ObjectiveNeuralgic amyotrophy is considered a rare peripheral nervous system disorder but in practice seems grossly under recognized, which negatively affects care for these patients. In this study we prospectively counted the one-year incidence rate of classic neuralgic amyotrophy in a primary care setting. MethodsIn a prospective cohort study during the year 2012 we registered all new cases of neck, shoulder or arm complaints from two large primary care centers serving a population of 14,118. Prior to study, general practitioners received a short training on how to diagnose classic neuralgic amyotrophy. Neuralgic amyotrophy was defined according to published criteria irrespective of family history. Only patients with a classic phenotype were counted as definite cases. After inclusion, patients with suspected neuralgic amyotrophy who had not yet seen a neurologist were offered neurologic evaluation for diagnostic confirmation. ResultsOf the 492 patients identified with new onset neck, shoulder or arm complaints, 34 were suspected of having neuralgic amyotrophy. After neurologic evaluation the diagnosis was confirmed in 14 patients. This amounts to a one-year incidence rate for classic neuralgic amyotrophy of 1 per 1000. Data Availability Statement: No centralized data collection was available for this study. Data were collected in an anonymized digital datafile and stored locally by the study group. The primary data file for this study is available as S1 Datafile.Funding: This study was sponsored by an unsolicited and unconditional gift from the Dutch Rare Diseases Fund (Stichting Zeldzame Ziekten Fonds; www.zzf.nl) and the ZABAWAS Foundation (www. zabawas.nl). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ConclusionsOur findings suggest that neuralgic amyotrophy is 30-50 times more common than previously thought. Unawareness of the disorder and its clinical presentation seems the most likely explanation for this difference. An incidence rate of 1 per 1000 and the long-term sequelae many patients suffer warrant more vigilance in diagnosing the disorder, to pave the way for timely treatment and prevent complications.