Diagnosis and treatment of chronic inflammatory demyelinating polyneuropathy.

Abstract

Chronic inflammatory demyelinating neuropathy (CIDP) is generally considered to be an immune-mediated neuropathy with potential target antigens, although its precise pathogenesis is unclear. Unlike its more acute counterpart, acute inflammatory demyelinating neuropathy, the diagnosis is necessarily delayed as a result of clinical definitions but also the fluctuating clinical manifestations which can evolve over months and years. In addition, as a result of its relative rarity it is not usually definitively diagnosed and treated until patients come into contact with specialist neurology services. However, even within specialist settings the diagnosis is often elusive as a result of heterogeneous clinical manifestations, the patchy nature of the demyelinating pathology and limitations of available diagnostic tests. Despite the limited understanding of disease aetiology, recent studies have underlined the important role of both cellular and humoral components of the immune system in pathogenesis which in turn has informed treatment approaches. Although there remains no overall consensus on the optimum management strategy for CIDP, it is becoming clear that individualising therapeutic interventions depending on accurate identification of the CIDP variant is important. These include the typical symmetrical motor and sensory polyneuropathy, multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), pure motor, pure sensory and distal acquired demyelinating symmetric (DADs) neuropathy, all of which may demonstrate variation in response to intravenous immunoglobulins, plasma exchange (PE) and other immunosuppressive therapies possibly as a result of different underlying pathological mechanisms. In this month’s Journal Club, we review three papers focusing on different aspects of diagnosis and treatment in CIDP. The first paper explores patterns of magnetic resonance neurography and the distribution of nerve hypertrophy in CIDP variants. The second paper reviews different electrophysiological profiles and treatment response in typical and atypical forms, whilst the third investigates predictors of intravenous immunoglobulin (IVIG) responsiveness in patients with CIDP.