<unk> s are most commonly caused by cortical spreading depression, a pattern of changes in the behavior of nerves in the brain during a migraine. Migraines, in turn, may be caused by genetic influences and hormones. People with migraines often self-report triggers for migraines involving stress or foods, or bright lights. While monosodium glutamate (MSG) is frequently reported as a dietary trigger, scientific studies do not support this claim. The Framingham Heart Study, published in 1998, surveyed 5,070 people between ages 30 and 62 and found that<unk> s without other symptoms occurred in 1.23% of the group. The study did not find a link between late-life onset<unk>  and stroke.
Scintillating scotoma
Persistent aura without infarction
Hutchinson's pupil
Retinal migraine
Cryptophthalmos
Macular corneal dystrophy
Persistent pupillary membrane
Nephroptosis