It's Snowing! Four Cases of Persistent Migrainous Visual Aura Without Infarction

Persistent migrainous visual aura is described as persistent visual phenomena lasting more than seven days and without evidence of infarction. It was reported under several names, like sustained visual aura, persistent positive visual phenomena and migraine aura status. There are around twenty cases reported. The pathophysiology of the symptom is unknown, although it is thought to involve neurovascular changes