[Delayed white matter lesion after mechanical thrombectomy for middle cerebral artery occlusion with Libman-Sacks endocarditis].

A 59-year-old woman presented with right hemiparesis and was transported from outside hospital. MRI revealed acute infarction and the left middle cerebral artery M2 occlusion. Intravenous infusion of recombinant tissue-type plasminogen activator, and mechanical thrombectomy (MT) were performed. The cause of cerebral infarction was diagnosed as Libman-Sacks endocarditis. She discharged without sequelae. After 10 months later, she presented with mild cognitive decline, and MRI showed new white matter lesion in left deep white matter. In magnetic resonance spectroscopy, the lesion showed an increased rate of choline/creatine, and a decreased rate of N-acetylaspartate/creatine, elevated lactate peak. When new higher brain dysfunction presented after recanalization by MT, it might be related to the delayed white matter lesion.