title: High prevalence of incidental brain findings in primary dysmenorrhoea.
abstract: BACKGROUND
  Primary dysmenorrhoea (PDM) is inexorably common. PDM women suffer from cramping pain in the lower abdomen that starts with menstruation and lasts for 24-72 h. Up to 90% of adolescent girls and more than 50% of menstruating women worldwide report suffering from it. Ten to 20% of PDM women describe their suffering as severe and distressing. However, nothing is known regarding the association of PDM with possible brain anomalies or abnormalities.
  
  
  METHODS
  High-resolution T1-weighted anatomical brain magnetic resonance images (MRI) were acquired for each subject and inspected for incidental findings (normal variants and abnormalities) as a routine procedure in our PDM-related multimodal neuroimaging studies. Altogether, 330 right-handed young women [otherwise healthy PDMs = 163; non-PDM healthy controls (HCs) = 167] were enrolled during the period of 2006-2014. Binomial proportion test was performed for between-group comparisons.
  
  
  RESULTS
  PDMs demonstrated significantly higher prevalence of overall incidental brain MRI findings (PDMs: n = 18, 11.0%; HCs: n = 6, 3.6%; p = 0.005) that should be ascribed to a preponderance of normal variants (PDMs: n = 16, 9.8%; HCs: n = 3, 1.8%; p = 0.001), especially cavum septum pellucidum. No significant between-group difference of abnormal findings was found (PDMs: n = 2, 1.2%; HCs: n = 3, 1.8%; p = 0.336).
  
  
  CONCLUSIONS
  We report here that otherwise healthy PDMs are associated with high prevalence of normal variants but not brain abnormalities. Our observations invite further epidemiological and neuroscientific studies.
authors.affiliation: Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: W C
authors.initials: WC
authors.lastname: Li
authors.affiliation: Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Integrated Brain Research Unit, Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taiwan.|Department of Education and Research, Taipei City Hospital, Taiwan.
authors.forename: C H
authors.initials: CH
authors.lastname: Tu
authors.affiliation: Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taiwan.|Department of Obstetrics and Gynecology, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: H T
authors.initials: HT
authors.lastname: Chao
authors.affiliation: Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Integrated Brain Research Unit, Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taiwan.|Department of Radiology, Taipei Veterans General Hospital, Taiwan.
authors.forename: T C
authors.initials: TC
authors.lastname: Yeh
authors.affiliation: Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Integrated Brain Research Unit, Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taiwan.
authors.forename: L F
authors.initials: LF
authors.lastname: Chen
authors.affiliation: Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Integrated Brain Research Unit, Division of Clinical Research, Department of Medical Research, Taipei Veterans General Hospital, Taiwan.
authors.forename: J C
authors.initials: JC
authors.lastname: Hsieh
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000473:pathology*; D004412:Dysmenorrhea / Q000150:complications*; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008279:Magnetic Resonance Imaging; D059906:Neuroimaging; D015995:Prevalence; D012688:Septum Pellucidum / Q000473:pathology; D055815:Young Adult