Chronic inflammatory demyelinating polyradiculoneuropathy overdiagnosis in Russia

Introduction. Despite the improving diagnostic criteria for the chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), its verification is still an issue. Objective: to study the rate and the causes of CIDP misdiagnosis. Materials and methods. We prospectively and retrospectively analyzed the clinical and paraclinical data of 223 patients admitted to the Research Center of Neurology from 2018 to 2022 with a CIDP referral. Results. We revised the CIDP diagnosis in 150/223 patients (67%; median age 55.5 [43; 63] years; 75 males and 75 females; 3-year follow-up history [1.75; 5.25].) Once the definitive diagnosis was clarified, we divided the patients into the following groups: polyneuropathy of other etiology (n = 94; 63%), other neuromuscular disorders (n = 39; 27%), CNS disorders (n = 10; 7%), no structural NS disease (n = 7; 5%). Patients did not meet the 2021 EAN/PNS diagnostic criteria at the history-taking stage in 65% of cases, at the neurological examination stage in 39% of cases, and at the electroneuromyography stage in 92% of cases. Conclusions. The rate of CIDP misdiagnosis in Russia is 67%, and most often this refers to patients with polyneuropathy of other etiologies. The main cause for the CIDP misdiagnosis was inaccurate electroneuromyography. We should bear in mind that CIDP is a rare disorder with an extensive differential diagnosis, so it should be verified according to the current 2021 EAN/PNS diagnostic criteria.