title: Asymmetry of visual function in migraine with aura: correlation with lateralisation of headache and aura.
abstract: BACKGROUND
  Asymmetry of visual phenomena and headache is an important feature of migraine with aura.
  
  
  METHODS
  This asymmetry was explored by assessment of visual illusions, hemifield spatial contrast detection (HCD) and hemifield pattern reversal visual evoked potentials (HVEPs) in 47 migraineurs with aura (MA), who were not taking prophylactic medications, and 62 controls with the same age range (16-59).
  
  
  RESULTS
  Illusions were greater and HCD was poorer in MA than in controls. There were no group differences with respect to P100 amplitude. The longer the duration of migraine the poorer the HCD. When the aura was consistently unilateral it was associated with greater illusions, reduced HCD and reduced hemifield P100 amplitude. These findings were not related to the side of headache.
  
  
  CONCLUSIONS
  The lateralised changes suggest that the visual dysfunction occurs at a cortical level, and the correlation with the side of the aura suggests that dysfunction is most likely to occur in an area of preexisting anomaly of neural function.
authors.affiliation: Department of Clinical Neurophysiology, West London Neurosciences Centre, Imperial College Healthcare NHS Trust and Charing Cross Hospital, London, UK. n.khalil@imperial.ac.uk
authors.forename: Nofal M
authors.initials: NM
authors.lastname: Khalil
authors.forename: Alessia
authors.initials: A
authors.lastname: Nicotra
authors.forename: Arnold J
authors.initials: AJ
authors.lastname: Wilkins
mesh_terms: D000293:Adolescent; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology; D005074:Evoked Potentials, Visual / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007088:Illusions / Q000502:physiology*; D008875:Middle Aged; D020325:Migraine with Aura / Q000503:physiopathology*; D014793:Visual Cortex / Q000503:physiopathology*; D055815:Young Adult