Idiopathic chronic immune-mediated neuropathies: chronic inflammatory demyelinating polyradiculoneuropathy and multifocal motor neuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a chronic demyelinating neuropathy which is deemed to be caused by an immune attack against peripheral nerve myelin [1–3]. It is a rare neuropathy with a prevalence ranging from 0.8/10,000 in Japan [4] to 8.9/100,000 in Olmstead County, USA [5]. CIDP usually presents with a relatively symmetric chronic relapsing or chronic progressive sensorimotor impairment that evolves over the years and that, if untreated, may lead to a consistent disability. A few different clinical presentations have been reported [3, 6] broadening the spectrum of CIDP. These include multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy also known as LewisSumner syndrome, distal acquired demyelinating symmetric (DADS) neuropathy, pure motor CIDP, pure sensory CIDP including chronic immune sensory polyradiculopathy (CISP) and focal CIDP. These forms are currently considered to be variants of CIDP, even if the presence of some differences in their response to therapy does not permit to exclude that they represent different forms of demyelinating neuropathies.