Bickerstaff described a typical sequence of neurological events that involved total blindness and sensorial clouding that was seen frequently in adolescent women. Often the patients experience a state of confusion. These symptoms often persist for 20 to 30 minutes and are generally followed by a throbbing occipital headache. The altered sensorial effects may last up to 5 days and be marked by confusion. Originally the term basilar artery migraine was used but since spasm of the basilar artery may not be the mechanism of the attacks, the term basilar migraine is preferred.
Many cases have basilar attacks intermingled with attacks with typical aura.
Basilar attacks are mostly seen in young adults. It was noted that as the basilar attack developed and the patient became unconscious, repetitive spikes at 4 per second developed in both occipital regions and persisted for 40 seconds after the flash stimulation ceased. This phenomenon leads one to consider the source of the attacke is cerebral hyperexcitability such as is most often seen in epilepsy. Brainstem symptoms as described above are not limited to basilar migraine and may be seen in other migraine syndromes associated with internal artery perfusion. Migraine is often accompanied by mltifocal dysfunction as is seen in ophthalmoplegic and hemiplegic migraine.