A middle cerebral artery dissecting aneurysm manifesting solely with pain, following a vertebral artery dissecting aneurysm

A 41-year-old male had presented with severe neck pain and was diagnosed as having a left vertebral artery (VA) dissecting aneurysm. During the observation period, he suddenly suffered from a pain on his left temple. MR imaging revealed neither SAH nor cerebral infarction. MR angiography, computed tomographic (CT) angiography and cerebral angiography showed fusiform dilatation of the M1 portion of the left middle cerebral artery (MCA) which had been normal in the former study. The abnormality of the left MCA normalized on both MR and CT angiography 6 months after the second onset. Because of the chronological change of radiological findings compatible with the symptom, we diagnosed the second episode as a MCA dissecting aneurysm manifesting with isolated pain. Among the previous forty-four MCA dissecting aneurysms, all but one case presented with hemorrhagic or ischemic event. In addition, this is the only case of multiple dissecting aneurysms of VA and MCA manifesting with isolated pain.