Abstract

Background: Clinical and electromyographical findings of chronic inflammatory demyelinating polyradiculopathy (CIDP) are occasionally observed in patients with multiple sclerosis (MS).

Objective: To define a new inflammatory demyelinating disease unlike MS or CIDP.

Results: We report five patients with a demyelinating disease affecting the central nervous system (CNS) and the peripheral nervous system (PNS). Each case presented a relapsing-remitting course in which CNS involvement preceded PNS involvement All patients fulfilled Barkhof’s criteria on MRI and the McDonald criteria for MS. Two patients had grey matter lesions with typical white matter changes. No systemic inflammatory disease and no metabolic or inflammatory factor for peripheral neuropathy were found. In all cases electromyography showed a demyelinating peripheral neuropathy without conduction block. Four patients fulfilled the European Federation of Neurological Societies / PNS guideline for chronic demyelinating inflammatory polyradiculopathy and Nicolas et al’s criteria for CIDP, one of whom also fulfilled the Ad Hoc Subcommittee criteria for CIDP. Nerve biopsy, performed in two patients, showed histological evidence of CIDP. An improvement of clinical status and neurophysiological parameters was observed in three patients after treatment with either intravenous immunoglobulin (n = 1) or cyclophosphamide (n = 2).

Conclusion: The CNS and PNS demyelination, the absence of oligoclonal bands, and the peripheral demyelination without conduction block indicate pathogenic mechanisms different from MS and CIDP. The chronology of events suggests an entity unlike that involved in acute demyelinating encephalomyelitis. Immunological reactivity against antigens common to peripheral and central myelin may explain why the demyelinating disease affected both the CNS and the PNS.