Warning headache of subarachnoid hemorrhage and infarction due to vertebrobasilar artery dissection

Objectives: The authors describe the clinical features of headache in patients with vertebrobasilar artery dissection (VBAD) and emphasize the importance of recognition of warning headaches preceding subarachnoid hemorrhage. Headache in VBAD is already recognized, but the natural history and clinical features of the warning headache have not been well elucidated. Methods: The clinical features of 30 patients with VBAD were analyzed retrospectively. Results: Of the 30 VBAD patients, 16 presented with subarachnoid hemorrhage and 14 with ischemia. Headache (without any other symptoms or signs) was detected in 70% of patients with subarachnoid hemorrhage and 50% of patients with infarction. The headache started acutely, was localized to the occiput or nape of the neck, was sharp and severe in intensity, and was different from any previously experienced headaches. The interval from onset of headache to diagnosis of subarachnoid hemorrhage or infarction was 1 to 10 days. Three patients had sudden severe warning headaches without any evidence of subarachnoid hemorrhage at initial presentation and deteriorated within 24 hours due to subarachnoid hemorrhage, demonstrated later on computed tomography. Angiographic findings of patients with warning headaches were nonspecific compared with those of patients without headache. Conclusions: The 'present study confirms a high frequency of headache in patients with VBAD. Sudden severe occipital and nuchal pain, even without subarachnoid hemorrhage or any neurologic deficit, should be considered as a warning sign of subarachnoid hemorrhage. Computed tomography, magnetic resonance imaging, and magnetic resonance angiography should be performed urgently for screening of patients with a warning headache to prevent resultant life-threatening major vascular events.