Content area
Full Text
Brain fog is a lay term that has been used to describe a subjective experience of difficulties with word finding, concentration, and memory. Tsokos (2021) describes it as a subclinical form of cognitive disorder that can impair or slow down perception, processing, learning, storage, and expression. By impairing short-term storage (i.e., working memory) and executive functions (e.g., planning, organizing, decision making), it can make multi-tasking difficult. Brain fog is often accompanied by extreme fatigue and a general feeling of being overwhelmed (Stang, 2021). Persistent or recurrent brain fog is a commonly described phenomenon associated with long intensive care unit (ICU) stays (that generally include some degree of social isolation and immobility), chemotherapy, autoimmune disorders, traumatic brain injuries, and post-acute infectious processes. Brain fog is described as one of the more debilitating persistent conditions and is often associated with depressive and anxiety symptoms. The purpose of this article is to review current literature to better understand the contributing factors and to look for evidence-based approaches to treatment.
Post-Acute Infection and Brain Fog
Persistent brain fog, fatigue, and psychiatric problems are post-recovery symptoms of coronavirus disease 2019 (COVID-19; aka long COVID syndrome, long haul COVID) (Collins, 2021). Several large studies have researched the long-term outcomes of persons who had confirmed COVID-19 infections. Havervall et al. (2021) reported that, at 8 months post-infection, 15% of people reported at least one moderate to severe persistent symptom (fatigue was one of the most common complaints) and 11% reported continued marked disruption in work, home, or family life. Other researchers reported the incidence of mood or anxiety disorders to be 23% to 24% at 6 months (Huang, Huang, et al., 2021; Taquet et al., 2021) and 26% at 12 months (Huang, Yao, et al., 2021). Although self-report of brain fog is common after COVID-19 recovery, a study by Zhou et al. (2020) identified measurable impairments in sustained attention post-COVID recovery that correlated with inflammatory markers.
There seems to be general agreement among researchers that post-acute infection brain fog and fatigue are related to immune system–mediated neuroinflammation. When the immune system recognizes viruses, bacteria, or other infectious agents, it triggers a protective response involving the accumulation of...