title: Incidence of pediatric Horner syndrome and the risk of neuroblastoma: a population-based study.
abstract: OBJECTIVE
  To describe the incidence of pediatric Horner syndrome and the risk of occult malignancy in a population-based cohort.
  
  
  METHODS
  The medical records of all pediatric patients (aged <19 years) residing in Olmsted County, Minnesota, who received diagnoses of Horner syndrome from January 1, 1969, through December 31, 2008, were retrospectively reviewed.
  
  
  RESULTS
  Horner syndrome was diagnosed in 20 pediatric patients during the 40-year period, yielding an age- and sex-adjusted incidence of 1.42 per 100 000 patients younger than 19 years of age (95% confidence interval [CI], 0.80-2.04). Eleven of the 20 patients (55%) had a congenital onset, for a birth prevalence of 1 in 6250 (95% CI, 3333-10 000), while the remaining 9 (45%) had acquired syndromes. Seven of the 11 (63.6%) patients with congenital cases had a history of birth trauma, while the remaining 4 (36.4%) had no identifiable cause. Six of the 9 (66%) acquired cases occurred following surgery or trauma, while the remaining 3 (33%) had no known etiology. None of the 20 patients (95% CI, 0.0%-16.8%) were found to have a neuroblastoma or other malignancy during a mean follow-up of 56.5 months (range, 0-256.9 months).
  
  
  CONCLUSIONS
  The incidence of pediatric Horner syndrome in this population was 1.42 per 100 000 patients younger than 19 years, with a birth prevalence of 1 in 6250 for those with a congenital onset. Birth, surgical, or other trauma occurred in 13 (65%) of the patients, while none were found to have an underlying mass lesion, suggesting a need for reappraising current recommendations for extensive evaluations in these patients.
authors.affiliation: Mayo Clinic College of Medicine, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Smith
authors.forename: Nancy
authors.initials: N
authors.lastname: Diehl
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Leavitt
authors.forename: Brian G
authors.initials: BG
authors.lastname: Mohney
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006732:Horner Syndrome / Q000151:congenital / Q000453:epidemiology* / Q000235:genetics; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008910:Minnesota / Q000453:epidemiology; D009447:Neuroblastoma / Q000453:epidemiology*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution