Case Reports: Two Different Onset Types of Chronic Encapsulated Intracerebral Hematoma related to cerebrospinal fluid perfusion identified prior to and following surgery

Hypertensive intracerebral hemorrhage rarely develops into chronic encapsulated intracerebral hematoma (CEIH). We encountered 2 cases of CEIH, one with initial CEIH and the other with CEIH following minimally invasive endoscopic surgery for hypertensive intracerebral hemorrhage. Case 1 was a 46-year-old man with Glasgow Coma Scale (GCS) 12 (E4V3M5), complete hemiplegia, and motor aphasia who was brought to our hospital. A head computed tomography scan showed a left putaminal hemorrhage, and he was treated conservatively. However, because the hematoma enlarged and cerebral herniation appeared, we performed endoscopic hematoma removal. His paralysis improved and he transferred to a convalescent hospital with modified Rankin Scale 2. Case 2 was an 84-year-old man with GCS 9 (E3V2M4), right conjugate deviation, and complete hemiplegia who was brought to our hospital. We performed endoscopic hematoma removal. Because of gradual regrowth of the hematoma and cerebral herniation, endoscopic hematoma removal was performed again on day 12 after surgery. His consciousness improved postoperatively, and he was transferred to a convalescent hospital. The pathogenesis of CEIH is still not known, and we newly suggest the involvement of pia mater collapse and cerebral spinal fluid accumulation. We report the effectiveness of minimally invasive endoscopic surgery and reconsider the mechanism of CEIH based on a literature review.