Incidence of polyneuropathy in Utrecht, the Netherlands.

Abstract

Ascertain the incidence of cryptogenic axonal polyneuropathy (CAP) and how this relates to the overall incidence of polyneuropathy. Electronic diagnostic registries of all hospital-based neurologic practices in the province of Utrecht (population 1,224,852 = 7.4% of the Dutch population) were consulted in 2010 to identify incident cases with polyneuropathy. Medical files were reviewed to specify the final diagnosis. Age-adjusted incidence rates for the Netherlands were calculated using national age-specific population figures. The overall incidence of polyneuropathy was 77.0/100,000 person-years (95% confidence interval 71.1-82.8) in persons aged 18 years and older. Diabetic polyneuropathy (32%), CAP (26%), toxic polyneuropathy (14%), and immune-mediated polyneuropathy (9%) were the most frequent diagnoses. The incidence of CAP was 31.6/100,000 person-years (95% confidence interval 27.0-36.3) in persons aged 40 years and older. The incidence of polyneuropathy increased with age, as well as the proportion of patients diagnosed with CAP: 12% (40-49 years), 20% (50-59 years), 28% (60-69 years), 32% (70-79 years), and 35% (≥80 years) (χ(2) test, p = 0.005). The chance of establishing an etiologic diagnosis in patients presenting with a polyneuropathy decreases with age. Given the aging population, polyneuropathy in general and CAP in particular will pose a growing health care problem.