A case of vertebral dissecting aneurysm manifesting as subarachnoid hemorrhage following nuchal pain]

We report a case of subarachnoid hemorrhage (SAH) from vertebral dissecting aneurysm 4 days after first nuchal pain. The patient was a 46-year-old man with a sudden onset of nuchal pain. There were no obvious abnormalities detected on MR images in another hospital. Four days later, however, he was admitted to our hospital because of severe re-attack of nuchal pain. CT demonstrated moderate SAH and cerebral angiograms revealed right vertebral dissecting aneurysm. Proximal occlusion of the vertebral artery including its aneurysmal dilatation was performed using detachable coils. We strongly suspected that his initial symptom of nuchal pain was due to dissection of the vertebral artery itself, since the aneurysmal dilatation accompanied by intramural hematoma had been observed retrospectively in the initial MR imaging. The incidence of the vertebral dissecting aneurysm presenting with nuchal pain alone due to dissection is reported to be 7% in the literature. The prognosis of non-hemorrhagic vertebral dissecting aneurysm followed by delayed SAH is considered to be fatal. Therefore, careful investigations for differential diagnosis should be taken into account since the diagnostic possibility exists that non-hemorrhagic vertebral dissecting aneurysm would be manifested by a symptom of headache/nuchal pain alone.