[Chronic inflammatory demyelinating polyradiculoneuropathy: clinical heterogeneity and therapeutic perspectives]

Since the first description of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) by PJ Dyck's group at the Mayo Clinic 35 years ago, a wide range of publications have underlined the clinical, electrophysiologic and histopathologic heterogeneity of this disease. Expert consensus opinion is that CIDP should be considered in any patient with progressive symmetrical or asymmetrical polyradiculoneuropathy whose clinical course is relapsing and remitting or progresses for more than two months, especially if there are positive sensory symptoms, proximal weakness, are flexia without wasting, or preferential loss of vibration or joint-position sense. Electrophysiologic features of demyelinating polyneuropathy (especially conduction blocks) and elevated protein levels in cerebrospinal fluid may assist with the diagnosis. However, various clinical pictures have been described in patients with CIDP including pure motor or sensory impairment, and distal, multifocal or focal distribution. Two specific points have recently been emphasized:--while most CIDP patients have chronic onset, acute onset resembling Guillain-Barré syndrome may sometimes occur;--pure sensory forms may require different diagnostic strategies, including the use of somatosensory evoked potentials showing abnormal proximal sensory conduction, and nerve biopsy showing macrophage-associated demyelination, onion bulb formation, demyelinated and partially remyelinated nerve fibres, endoneurial edema, endoneurial mononuclear cell infiltration, and variation between fascicles. Several sets of diagnostic criteria for CIDP have been proposed, with different sensitivities and specificities. The European Federation of Neurological Societies/Peripheral Nerve Society criteria strike a balance between specificity, which needs to be higher for research purposes than for clinical diagnosis, and sensitivity, which, if too low, might lead to some cases being missed. CIDP patients may have a variety of comorbidities, including diabetes mellitus and IgG or IgA monoclonal gammopathy of undetermined significance. Since the first clinical trial of prednisone in CIDP, several randomized trials have given rise to evidence-based therapeutic approaches. Treatment induction with corticosteroids or intravenous immunoglobulin should be considered for patients with disabling sensory and motor CIDP. Plasma exchange is similarly effective but may be less well tolerated. The existence of relative contraindications to these treatments will determine the choice. The advantages and disadvantages of available treatments should be explained to the patient, who should be involved in the decision-making process. If the response is inadequate or if maintenance doses of the initial treatment are poorly tolerated, alternatives include combination therapy or the addition of an immunosuppressant or immunomodulatory agent, but the evidence is too weak to recommend a particular drug.