title: Does the menstrual cycle influence the motor and phosphene thresholds in migraine?
abstract: OBJECTIVE
  The excitability of the visual and motor cortical areas is altered in migraineurs. Controversial results of previous studies on cortical excitability may depend on the hormonal status of female subjects. The present study aimed to determine whether the different phases of the menstrual cycle influence the phosphene thresholds (PT) and resting motor thresholds (RMT) in migraineurs.
  
  
  METHODS
  Thirty-two migraine patients participated in this study. Three to six PT and RMT measurements were done in headache-free intervals during the follicular, middle and luteal phases of the female cycle, or in active dosage and withdrawal phases in patients who were taking low dosage oral contraceptives.
  
  
  RESULTS
  Generally, PTs showed higher individual variabilities than RMTs. Additionally, we have observed that the RMTs and PTs were significantly independent from hormonal changes. However, patients who were taking a low dosage of oral contraceptives had lower PTs compared with patients who were not taking oral contraceptives. RMTs show the opposite tendency.
  
  
  CONCLUSIONS
  The results imply that PTs and RMTs can be reliably measured independently from the menstrual hormone status in female migraineurs.
authors.affiliation: Department of Clinical Neurophysiology, Georg-August University, Göttingen, Germany. klara.boros@med.uni-goettingen.de
authors.forename: K
authors.initials: K
authors.lastname: Boros
authors.forename: C
authors.initials: C
authors.lastname: Poreisz
authors.forename: W
authors.initials: W
authors.lastname: Paulus
authors.forename: A
authors.initials: A
authors.lastname: Antal
mesh_terms: D000328:Adult; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle / Q000502:physiology*; D008875:Middle Aged; D008881:Migraine Disorders / Q000503:physiopathology*; D010719:Phosphenes / Q000502:physiology*; D012684:Sensory Thresholds; D012815:Signal Processing, Computer-Assisted; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult