No leg to stand on

“She was bisected, and half of her was missing.” This is how Dr Oliver Sachs perceived a nurse during the aura of a migraine. It is described in his book A Leg to Stand On, in which he explains how this experience is due to a transient hemianopia that he experiences as a migraine begins.1

I too have migraine with visual auras, which occur only in the left side of my visual field. Although I usually experience fortification spectra within the left hemi-field, I realised recently that occasionally I have a left homonomous hemianopia …