Long-Term Cognitive Outcome following Aneurysmal Subarachnoid Haemorrhage

Abstract

Objectives: Survivors of aneurysmal subarachnoid haemorrhage (aSAH) frequently suffer from cognitive dysfunction. The aim of this study was to assess, in a large sample size with long term follow-up, the characteristics of cognitive dysfunction following aSAH and explore whether cognitive deficits mediate employment outcome.

Materials and methods: In this retrospective case-controlled study, aSAH survivors (n = 884) were identified from the UK Biobank and compared to matched controls (n = 3536). Controls were propensity score matched according to age, sex, Townsend deprivation score, educational status and relevant medications known to influence cognition. Cognitive outcomes and employment status were compared between cases and controls using group comparison and cross-tabulation tests. A regression-based mediation analysis was performed to assess whether cognitive deficits mediate employment status following aSAH.

Results: Psychomotor reaction time and employment status significantly differed between aSAH cases and controls with slower reaction times (p < 0.001) and more unemployment or inability to work due to illness (p < 0.001) in the aSAH cohort at a mean follow-up of 125 months. Psychomotor slowing was estimated to mediate a significant proportion (6.59%) of the effect of aSAH on employment status.

Conclusions: Psychomotor reaction time and employment status differed significantly between aSAH cases and control matched individuals in the UK Biobank. Psychomotor slowing following aSAH had a discernible impact on employment status. Psychomotor reaction time and employment status are practical to acquire and can be used as surrogate measures of outcome in future studies of aSAH survivors.

Keywords: Cognition; Employment; Outcome; Subarachnoid haemorrhage.