The characteristic migrainous teichopsia is a hallucination beginning as a small C-shaped form, with its open side toward the midline. This form gradually expands and moves laterally over about 20 minutes until it disappears in the periphery. The positive phenomena may be followed by a period of visual field depression, even a complete homonymous hemianopsia. When headache occurs, it usually begins as the visual aura is resolving. Especially in young patients, the headache may be exquisitely painful, hemicranial, and accompanied by nausea, vomiting and sensitivity to light and sound.
Some patients suffer the headache for days, with no relief even during sleep.
Acephalgic migraine occurring for the first time in an elderly patient heralds vertebrobasilar insufficiency. Although the visual loss may be frightening to the patient, the prognosis for retaining vision is usually good with aspirin prophylaxis. A migraine may not require any workup. Sudden visual loss is a serious symptom which can indicate impending morbidity or even mortality. Thoughtful analysis after a careful history and examination can play a significant part in ensuring a good outcome.