This page discusses some variants of migraine that are commonly confused with epilepsy.
Basilar migraine was originally called basilar artery migraine and has also been called Bickerstaff’s syndrome.37 Originally believed to be mainly a disorder of adolescent girls, it affects all age groups and both sexes, with the usual female predominance. The aura often lasts less than 1 hour and is usually followed by a headache. A hemianoptic field disturbance can rapidly expand to involve both visual fields, leading, at times, to temporary blindness. The visual aura is usually followed by at least one of the following symptoms: ataxia, vertigo, tinnitus, diplopia, nausea and vomiting, nystagmus, dysarthria, bilateral paresthesia, or a change in the levels of consciousness and cognition. If marked, these alterations in consciousness define confusional migraine.
The diagnosis of basilar-type migraine should be considered in patients with paroxysmal brain stem disturbances. This type of migraine may be difficult to differentiate from simple or complex partial seizures and the postictal state. The aura symptoms described previously are often, but not always, followed by a severe, throbbing occipital headache and vomiting. Although attacks are usually infrequent, they can last for 1 to 3 days. These headaches can be very frightening and difficult to diagnose. On occasion, the attacks can lead to cardiac arrhythmias and brain stem stroke. The differential diagnosis, besides occipital lobe epilepsy, includes posterior fossa tumor or malformation, urea cycle defects, and mitochondrial disorders.38
Confusional migraine3,39 is characterized by a typical migraine aura, a headache (which may be insignificant), and confusion, which may precede or follow the headache. During the confused period, the patient is inattentive and distracted and has difficulty maintaining speech and other motor activities. The EEG may be abnormal during the attack. Agitation, memory disturbances, obscene utterances, and violent behavior have been reported. Single attacks are most common; multiple attacks are rare. Both may be triggered by mild head trauma. A more profoundly disturbed level of consciousness may lead to migraine stupor, which can last from hours up to 5 days. The confusional state is usually followed by sleep, resembling postictal depression of mental status.
Confusional migraine may be difficult to diagnose. The differential diagnosis includes drug ingestion, metabolic encephalopathies (e.g., Reye’s syndrome, hypoglycemia), viral encephalitis, and acute psychosis. Acute confusional states also occur during complex partial seizures and the postictal state. The patient may be delirious, hyperactive, restless, and, on occasion, combative. Acute migraine confusional states may recur over a period of days or months and then evolve into typical migraine episodes. A history of typical migraine aura supports a diagnosis of migraine.
Benign paroxysmal vertigo of childhood may be a migraine equivalent. It is characterized by the sudden onset of brief attacks of severe vertigo in an otherwise healthy child. Children with this disorder cannot stand. They lie silently on the floor or wish to be held. The spells are brief, lasting only a few minutes and tending to recur at irregular intervals over a period of 6–12 months. Although headache may not be present at the onset, as the disorder evolves, the vertigo may be replaced by attacks of headache and vomiting, facilitating diagnosis.
When simple partial seizures give rise to vertigo, vertigo is usually less prominent than in migraine.
Migraine aura can occur without headache,40 although, in this setting, diagnosis is more difficult. These periodic neurologic phenomena (i.e., scintillating scotomata or recurrent sensory, motor, or mental phenomena) should be accepted as migraine only after a full investigation. Headache occurring in association with some attacks helps confirm the diagnosis.30 Ziegler and Hassanein11 reported that 44% of their patients who had headache with aura had aura without headache at some time.
Late-life migrainous accompaniments are characterized by attacks of aura without headache, beginning in late life.41,42 Many patients have a history of migraine in early or midlife, often with an attack-free hiatus. Because focal neurologic defects occur without headache, they can be confused with transient ischemic attacks or seizures. Late-life migrainous accompaniment remains a diagnosis of exclusion.
Reviewed and revised April 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.
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