Persistent neurocognitive deficits in cognitively impaired survivors of sepsis are explained by reductions in working memory capacity

Fabian Kattlun; Elizabeth Hertel; Christian Geis; André Scherag; Jonathan Wickel; Kathrin Finke

doi:10.3389/fpsyg.2024.1321145

Persistent neurocognitive deficits in cognitively impaired survivors of sepsis are explained by reductions in working memory capacity

Front Psychol. 2024 Feb 21:15:1321145. doi: 10.3389/fpsyg.2024.1321145. eCollection 2024.

Authors

Fabian Kattlun^{1

2}, Elizabeth Hertel^{1

2}, Christian Geis^{2

3}, André Scherag^{2

4}, Jonathan Wickel^{2

3}, Kathrin Finke^{1

2}

Affiliations

¹ Department of Neurology, Jena University Hospital - Friedrich Schiller University, Jena, Germany.
² Center for Sepsis Control and Care, Jena University Hospital - Friedrich Schiller University, Jena, Germany.
³ Section Translational Neuroimmunology, Department of Neurology, Jena University Hospital - Friedrich Schiller University, Jena, Germany.
⁴ Institute of Medical Statistics, Computer and Data Sciences, Jena University Hospital - Friedrich Schiller University, Jena, Germany.

Abstract

Introduction: Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Mounting evidence suggests that many cognitively impaired sepsis survivors show long-term neurocognitive deficits in neuropsychological tasks. To date, the underlying mechanisms of these deficits are insufficiently understood. Based on previous evaluations we hypothesized that visual attention and working memory may be affected in a sample of cognitively impaired sepsis survivors.

Methods: We utilized psychophysical whole-and partial-report paradigms based on the computational theory of visual attention (TVA) to determine (i) whether sepsis survivors show changes in basic parameters of visual attention and working memory, (ii) whether the affected parameters are related to neuropsychological test results in a standard battery in sepsis survivors and matched healthy control participants, (iii) whether between-group differences in these basic parameters of visual attention could account for underperformance of sepsis survivors in neuropsychological tests when adjusting for potentially relevant clinical variables.

Results: We showed that, in sepsis survivors, the maximum number of elements consciously maintained in an instant, i.e. the working memory storage capacity K, is reduced (sepsis survivors: M = 3.0; healthy controls: M = 3.4). Moreover, K explained variance in neurocognitive outcomes -17% in attentional and 16 % in executive functions - in a standard neuropsychological battery. The association remained stable when adjusting for clinical variables.

Discussion: Thus, in our sample of cognitively impaired sepsis survivors, a reduction in working memory capacity seems to be a critical determinant of the neurocognitive sequelae. It should be the subject of future work on mechanisms but may also serve as surrogate outcome measure in interventional studies.

Keywords: cognition; neuropsychological impairment; sepsis; visual attention; working memory.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the Federal Ministry of Education and Research (BMBF), Germany, FKZ 01EO1502, by funds of the German Forschungsgemeinschaft (DFG) to KF, FI 1424/2 – 2, and by funds of the Schilling-Foundation to CG.