[Vertebral artery dissecting aneurysm presenting with isolated pain and showing repeated morphological changes over the short term: a case report].

Vertebral artery (VA) dissecting aneurysm (VADA), which presents with headache and neck pain as the only manifestations, is an uncommon pathology, but is increasingly recognized as a cause of posterior circulation stroke in young adults. We report a case of VADA with isolated occipital headache at the time of onset and treatment using an endovascular approach. A 58-year-old man was admitted to our hospital with left occipital headache. Cranial magnetic resonance imaging (MRI) showed neither subarachnoid hemorrhage(SAH)nor cerebral infarction, but magnetic resonance angiography (MRA)revealed left VADA. Conservative treatment including pain relief and blood pressure control was provided. After 2 weeks, the dissecting lesion showed spontaneous improvement and occipital headache was gradually improving. However, 4 months after onset, the VADA showed growing aneurysmal dilatation. We therefore performed endovascular surgery (coil embolization with parent artery occlusion). Symptoms improved, and the postoperative course was uneventful. Although the natural history of VADA with isolated headache remains unclear, endovascular treatment should be considered for patients with growing aneurysmal dilatation, since the prognosis for patients with subsequent SAH is very poor.