VISUAL-SYSTEM DYSFUNCTION IN MIGRAINE - A REVIEW OF CLINICAL AND PSYCHOPHYSICAL FINDINGS

This paper reviews both clinical and experimental literature relating to visual dysfunction in migraine, starting with the eye and progressi ng via the retina and visual pathways to the visual cortex. Migraine i s associated with (i) a pupillary sympathetic hypofunction, and (ii) a cortical hypersensitivity to visual stimuli (perhaps only in migraine with aura), the pathogenesis of which remains to be determined. Vario us hypotheses are discussed, and it is proposed that the methods of vi sual psychophysics may represent a useful approach in the future study of cortical hyperexcitability in migraine. Paradoxically, little rese arch has been directed towards understanding (i) the photophobia of mi graine attacks, and (ii) how migraine may be triggered by visual stimu li. Research aimed at elucidating the mechanisms of these phenomena ma y enhance understanding of the pathogenesis of migraine.