Migraine with aura: The "fortification spectra"
The most frequent type of aura preceding the migraine headache is the visual one. Its pathogenic mechanism is identified with the so-called "spreading depression" described by Leao, that is a cortical irritation followed by a depolarising wave with transient depression of neuronal activity, moving through the occipital lobe at a 2-3 mm/min speed.
The visual perception of the migraineur can be variegated, the most common being a zig-zag pattern of luminous lines. This was compared to Reinassance fortifications by John Fothergill (1712-80). In 1870 Hubert Airy, reporting on his own attack of migraine with aura, compared the visual disturbance to a fortified town with its bastions of a colourful appearance. Moreover, realising the illusory nature of these images, he called them "fortification spectra". Later on, William Gowers (1845-1915), with reference to "its projecting and reintrant angles bearing resemblance to the plan which the French engineer Vauban first described as the most effective for the defence of a fortress", introduced the term "fortification of Vauban", that since then has been largely used.
Historically, these kinds of fortifications were first developed in early sixteen century in Italy, when medieval circular towers were substituted with the lower and thicker bastions, to face the destroying power of the new mobile siege guns. Only later Sébastien Le Prestre De Vauban (1633-1707), at the service of Louis XIV, the Sun King, greatly contributed to the development of this branch of military engineering.
The first person who extensively applied this defensive system was Michele Sanmicheli (1484-1559), a Venetian military engineer. Since the beginning of the sixteen century he protected with such a building technique the most important towns of the Serenissima.
Therefore, with reference to the visual aura, the eponime "fortifications spectra of Sanmicheli" should be substituted for that "of Vauban".
Session IX -- Early Neurosciences
Sixth Annual Meeting of the International Society for the History of the Neurosciences (ISHN) and