Late complications of radiosurgery for cerebral arteriovenous malformations: report of 5 cases of chronic encapsulated intracerebral hematomas and review of the literature

Abstract

Background: Chronic encapsulated intracerebral hematomas (CEIHs) are a rare, late complication of radiosurgery for intracranial AVM. We present 5 cases treated mostly by surgical excision and review the literature. Methods: Patients (age 39, 42, 36, 31, 62) presented with headache, paresthesia, hemiparesis or were asymptomatic. CEIHs presented 10 to 13 years (median 12 years) post radiosurgery. Three patients had demonstrated early radiation induced changes post radiosurgery. Angiographic cure, assessed with DSA, was present in all cases except 1 case with a small nidus remnant. MRI demonstrated mixed lesions with a solid enhancing part, organized hematoma and extensive surrounding edema while three cases had also a cystic component. Results: Excision of the CEIHs with complete or partial removal of the capsule was perfomed in 4 patients and resulted in marked clinical improvement. On patient was managed conservatively with administration of steroids as surgery was judged excessively hazardous with eventual stabilization of his symptoms. Conclusions: CEIHs are rare, late complications of radiosurgery for cranial AVM. They may be asymptomatic or provoke symptoms and may be preceded by early radiation induced changes. Complete removal of CEIHS is an effective treatment. Because of the long latency period of CEIHs, patients who had radiosurgery for brain AVMs should be followed by MRI at least 10 years even after complete obliteration.

Encapsulated Intracerebral Hematoma Presenting as Cerebral Abscess

“…CEIH remains rare, and due to its variable radiographic appearance, may be mistaken for a tumor or a brain lesion [1][2][3][4][5][6][7][8][9][10][11]. Recent case reports have shown CEIH occurrences as a late complication of AVM radiosurgery, with 37 cases described as of 2020 [5,10]. Based on the MRI findings of the patient, the primary differential diagnosis included abscess, tumor, and hematoma.…”

“…Chronic encapsulated intracerebral hematoma (CEIH) is difficult to diagnose because of its tendency to mimic other brain lesions [1][2][3][4]. Patients may develop CEIH after spontaneous intracerebral hemorrhage (ICH), and in more recent years, CEIH has been reported after radiosurgery for arteriovenous malformations (AVMs) [4][5][6][7][8][9][10][11].…”