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.