Migraine-Like Positive Visual Phenomena Related to Focal Cortical Lesions with Undetectable Visual Field Defects.

Migraines are commonly associated with a visual aura that has a characteristic clinical presentation. Cortical lesions within or in close proximity to the retrochiasmal visual pathways may also present in a manner that mimics migrainous visual phenomena and, in some cases, may be too small to manifest with a visual field defect on formal testing. We present 4 patients (3 females and 1 male) with an average age of 48.5 (range 28-67) years who had migraine-like visual disturbances related to a right temporal meningioma, occipital cavernoma, occipital lobe infarction, and demyelination in the optic radiations, which was the presenting sign of multiple sclerosis. No patient underwent neurosurgical intervention, and 1 patient (occipital lobe infarct) had complete resolution of the symptom after initial presentation. All patients had normal visual fields at follow-up and no thinning evident on optical coherence tomography. Our cases emphasize the importance of a history in assessing patients with transient positive visual phenomena and identify pathology that may present without visual field defects. Clinical features that should raise a doubt about a diagnosis of migraine visual aura include the absence of headache, brief visual disturbance lasting <5 min or those lasting >60 min, and age >40, especially with no past medical history of migraine.