Cognitive improvement following endovascular embolization in patients with intracranial dural arteriovenous fistula: The Neuropsychology in dural ArterIal Fistula (NAIF) Study.

Background: Cognitive improvement after endovascular embolization of an intracranial dural arteriovenous fistula (dAVF) remains unexplored. We aim to investigate cognitive changes following endovascular embolization of dAVFs.

Methods: Neuropsychology in dural ArterIal Fistula (NAIF) was a prospective multicentric study including patients with an angiographic diagnosis of dAVF who underwent endovascular embolization over the course of 4 years. A complete neuropsychological evaluation comprising five cognitive domains (attention and executive functions, memory, language, praxis, gnosis) was performed at baseline and 3 months follow-up. Mean Z scores for cognitive tests were compared pre- and post-treatment using paired sample t-tests, where higher Z scores indicate better cognition. Effect sizes were computed as Cohen's d.

Results: A total of 32 patients (mean age 61.1±15.4 years, 10 (31.3%) females) were included. Patients exhibited improved performance in attention and executive functions: executive functions-attention (+0.282, P=0.009, d=0.29), executive functions-fluencies (+0.283, P=0.029, d=0.4), and executive functions-processing speed (+0.471, P=0.039, d=0.41). There was an increase in memory: verbal learning and verbal delayed recall scores (+0.513, P<0.001, d=0.55, and +0.385, P=0.001, d=0.41, respectively), while verbal recognition parameters (+0.839, P=0.086, d=0.37) and visual memory (delayed recall) (+0.430, P=0.060, d=0.35) displayed trends toward improved performance. Regarding language, there was significant overall improvement (+0.300, P=0.014, d=0.24), but neither praxis nor gnosis changed significantly. These cognitive outcomes were independent of the severity (measured as Cognard classification), and no patient experienced cognitive worsening.

Conclusion: This study suggests that endovascular embolization confers cognitive benefits on dAVF patients undergoing endovascular embolization and may be beneficial even for patients with a low risk of hemorrhage.