title: Critical flicker frequency in migraine. A controlled study in patients without prophylactic therapy.
abstract: The critical flicker frequencies (CFF) of individuals with migraine with and without aura were determined and compared to those of normal controls. Twenty-six migraine patients, 12 with aura and 14 without aura and 30 healthy controls were included. Migraineurs were tested during a migraine-free period, through both the continuous flicker method (CFM) and the forced choice method (FCM). Migraineurs presented a mean flickering fusion threshold lower than healthy controls with the CFM (40.45 vs. 44.33, respectively; P = 0.019) and with the FCM (34.16 Hz vs. 38.5 Hz, respectively, P = 0.019). Both groups of migraineurs had significantly lower thresholds as compared to controls, migraineurs with aura presenting the lowest thresholds for the fusion of flickering (P = 0.008 and P = 0.0001 with the CFM and the FCM, respectively). Results confirmed and extended previous observations of abnormal flicker fusion thresholds in migraineurs. We hypothesize that this finding might be related to a shorter cortical stimulation silent period.
authors.affiliation: Headache Unit, Neurology Division, Internal Medicine Department, Hospital de Clínicas da Universidade Federal do Paraná, Curitiba, Brazil. cefaleia@hc.ufpr.br
authors.forename: P A
authors.initials: PA
authors.lastname: Kowacs
authors.forename: E J
authors.initials: EJ
authors.lastname: Piovesan
authors.forename: L C
authors.initials: LC
authors.lastname: Werneck
authors.forename: H
authors.initials: H
authors.lastname: Fameli
authors.forename: A C
authors.initials: AC
authors.lastname: Zani
authors.forename: H P
authors.initials: HP
authors.lastname: da Silva
mesh_terms: D000328:Adult; D000700:Analgesics / Q000627:therapeutic use; D005260:Female; D005425:Flicker Fusion / Q000502:physiology*; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000188:drug therapy / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods*
chemical_list: D000700:Analgesics