 They realize an ultrasound study of the nerve, using an ultra high frequency ultrasound system that will allow the assessment of anatomical structures of nerve size, structure, vascularisation and assessment booklets. Ultrasound data will, in a second stage, compared with the data obtained with the EMG and clinical scores obtained using clinical rating scales. 40 subjects will be included, divided into four subgroups: 10 subjects with a diagnosis of IPDC 1, 10 subjects with a diagnosis of NMMBC 2, 10 subjects with a diagnosis of neuropathy antibody-anti MAG 3 and 10 control subjects with no signs of neuropathy at the EMG examination. 