Incidence of ulnar neuropathy at the elbow in the province of Siena (Italy)

Abstract

Background: Although ulnar neuropathy at the elbow (UNE) is the second most frequent focal peripheral neuropathy of the upper limb after carpal tunnel syndrome (CTS), no figures on its prevalence or incidence in the general population have been reported.

Objective: To determine the incidence of UNE in a general population.

Methods: Retrospective study to identify newly diagnosed cases on the basis of clinical symptoms or signs and slowing of motor conduction velocity of the ulnar nerve across the elbow or surgical evidence of nerve compression in the elbow region. In the 5-year period from 1995 to 1999, cases among residents in Siena Province (Italy) were identified from medical records of electromyographic services of Local Health District no. 7 and from hospital medical records coded ICD 354.2, 04.49 and 04.6. Siena province has a population of 251,930.

Results: In the 5-year period, 311 cases (112 women and 199 men, mean age 56 years, range 15-86) were identified. The mean annual crude incidence was 24.7 cases per 100,000 person-years, and the standardized incidence was 20.9. The sex-specific incidences were 32.7 for men and 17.2 for women. The mean annual crude and sex-specific incidences remained constant during the study period. The age-specific incidences of whole population and both genders showed an increasing trend with decade of age. The incidence of "possible", "probable" and "definite" UNE cases, classified according to level of motor conduction velocity anomalies and evidence of surgical compression of the ulnar nerve at the elbow, was 4.3, 10.6, and 9.8, respectively. The residents of a health subdistrict where manual work is dominant had a higher male-specific incidence (57.1) than other areas.

Conclusions: This is the first published study on the incidence of UNE. The incidence was higher in males than females and about one-thirteenth that reported for CTS in part of the present geographic area.