Epidemiology of Neuralgic Amyotrophy—A Retrospective Analysis of Data From a Large German Health Insurance Company

Introduction/Aims Neuralgic amyotrophy (NA, Parsonage–Turner syndrome) is a common, multifocal, autoimmune inflammatory disease that predominantly affects proximal nerve segments of the shoulder girdle. Despite the high incidence of 100/100,000, epidemiologic data based on larger cohorts are still lacking. This study aims to address this issue. Methods A retrospective evaluation of billing data from an average of approximately 26,000,000 insured persons of a large German health insurance company was performed from 2013 to 2022. In addition to descriptive statistical methods, regression analyses were carried out. Results The incidence and prevalence of NA were 7.7–12.8 and 19.7–21.6 per 100,000 people, respectively. During the study period, a steady decline in incidence and, to a lesser extent, prevalence was observed. The diagnosis was made significantly more frequently in the first quarter of the year than in any other quarter. The prevalence of a simultaneously coded diaphragmatic paresis (indicating the involvement of the phrenic nerve) was 0.45%. Discussion Compared with prospectively collected data, the data in this study revealed an approximately 90% lower incidence of NA. It is likely that the majority of cases are not correctly diagnosed and are therefore not captured in the billing data. The involvement of the phrenic nerve in patients with NA also appears not to be recognized in most cases. According to the current pathophysiological model of NA, an immunological trigger is necessary to initiate the disease process. Our data support the accuracy of this model.