Incidence and Natural History of Idiopathic Chronic Inflammatory Demyelinating Polyneuropathy: A Population-Based Study in Iceland

Abstract

Background and Aim: We report a population-based study conducted in Iceland to determine the incidence, clinical characteristics and prognosis of idiopathic chronic inflammatory demyelinating polyneuropathy (CIDP) during a 21-year period. Methods: Cases were identified from the records of all practicing neurologists in the country, the only neurology department in the country and both neurophysiology laboratories. All index cases met the 2010 European Federation of Neurological Societies/Peripheral Nerve Society criteria for CIDP. Results: Nineteen individuals fulfilled the diagnostic criteria during the study period. The average annual incidence was 0.3/100,000 (95% CI 0.04-2.47). There were 14 men (74%) in a gender ratio of 1:2.8. The mean age at diagnosis was 57 (range 19-81 years): women, 36 years and men, 63 years; p = 0.0006. The disease course was remitting-relapsing in 21% and chronic progressive or monophasic in 79%. The average length of follow-up was 6.9 years. The standardized mortality ratio for the 21-year study period was 0.9 (95% CI 0.3-2.2). Conclusion: We believe we have identified all diagnosed with CIDP in Iceland during a 21-year period. Many had no or only limited disease progression over the years and mortality is not increased compared with the general population.

Incidence and Prevalence of Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Systematic Review and Meta-Analysis

“…Only one incidence study used the most recent EFNS/PNS criteria (2010) to confirm the diagnosis of CIDP. In contrast, this study found a lower incidence rate compared to studies using the AAN criteria, which may be explained by the exclusion of the category of patients with a "possible" CIDP in this study [32]. Of one study, we included estimates based on the EFNS/PNS 2006 criteria and excluded estimates based on the AAN criteria in the meta-analysis to avoid overrepresentation of this study in our sample [18].…”

“…After reviewing the full text of the remaining articles, 47 articles did not fulfil the following inclusion criteria: English language (n = 6), full text available (n = 3), reporting prevalence and/or incidence rates (n = 6), fulfilment of general accepted diagnostic criteria for CIDP (n = 3), original data (n = 28) and no duplication (n = 1). We contacted the corresponding authors of 2 studies because of missing data for conducting a meta-analysis; one author provided the required information (crude incidence rate, number of cases and person-years) [32]; one author could not provide the required information [33]. Finally, we included 11 publications for this systematic review of which 9 studies were sufficient for meta-analysis of prevalence [9-13, 18, 34-36] and 5 studies [11,13,18,32,34] for meta-analysis of incidence (Fig.…”

“…The observed incidence and prevalence rates may seem to increase in more recent studies, but no statistical significant trend in time for incidence is found [32,33]. Although the pathogenesis and aetiology of CIDP is far from understood, previous studies reported infections and vaccinations preceding the onset of CIDP symptoms [52][53][54][55][56].…”

“…We included 5 incidence studies in the meta-analysis of incidence [11,13,18,32,34]. In the meta-analysis of incidence, 818 cases and 220,513,514 person-years were included.…”

Chronic inflammatory demyelinating polyneuropathy: update on diagnosis, immunopathogenesis and treatment

“…CIDP is considered an orphan disease with different prevalence rates in different geographical regions (figure 2). [4][5][6][7] In a study from England, Mahdi-Rogers and Hughes 5 reported a prevalence rate of 2.84 per 100 000 for CIDP. In this study male patients outnumbered female patients by 2:1, and CIDP was more prevalent in advanced age.…”