Cognitive outcomes after unruptured intracranial aneurysm treatment with flow diversion

Objective: Flow diversion is increasingly used to treat a variety of intracranial aneurysms with good safety and efficacy; however, there is some evidence that this treatment is associated with a larger postoperative ischemic burden on imaging than that with other traditional endovascular modalities. These findings typically do not manifest as neurological deficits, but any subtle effects on cognition remain unknown. In this study, the authors describe the neurocognitive performance of a cohort of patients with unruptured intracranial aneurysms (UIAs) before and after treatment with flow diversion. This is the first report of cognitive outcomes following aneurysm treatment with flow diversion.

Methods: The authors prospectively collected data on cognitive function using the Montreal Cognitive Assessment (MoCA) tool in patients with UIAs who were undergoing endovascular aneurysm treatment with flow diversion between June 2017 and July 2019. Patients completed the MoCA prior to intervention, at the 1-month follow-up after treatment, and again at 6 months after the procedure. All patients with UIAs treated with flow diversion were included regardless of age, aneurysm location, or morphology, unless their functional status precluded completion of the MoCA instrument. A repeated-measures linear mixed-effects model was used to compare preintervention and postintervention cognitive status at the time intervals outlined.

Results: Fifty-one patients with 61 aneurysms underwent endovascular aneurysm treatment with flow diversion (mean age 52.5 years, 90.2% females). There was no difference between baseline and postprocedure MoCA scores at any time interval (p > 0.05). The MoCA scores at baseline, 1 month postprocedure, and 6 months postprocedure were 26.1, 26.2, and 26.6, respectively. There was also no difference between pre- and postprocedure scores on any individual domain of the instrument (visuospatial, naming, attention, language, abstraction, delayed recall, and orientation) at any time interval (p > 0.05). Thirty-four patients had follow-up MRI or CT imaging, 5 of whom showed radiographic changes or ischemia. All patients with follow-up clinical evaluation had a 6-month modified Rankin Scale score ≤ 2.

Conclusions: Flow diversion is increasingly used in the treatment of intracranial aneurysms. This study suggests that this treatment may not alter neurocognitive function. Larger patient samples and longer follow-ups with other tests of cognitive functions are needed to confirm these findings.