The Effect of Mechanical Thrombectomy on the Incidence of Poststroke Cognitive Impairment: A Systematic Review of Inhomogeneous Literature

Introduction: The aim of this study was to evaluate the effect of mechanical thrombectomy (MT) on the incidence of poststroke cognitive impairment (PSCI) in anterior circulation stroke. Methods: Literature research was performed on PubMed/OVID/Cochrane CENTRAL for studies published in 2015-2022. A review of the references of the included papers was performed for further eligible articles. Clinical characteristics, NIHSS, dementia tests, and outcomes were recorded. The exclusion criteria were nonhuman and non-English. Studies qualities were assessed with MINORS/RoB2 and GRADE. A meta-analysis was performed using the standardized mean difference (Cohen's d) to measure effect size. Results: Four studies were included in the systematic review after screening 749 articles. No significant differences were found for age and gender (years: 66.70 ± 11.14 vs. 67.59 ± 10.11, p = 0.37; male 53.8% vs. 56.4%, p = 0.57). MT patients had a more severe stroke than that of the control group (NIHSS: 14.70 ± 4.31 vs. 11.17 ± 4.12; p < 0.0001). The control group consisted of medical therapy-alone patients in all studies. I² was 76.95%, and Q was 43.4%. MT patients have better performance in overall cognition (d = 0.33 [0.074-0.58]) and in several cognitive domains than in the control group (TMT-A, d = 0.37 [0.04-0.70]; TMT-B, d = 0.35 [0.12-0.58]; digit span test [backward], d = 0.61 [0.18-1.06]; colored progressive matrices, d = 0.48 [0.05-0.91]; Stroop test [word reading], d = 0.60 [0.17-1.03]; color naming, d = 0.51 [0.08-0.94]; Rey-Osterrieth Complex Figure [immediate recall], d = 0.79 [0.35-1.23]; Rey Auditory Verbal Learning Test [immediate recall], d = 0.79 [0.36-1.23]; delayed recall, d = 0.46 [0.035-0.89]; and MOCA, d = 0.46 [-0.04 to 0.96]). Medical therapy patients had a higher score in coping strategy than MT patients (COPE-28 acceptance, d = -1.00 [-1.53 to -0.48]). Conclusions: The incidence of PSCI is lower in MT patients than in the control group.