[Case of ruptured middle cerebral artery bifurcation aneurysm presenting as putaminal hemorrhage without subarachnoid hemorrhage].

Ruptured aneurysms typically present as subarachnoid hemorrhage (SAH); however, they can also cause intracerebral hemorrhage (ICH) that can be mistaken for hypertensive hemorrhage. We report a rare case of a ruptured middle cerebral artery bifurcation aneurysm presenting as putaminal hemorrhage without subarachnoid hemorrhage (SAH). A 47-year-old man, with a past history of hypertension, presented with a decreased level of consciousness. Neurological examination revealed hemiparesis of the right side. A CT scan on admission demonstrated left putaminal hemorrhage without SAH. Three-dimensional CT and conventional angiograms demonstrated a superiorly directing aneurysm of the M1/M2 portion of the left middle cerebral artery (MCA). We performed aneurysmal clipping and hematoma evacuation. The postoperative course was uneventful. This case suggested that ruptured aneurysms situated on the middle cerebral artery can present as putaminal hemorrhage without SAH.