Migraine et troubles de la vision
This (greatly speeded up) cartoon of a classic
migrainous scintillating scotoma shows its
development from a small paracentral bright spot to
an enlarging bright, curved, zig-zag line (the
scintillation) in the left visual field. Inside the line,
vision is dark and obstructed (the scotoma). The
interval from the onset to the full enlargement of the
zig-zag line is usually about 10-20 minutes. Soon after
its full development, the image disappears. This
phenomenon has been called a "fortification spectrum"
because of its resemblance to aerial views of the
walls surrounding medieval cities (admittedly not
very apparent in this cartoon). Of his own spectra,
Hubert Airy (1854) said that "...at its height it seemed
like a fortified town with bastions all round it, these
bastions being coloured most gorgeously...All the
interior of the fortification, so as to speak was boiling
and rolling about in a most wonderful manner as if it
was some thick liguid all alive."