[A case of cerebral infarction treated with tissue-plasminogen activator exhibiting prolonged cerebral edema for more than 1 month].

A 62-year-old man with hypertension and diabetes mellitus controlled by medication suddenly noticed slight hemiparesis and was admitted to our hospital. Tissue-plasminogen activator (t-PA) was administered as his NIHSS was 6 and there were no contraindications. His symptoms completely resolved after t-PA injection. He was discharged on Day 9 without neurological deficits despite minor bleeding being detected in a small, low-density area in the right post-central region on CT. However, the hemiparesis gradually recurred subsequently and the low-density area had increased. He was readmitted on Day 38 due to deterioration of symptoms and enhanced CT imaging exhibited a large, low-density area in the central parasagittal region with enhancement was seen. An open biopsy was performed on Day 52 for diagnostic purposes. Histology demonstrated increased small vessels surrounded by many non-specific inflammatory cells and abundant reactive astrocytes. To date, reports of prolonged cerebral edema lasting more than 1 month after cerebral infarction are rare. This condition may be due to angiogenesis induced by t-PA. Another reason may have been the location, i.e., the parasagittal region, which is the most common area for severe cerebral edema after gamma knife surgery.