Longitudinal Quantitative Neuromuscular MRI in Neuropathic Patients

Inclusion Criteria: * Male or female between 18 and 80 years of age, * Patients who have freely given their consent to participate in this study, * Patient with genetically confirmed hereditary CMT neuropathy * or patient with an acquired demyelinating neuropathy such as typical PIDC or anti-MAG of typical form * or a patient with a genetically confirmed pathogenic mutation in the transthyretin (TTRn) gene, * Patients who are beneficiaries or entitled beneficiaries of a social security scheme. Exclusion Criteria: * Patients with co-morbidity or a history of other peripheral neuropathy, * Patients with alcohol or psychoactive substance abuse, * Patients with contraindications to MRI exploration: claustrophobia, pacemakers, Holter systems, IUDs, metal surgical clips, metal prostheses or implants (or other metal foreign bodies), * Patient unable to perform the MRI due to severe handicap, * Patient in a period of exclusion from another research protocol at the time of signing the consent/non-opposition form, * Subjects covered by articles L1121-5 to 1121-8 of the French Public Health Code (minors, adults under guardianship or trusteeship, patients deprived of their liberty, pregnant or breast-feeding women), * Persons who cannot read and understand the French language well enough to be able to give their consent to participate in research.