Visual obscurations in children

Abstract

Migraine Approximately 10% of all children suffer migraine headaches, with a quarter experiencing a preceding visual aura. Auras can feature visual deficits (negative phenomena) and/or false images (positive phenomena). Negative phenomena are typically described as black spots in front of the eyes or as a partial blurring of vision. The most common positive phenomena are flashes of light (photopsias) and flickering zig-zag patterns (scintillating scotomas). These zig-zag patterns can expand outward to form obscurations likened to a wall around a city (fortification spectra). These phenomena are usually black and white, though they can be coloured. Other positive phenomena include visual illusions such as a feeling that objects have grown larger (macropsia) or smaller (micropsia). The onset of the aura occurs over a period of minutes and can persist for up to an hour before the onset of a migrainous headache (Box 1). The return to normal vision is typically gradual. There is often a family history of migraine. Unlike typical migraine, complicated migraine syndromes feature motor abnormalities and/or changes in consciousness level. However, these are not present at the onset of visual changes.