 To do this, the investigators have available a UHF ultrasound in the ultrasound department of the Nice University Hospital Pasteur Hospital 2 The investigators realize a descriptive analysis study, pilot, mono-centric, multi and prospective on patients followed in the center with a diagnosis of IPDC, a NMMBC or neuropathy with anti-MAG antibodies and control subjects matched by age and sex. All the patients and controls in this study will receive a briefing and must sign an informed consent. 