scintillating scotoma

   Also known as flittering scotoma, fortification spectrum, fortification figure, "fortification of Vauban, geometrical spectrum, herringbone, Norman arch, telehopsia, and teichopsia. The term scintillating scotoma is indebted to the Latin noun scintilla (spark) and the Greek noun sko-tos (darkness). It was coined in or shortly before 1870 by the British physician and migraineur Hubert Airy (1838-1903), whose father was a migraineur as well. Airy's classical autodescription of the phenomenon runs as follows. "When it was at its height it seemed like a fortified town with bastions all around it, these bastions being coloured most gorgeously... All the interior of the fortification, so to speak, was boiling and rolling around in a most wonderful manner as if it was some thick liquid all alive." Today the terms scintillating scotoma, fortification spectrum, and the others mentioned above are used to denote a * geometric visual hallucination consisting of an extremely bright, sometimes coloured, zigzag line or 'fortification wall', which may begin near the fovea in one hemi-field and then spread out towards the periphery of that same hemifield without touching the vertical meridian. For a further description of this phenomenon, see the entry Fortification spectrum.

   References

   Airy, H. (1870). On a distinct form of transient hemiopsia. Philosophical Transactions of the Royal Society of London, 160, 247-264.

   Sacks, O. (1992). Migraine. Revised and expanded. New York, NY: Vintage Books.

   Wilkinson, F. (2004). Auras and other hallucinations: Windows on the visual brain. Progress in Brain Research, 144, 305-320.