Diagnosis of atypical forms of chronic inflammatory demyelinating polyradiculoneuropathy: a practical overview based...

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare disease and the diagnosis is complicated by heterogeneity of the variant forms. Underdiagnosis is undesirable as effective treatments exist. Conversely, overdiagnosis can lead to inappropriate and expensive treatment and delay the initiation of appropriate treatment.

The European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria are used widely in clinical trials and clinical practice. A limitation of the criteria is the requirement for at least one demyelinating parameter as there are certain situations (e.g. proximally located demyelinating process, secondary axonal loss, predominant involvement of sensory fibers) where this criterion may be not apparent; this can lead to misclassification of the neuropathy as axonal. To prevent this situation, the French CIDP Study Group has proposed a set of clinical and electrophysiological signs that are atypical for chronic idiopathic axonal polyneuropathy and suggestive for CIDP. Greater use of supportive diagnostic tools such as magnetic resonance imaging in clinical practice is not only extending the boundaries of CIDP but also contributing to over-representation of some variants, such as those involving the plexus, and sensory or minimal forms of CIDP. Many misdiagnoses can be avoided by adapting the diagnostic strategy to the clinical phenotype of CIDP.

Early and accurate diagnosis of CIDP facilitates the selection of appropriate therapy to improve prognosis. Understanding the limitations of diagnostic criteria and adapting the diagnostic strategy to clinical phenotype can enhance precision and avoid diagnostic pitfalls.