Since there is no pathognomonic laboratory test for migraine, its delineation must be clinical.
Attacks are commonly unilateral and are usually associated with anorexia, nausea and vomiting.
In some cases, they are preceded by, or associated with neurological and mood disturbances. Migrainous infarction 1.7 Migrainous disorder not fulfilling above criteria 1. The fact that many migrainous headaches are not unilateral illustrates that etymological derivations are misleading, since newer knowledge renders the original meaning inaccurate for scientific precision. While its presence is helpful in the diagnosis of migraine, most migrainologists would agree that it is not essential. In the same patient, different attacks may be unilateral or generalized.