Delayed Leukoencephalopathy and Foreign Body Reaction After Endovascular Treatment in Patients With Intracranial Aneurysms and Aneurysmal Subarachnoid Hemorrhage—A Systematic Review of the Literature

Background: Delayed leukoencephalopathy and foreign body reaction are rare complications after endovascular treatment of intracranial aneurysms. However, cases are increasingly being described, given the rising case numbers and complexity. Methods: Clinical presentation, differentials, diagnostics, treatment, and formerly published data were reviewed in light of available cases. A systematic search of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Results: This article provides an extensive literature review of previously described cases, and discusses the causes and management of this rare and delayed complication by referring to 17 articles on this topic, with a total of 50 cases with sufficient data in the literature. Furthermore, we present the case of a 53-year-old female patient with subarachnoid hemorrhage from a large anterior communicating artery aneurysm with tortuous cervical vessels who was treated with endovascular coiling and has suffered delayed leukoencephalopathy 6 weeks after discharge. Diagnostics, treatment, and clinical course of this rare complication are presented on this case and based on formerly published literature. The patient timely recovered under high dose corticosteroid treatment and follow up MRI showed almost complete remission of the described lesions within 10 days in accordance with previously published data. Conclusion: Foreign body reaction might result in delayed leukoencephalopathy, especially following complex endovascular aneurysm treatment. Early high dose followed by low dose ongoing corticosteroid treatment might result in timely remission.