Les neuropathies douloureuses à petites fibres, de découverte en découverte…

Small fiber neuropathies (SFN) are related to dysfunctions of small A and/or amyelinic small-myelinated fibers. Clinically, length-dependent SFN and non-length-dependent SFN are distinguished. SFN are said to be mixed if they are associated with an involvement of large-caliber sensory fibers resulting in altered conduction velocities in electro-neuromyography. Otherwise, they are said to be pure. To objectify them, the skin biopsy or the evoked potentials laser are recommended. The investigation of etiologies is guided by interrogation and clinical examination and by exploratory biological tests. Treatment will be etiologic if possible. The treatment of neuropathic pain is imperative, but it is sometimes disappointing especially in drug-resistant forms. The discovery of MFN-associated chanellopathies is expected to disrupt a number of so-called idiopathic MFNs so far. It could also allow significant therapeutic advances in the future.