How do I distinguish migraine aura from TIA attack?]

Migraine aura is almost always a visual disturbance involving "positive" (rippling, stars) and "negative" (visual field defect) phenomena. It expands and gradually vanishes within 5 to 60 minutes. Evolution of symptoms and positivity are typical for migraine. TIA appears more abruptly and is usually of shorter duration. Negativity is typical for it, i.e. part of the visual field, speech, eye movement, ability to swallow, sensation or muscle strength disappear without the above mentioned features of migraine. In migraine, aura is usually followed by headache, whereas in TIA headache is less frequent.