Is familial hemiplegic migraine a hereditary form of basilar migraine?

We studied aura symptoms in 83 patients from 6 unrelated families suffering from familial hemiplegic migraine. Fifty-five of the patients reported symptoms that allowed us to categorize them as basilar migraine (BM) patients, in accordance with the International Headache Society (IHS) criteria. In a control group of 33 patients suffering from migraine with aura and 33 patients suffering from migraine without aura, 9 patients complained of vertigo, and only one patient of diplopia during one of her attacks. None of these control patients fulfilled the IHS criteria for BM. We suggest that familial hemiplegic migraine and BM may share certain pathophysiologic mechanisms, which may consist of a (genetically determined) disturbance of basilar artery blood flow.