Trajectory of post-COVID brain fog, memory loss, and concentration loss in previously hospitalized COVID-19 survivors: the LONG-COVID-EXP multicenter study

César Fernández-de-Las-Peñas; Ignacio Cancela-Cilleruelo; Jorge Rodríguez-Jiménez; José A Arias-Navalón; José D Martín-Guerrero; Oscar J Pellicer-Valero; Lars Arendt-Nielsen; Margarita Cigarán-Méndez

doi:10.3389/fnhum.2023.1259660

Trajectory of post-COVID brain fog, memory loss, and concentration loss in previously hospitalized COVID-19 survivors: the LONG-COVID-EXP multicenter study

Front Hum Neurosci. 2023 Nov 9:17:1259660. doi: 10.3389/fnhum.2023.1259660. eCollection 2023.

Affiliations

¹ Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation, Universidad Rey Juan Carlos (URJC), Madrid, Spain.
² Center for Neuroplasticity and Pain, Department of Health Science and Technology, School of Medicine, Aalborg University, Aalborg, Denmark.
³ School of Medicine, Universidad CEU-San Pablo, Madrid, Spain.
⁴ Intelligent Data Analysis Laboratory, Department of Electronic Engineering, ETSE (Engineering School), Universitat de València (UV), Valencia, Spain.
⁵ Valencian Graduate School and Research Network of Artificial Intelligence (ValgrAI), València, Spain.
⁶ Image Processing Laboratory (IPL), Universitat de València, Parc Científic, Paterna, València, Spain.
⁷ Department of Gastroenterology & Hepatology, Mech-Sense, Clinical Institute, Aalborg University Hospital, Aalborg, Denmark.
⁸ Steno Diabetes Center North Denmark, Clinical Institute, Aalborg University Hospital, Aalborg, Denmark.
⁹ Department of Psychology, Universidad Rey Juan Carlos (URJC), Madrid, Spain.

Abstract

Objective: This study aimed to apply Sankey plots and exponential bar plots for visualizing the trajectory of post-COVID brain fog, memory loss, and concentration loss in a cohort of previously hospitalized COVID-19 survivors.

Methods: A sample of 1,266 previously hospitalized patients due to COVID-19 during the first wave of the pandemic were assessed at 8.4 (T1), 13.2 (T2), and 18.3 (T3) months after hospital discharge. They were asked about the presence of the following self-reported cognitive symptoms: brain fog (defined as self-perception of sluggish or fuzzy thinking), memory loss (defined as self-perception of unusual forgetfulness), and concentration loss (defined as self-perception of not being able to maintain attention). We asked about symptoms that individuals had not experienced previously, and they attributed them to the acute infection. Clinical and hospitalization data were collected from hospital medical records.

Results: The Sankey plots revealed that the prevalence of post-COVID brain fog was 8.37% (n = 106) at T1, 4.7% (n = 60) at T2, and 5.1% (n = 65) at T3, whereas the prevalence of post-COVID memory loss was 14.9% (n = 189) at T1, 11.4% (n = 145) at T2, and 12.12% (n = 154) at T3. Finally, the prevalence of post-COVID concentration loss decreased from 6.86% (n = 87) at T1, to 4.78% (n = 60) at T2, and to 2.63% (n = 33) at T3. The recovery exponential curves show a decreasing trend, indicating that these post-COVID cognitive symptoms recovered in the following years after discharge. The regression models did not reveal any medical record data associated with post-COVID brain fog, memory loss, or concentration loss in the long term.

Conclusion: The use of Sankey plots shows a fluctuating evolution of post-COVID brain fog, memory loss, or concentration loss during the first years after the infection. In addition, exponential bar plots revealed a decrease in the prevalence of these symptoms during the first years after hospital discharge. No risk factors were identified in this cohort.

Keywords: COVID-19; Sankey plots; brain fog; concentration; memory loss.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The LONG-COVID-EXP-CM is supported by a grant associated to the Fondo Europeo De Desarrollo Regional -Recursos REACT-UE del Programa Operativo de Madrid 2014-2020, en la línea de actuación de proyectos de I+D+i en materia de respuesta a COVID 19. An independent research grant was received from Novo Nordisk Foundation (NNF21OC0067235) (lncidence and Characterization of Persistent Pain in COVID-19 Survivors: A Pan-European Concerted Action). None of the sponsor had no role in the design, collection, management, analysis, or interpretation of the data, draft, review, or approval of the manuscript or its content. The authors were responsible for the decision to submit the manuscript for publication, and the sponsor did not participate in this decision.