Chronic inflammatory demyelinating polyradiculoneuropathy: can we make a diagnosis in patients not fulfilling electrodiagnostic criteria?

Background and purpose: The aim was to identify the clinical and diagnostic investigations that may help to support a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in patients not fulfilling the European Federation of Neurological Societies and Peripheral Nerve Society(EFNS/PNS) electrodiagnostic criteria.Methods: The data from patients with a clinical diagnosis of CIDP included in a national database were retrospectively reviewed.Results: In all, 535 patients with a diagnosis of CIDP were included. This diagnosis fulfilled the EFNS/PNS criteria in 468 patients (87.2%) (definite in430, probable in 33, possible in three, while two had chronic immune sensorypolyradiculopathy). Sixty-seven patients had a medical history and clinical signs compatible with CIDP but electrodiagnostic studies did not fulfill theEFNS/PNS criteria for CIDP. These patients had similar clinical features and frequency of abnormal supportive criteria for the diagnosis of CIDP compared to patients fulfilling EFNS/PNS criteria. Two or more abnormal supportive criteria were present in 40 (61.2%) patients rising to 54 (80.6%) if a history ofa relapsing course as a possible supportive criterion was also included.Increased cerebrospinal fluid proteins and response to immune therapy most frequently helped in supporting the diagnosis of CIDP. Response to therap