Unusual visual symptoms in a patient with bilateral vertebral artery dissection: a case report.

We present a previously unreported set of symptoms in a patient found to have bilateral vertebral dissections. Although visual symptoms are common in vertebral dissection, their pattern does not typically mimic those that commonly precede or accompany migraine headache. When they do occur, they usually take the form of diplopia or blurred vision. The patient we describe had visual symptoms that varied over three episodes of headache and included transient visual field loss and scintillations ("lightning bolts"), both common in migraine. However, our patient's new visual symptoms represented a change in pattern from those that had accompanied her previous migraines. This detailed history-taking prompted an evaluation for an etiology other than migraine and prevented a further delay in diagnosis and treatment.