A 49 year old woman reported an attack of transient neurological dysfu
nction associated with unilateral headache. A prominent feature of the
aura was a period of complete achromatopsia, so that the visual scene
was experienced in monochrome. The episode developed to include featu
res of prosopagnosia and spatial agnosia before resolving completely.
Other episodes of transient neurological dysfunction followed at regul
ar intervals until prophylactic antimigrainous therapy was initiated.
Four vessel cerebral angiography and MRI of the brain were normal. Pos
sible causes of this unusual migrainous aura are discussed with refere
nce to current concepts of cerebral localisation.