[Rare and atypical forms of migraine]

There are three categories of rare forms of migraine headache. Atypical aura can raise difficult diagnostic questions due to their clinical expression (visual or sensorial illusions and hallucinations), their mode of onset (sudden aura, developing in less than 4 minute), their duration (prolonged aura lasting more than 60 minutes), and the lack of an accompanying headache. Differential diagnostics include partial epilepsy or AIT, requiring careful search for the underlying cause. Rare migraine syndromes are separate clinical entities, most of which are recognized by the International Headache Society (IHS). These syndromes include basilar migraine, familial hemiplegic migraine, ophthalmoplegic migraine and the exceptional retinal migraine. Confusional migraine, usually observed in children, is no individualized by the IHS but can be included here. For secondary migraines there is a triggering factor leading to migraine in patients with no history of migraine previously. These include post-traumatic migraine and cervical migraine as well as migraine occurring with epileptic seizures and rare symptomatic migraine headache disclosing a general disease or an intracranial neurological lesion.