Interhemispheric arachnoid cysts: case series

Abstract

Objective: Interhemispheric arachnoid cysts (IHACs) are a rare congenital malformation arising from the duplication of the arachnoid membrane of the cerebral meninges associated with malformations of the corpus callosum. The scope of this study is to describe a series of cases of IHACs treated via neuroendoscopy in a reference center. Method: description of a case series of children diagnosed with IHAC undergoing neuroendoscopic treatment (cystoventriculostomy) between 2015 and 2022, describing the main clinical manifestations, the surgical indication, and the neuroendoscopic technique performed. Results: Four children diagnosed with IHACs, with a predominance of males (3:1), were included in the study. Considering the Mori and Barkovich classification systems, magnetic resonance imaging of the brain showed multiseptate extra-axial interhemispheric cysts without communication with the ventricular system in all cases. Macrocrania and bulging fontanel were the clinical manifestations that indicated urgent hospitalization for the proposed neurosurgical treatment. Conclusion: Signs of increased intracranial pressure were observed in all cases of IHACs in the first months of life. Endoscopic cystoventriculostomy was performed in all cases with satisfactory results, showing that this is an option to be evaluated for the treatment of IHACs classified as multiseptate extra-axial and without communication with the ventricular system or brain cisterns, according to Mori and Barkovich classification systems.