COVCOG 2: Cognitive and Memory Deficits in Long COVID: A Second Publication From the COVID and Cognition Study

Abstract

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been often characterized as a respiratory disease. However, it is increasingly being understood as an infection that impacts multiple systems, and many patients report neurological symptoms. Indeed, there is accumulating evidence for neural damage in some individuals, with recent studies suggesting loss of gray matter in multiple regions, particularly in the left hemisphere. There are several mechanisms by which the COVID-19 infection may lead to neurological symptoms and structural and functional changes in the brain, and cognitive problems are one of the most commonly reported symptoms in those experiencing Long COVID – the chronic illness following the COVID-19 infection that affects between 10 and 25% of patients. However, there is yet little research testing cognition in Long COVID. The COVID and Cognition Study is a cross-sectional/longitudinal study aiming to understand cognitive problems in Long COVID. The first paper from the study explored the characteristics of our sample of 181 individuals who had experienced the COVID-19 infection, and 185 who had not, and the factors that predicted ongoing symptoms and self-reported cognitive deficits. In this second paper from the study, we assess this sample on tests of memory, language, and executive function. We hypothesize that performance on “objective” cognitive tests will reflect self-reported cognitive symptoms. We further hypothesize that some symptom profiles may be more predictive of cognitive performance than others, perhaps giving some information about the mechanism. We found a consistent pattern of memory deficits in those that had experienced the COVID-19 infection, with deficits increasing with the severity of self-reported ongoing symptoms. Fatigue/Mixed symptoms during the initial illness and ongoing neurological symptoms were predictive of cognitive performance.

Correlations between Persistent Olfactory and Semantic Memory Disorders after SARS-CoV-2 Infection

“…The fact that generative naming time and T-TODA scores were correlated is in accordance with studies [ 32 , 72 ] that showed olfactory disorders are associated with attentional, memory and executive function disorders. This result is also in line with studies [ 62 , 72 ] suggesting that the severity and persistence of COVID-19 neurological symptoms influence cognitive impairment extent.…”

“…Thus, this study also sought to assess objectively word retrieval ability. A previous study indicated that 59.5% of post COVID-19 patients reported tip-of-the-tongue word finding problems [ 62 ]. However, in our study, word retrieval ability wasn’t impaired.…”

“…This is in line with results found in previous studies, revealing the association of olfactory and cognitive abilities in post COVID-19 patients [ 29 , 71 , 72 ]. In addition, it was also suggested that the more COVID-19 symptoms were more severe and persistent, such as olfactory impairment, the more cognitive impairment was higher [ 29 , 62 , 72 ]. Our results support this observation: the higher were TODA threshold scores, revealing deteriorated olfactory perception, the lower were PPTT scores.…”

Psychological and Cognitive Effects of Long COVID: A Narrative Review Focusing on the Assessment and Rehabilitative Approach

“…Neuropsychological and cognitive symptoms due to Long COVID were evaluated by a complete psychometric battery to assess verbal fluency, nonverbal skills, memory abilities, executive functions, and reasoning [ 84 , 85 , 86 ]. In particular, researchers noticed that both Long COVID patients and healthy participants completed the tasks, but only the “No COVID” group completed a specific cognitive task referred to as the Test of 2D mental rotation, indicating a deficit in reasoning in the Long COVID patients’ group [ 87 ].…”

Neurotropic SARS-CoV-2: Causalities and Realities

“…The reduced sensitivity Neurotropic SARS-CoV-2: Causalities and Realities DOI: http://dx.doi.org/10.5772/intechopen.108573 remained in over 40% of the individuals with olfactory and gustatory impairments and ~23% in those with trigeminal issues [85]. "COVID & Cognition" cross-sectional study continually aims to understand the cognitive deficits in Long COVID [96]. Long COVID comprises long-lasting symptoms and difficulties arising due to COVID-19.…”