Paranodopathie à anticorps anti-neurofascine 155 : atteinte conjointe du système nerveux central et périphérique. À propos d'un cas et revue de la littérature

Paranodopathies are characterized by the dysfunction of the paranodal regions (adjacent to the nodes of Ranvier) of the myelinated fibers. They may affect the central and/or peripheral nervous system. Anti-neurofascin (NF) 155 paranodopathy typically causes a distal motor and ataxic chronic inflammatory demyelinating polyreunopathy, sometimes associated with postural tremor. Evidence of central impairment has also been reported. The diagnosis is supported by markedly elevated protein level in the cerebrospinal fluid, severe demyelinating involvement at electroneuromyography, possible abnormalities on cerebral and spinal MRI and especially by the presence of circulating IgG4 subtype anti-NF 155 antibodies. Intravenous immunoglobulins and plasma exchanges may be transiently effective. In case of resistance, improvement has been described with rituximab. We report the case of a 52-year-old man with chronic inflammatory demyelating polyradiculoneuropathy secondarily associated with pseudo-bulbar dysarthria and a dysexecutive syndrome related to anti-NF155 antibody-positive paranodopathy, and describe the main characteristics of this entity.