Background We aimed to determine the effects of endovascular coiling of unruptured intracranial aneurysms (UIAs) on cognition to inform treatment decisions. We present the first study using the Montreal Cognitive Assessment (MoCA) to determine neurocognitive changes after endovascular coiling.

Methods We prospectively collected data on all patients with UIAs undergoing endovascular coiling, primary or assisted. Patients completed the MoCA prior to intervention and 1 month and 6 months' post-procedure. A repeated measures linear mixed effects model was used to compare pre-procedure and post-procedure cognition.

Results Thirty-three patients with 33 aneurysms who underwent coiling from April 2017 to May 2020 were included (mean age 55.5, 81.8% female). All procedures used general anesthesia. There was no difference between baseline and post-procedure MoCA scores at any time interval (P>0.05). Mean MoCA scores at baseline, 1 month post-procedure, and 6 months' post-procedure were 25.4, 26.8, and 26.3 respectively. There was also no difference between pre- and post-procedure scores on any individual MoCA domain (visuospatial, naming, memory, attention, language, abstraction, delayed recall, and orientation) at any time interval (P>0.05). Seventeen patients had follow-up MRI or CT imaging, of which 11.8% showed radiographic changes or ischemia. 77.8% of patients with 6-month angiographic follow-up achieved class I, and 22.2% achieved class II Raymond–Roy Occlusion. Thirty-two out of 33 patients had follow-up mRS ≤2.

Conclusion Our study suggests that endovascular coiling does not diminish neurocognitive function. Patients with UIAs in our cohort also had baseline MoCA scores below the cut-off for mild cognitive impairment despite pre-procedure mRS and NIHSS of 0.