAMA2 Cexhibited isolated sensory motor desmyelinating findings. Conclusions In our cohort only 37% of Cpatients show association of neuropathy and myopathy at EMG. In patients with floppy infant syndrome we suggest to perform nerve conduction studies and needle EMG at proximal and distal muscles to evaluate the association between myopathy and motor neuropathy to achieve a correct electrodiagnosis. It will be interesting to perform longitudinal studies to know if neuropathy is a finding that develops during the follow up and if it depends on the type of genetic abnormality.