Neuropsychological Sequelae and Neuroradiological Correlates of Arachnoid Cysts in Adults: A Systematic Review

Background/Objectives: Intracranial arachnoid cysts (Acs) are congenital, usually benign lesions that are frequently regarded as clinically silent in adulthood. Nonetheless, growing evidence indicates that Acs may be associated with subtle but measurable cognitive dysfunction. This systematic review synthesizes neuropsychological and functional neuroimaging findings in adults with intracranial Acs, with a focus on cognitive profiles, functional interactions with the adjacent cortex, and postoperative reversibility. Methods: In accordance with PRISMA 2020 guidelines, MEDLINE/PubMed and Scopus were searched for English-language studies published up to 2023 that reported neuropsychological assessments and/or functional neuroimaging in adult patients with Acs, including single-case reports, case series, and group studies with pre- and post-operative data. Results: Sixty studies met the inclusion criteria. Across anatomical locations, Acs were most consistently associated with impairments in verbal and visual memory and learning, attention, and executive functions, as well as reduced processing or psychomotor speed, whereas language deficits were less consistently observed. Several studies reported postoperative improvement in one or more cognitive domains, suggesting partial reversibility in selected patients. Functional neuroimaging findings revealed altered cortical function in regions adjacent to the cyst, including reduced regional metabolism or cerebral blood flow and task-related activation changes, supporting a functional interaction between Acs and the neighboring cortex. Conclusions: Overall, adults with Acs may exhibit subtle cognitive alterations that vary according to cyst location and appear to be moderated by compensatory mechanisms. These findings underscore the clinical relevance of systematic neuropsychological evaluation and highlight the need for prospective, standardized studies integrating cognitive and neuroimaging outcomes.