Ten patients with migraine developed persistent positive visual phenom
ena lasting months to years. The complaints were similar in their simp
licity and involvement of the entire visual field and usually consiste
d of diffuse small particles such as TV static, snow, lines of ants, d
ots, and rain. Neurologic and ophthalmologic examinations were normal,
and EEGs were normal in eight of eight patients tested. MRI was norma
l in all patients except one who had nonspecific biparietal white matt
er lesions and another with a small venous angioma. Treatment of this
unusual complication of migraine was unsuccessful.