A meta-analysis of executive functions among survivors of subarachnoid haemorrhage.

Subarachnoid Haemorrhage (SAH) is a type of stroke which is suggested to result in Executive Functioning (EF) deficits. Within the SAH research, EF is typically assessed as a unitary cognitive construct. Therefore, the nature and extent to which the different components of EF are impacted post SAH remain unclear. In this meta-analysis, 10 studies met selection criteria including 248 SAH participants, treated by endovascular coiling. Participants were assessed by EF measures and compared with 230 controls. Searches were conducted in November 2018 including Medline, PsychINFO, Web of Science, Scopus and CINAHL databases. EF measures were assigned to categories including Cognitive Flexibility, Working Memory, Inhibitory Control and Planning/Problem Solving [Diamond, 2013. Executive functions. Annual Review of Psychology, 64(1), 135-168. https://doi.org/10.1146/annurev-psych-113011-143750]. A statistically significant effect was found for overall EF. Cognitive Flexibility (G = -0.76) and Inhibitory Control (G = -0.51) generated moderate effect sizes, while Working Memory and Planning/Problem Solving found a small effect size (G = -0.45 and G = -0.49, respectively). The I2 statistic suggested small to moderate heterogeneity between studies, hypothesized to relate to different cognitive tools. Underlying components of EF appear to be differentially impacted post SAH, with Cognitive flexibility demonstrating the largest degree of deficit. Recommendations for a standardized and uniform assessment of EF post SAH are outlined.