Ruptured Mycotic Aneurysm of the Distal Middle Cerebral Artery Manifesting as Subacute Subdural Hematoma
A 72-year-old male patient visited our hospital for headache and drowsiness. He slipped and suffered from blunt traumas to his head 10 days before his visit to the hospital. He showed right hemiparesis with a motor power of grade IV/V in the right upper and lower limbs. The initial Glasgow coma scale score was 12 (Eye response - 3, Verbal response - 4, Motor response - 5). He had no extracranial wounds and the vital signs were stable, but his body temperature was mildly elevated. The patient had a history of type 2 diabetes mellitus and hypertension, and he was a heavy alcoholic.\nEnhanced computer tomography (CT) of the brain showed subacute subdural hematomas on both fronto-parietal areas and an enhancing nodule in the left parietal area (). No signs of scalp contusion and skull fracture were found. CT angiography revealed that the enhancing nodule was a saccular aneurysm located at the M4 segment of the left middle cerebral artery (MCA). Cerebral angiogram showed 2 aneurysms; one located at the distal left MCA and the other at the bifurcation of the left MCA ().\nLaboratory studies revealed an elevated erythrocyte sedimentation rate (ESR, 49 mm/hr), white blood cell count (WBC, 12,990/µL) and C-reactive protein (CRP, 9.28 mg/L), but other hematological and biochemical parameters were within normal range. Blood cultures were negative and there was no evidence of infective endocarditis in the echocardiography.\nIntravenous ceftriaxone 1 g every 12 hours was started. His symptoms improved gradually over the next few days. The enhanced CT 10 days after admission revealed disappearance of the aneurysm located at the M4 segment and partial resolution of SDH (). Additional angiography was performed 20 days after antibiotic therapy. It revealed complete resolution of the aneurysm at the left distal MCA (). Antibiotics were continuously given for 4 weeks with moderate improvement of his symptoms and the patient was discharged. Because the aneurysm located at the bifurcation of the left MCA was small and had no interval change, we decided to observe it in our outpatient department.