Association between olfactory dysfunction and mood disturbances with objective and subjective cognitive deficits in long-COVID

Sensing Sociality: Disruptions of Social Life When Living With Chemosensory Dysfunctions After COVID-19

Taste and smell are of direct importance in most social interactions. Radical disruptions in these senses can, therefore, substantially disrupt sociality. This paper focuses on the experiences of a particular type of disruption: persistent chemosensory dysfunctions after COVID-19. We conducted semi-structured interviews with 30 patients undergoing treatment for chemosensory dysfunctions and analyzed the ways in which their experiences have influenced social relations and activities, particularly regarding food and eating. The findings reveal that these dysfunctions have made the participants markedly aware that food and eating are pivotal to full participation in social life. As is smell, both surrounding smells and the perception of one's own smell, with dysfunctions leading to several social consequences. Such problems are handled through both avoidance behavior and adaptations. While adaptations facilitate interactions, they come at the cost of feeling a burden to others or not fully appreciating an event (e.g., a shared meal). Social support is of great importance, ranging from minor practical assistance, such as a friend checking if the milk is sour, to the profound emotional relief felt from empathic treatment and recognition that the problems are real. Here, healthcare professionals can play a vital role, even in the (perceived) absence of clinical effectiveness of the treatment. The experiences expressed are partially in line with other manifestations of Long COVID and with chemosensory dysfunctions due to other illnesses, but only partially, since this is a patient group with needs and experiences that are unique, in that sociality is so strongly affected solely by disruptions in sensory abilities.

Correlation Between COVID-19 Recovery, Executive Function Decline, and Emotional State

Objective

The aim of this study was to determine whether there is a relationship between the time since recovery from coronavirus disease 2019 (COVID-19) and alterations in executive functions. We also evaluate the emotional state of post-COVID-19 patients.

Patients and Methods

We assessed patients between 18 and 50 years old, who had a history of COVID-19 with mild, moderate, or severe illness. We used the Batería Neuropsicológica de Funciones Ejecutivas y Lóbulos Frontales-3 (BANFE-3), Mini-Mental State Examination (MMSE), and Mini-International Neuropsychiatric Interview (MINI), in addition to a semi-structured interview. Spearman's correlation coefficient was used, with a p value <0.05 indicating significance.

Results

We evaluated 67 patients with a mean age of 34.6±9.6 years, most of whom had ≥13 years of schooling (n=55, 82.1%). Among them, 52 (77.6%) reported persistent symptoms after resolution of the condition, with fatigue being the most frequent (n=20, 29.9%). Most participants had an adequate score on the MMSE (n=60, 89.6%). However, 19 (28.4%) showed alterations in the BANFE-3 total score, with mental flexibility as the most affected function (n=25, 37.3%). In participants from the first COVID-19 wave, a negative correlation was observed between the standardized orbitofrontal area scores and the time since recovery from the infection (r=-0.841, p=0.016), suggesting a pattern of deterioration over time, mainly in stimulus inhibition (r=0.880, p=0.021). Regarding emotional state, 45 subjects (67.2%) exhibited emotional alterations, with anxiety symptoms being the most frequent (n=33, 49.3%). Furthermore, individuals with depressive symptoms (n=32, 47.8%) were more likely to experience executive function impairment after COVID-19 (ExpB 0.302, 95% CI 0.098-0.933, p=0.038).

Conclusion

COVID-19 could lead to alterations in executive functions, probably resulting from progressive damage to orbitofrontal area functions, mainly in stimulus inhibition. However, the generalizability of these findings is limited, highlighting the need for further research with robust methodology. Furthermore, depression appears to be an indicator of cognitive impairment in individuals recovering from COVID-19. Therefore, cognitive rehabilitation and psychological support are essential for patients affected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection.

How Are Brain Fog Symptoms Related to Diet, Sleep, Mood and Gastrointestinal Health? A Cross-Sectional Study

Background and Objectives: Brain fog, characterized by cognitive difficulties such as memory impairment, lack of focus, and mental fatigue, is a common symptom reported during recovery from COVID-19, particularly in long COVID cases. This study explores potential triggers such as sleep quality, mood, and gastrointestinal health and examines the link between adherence to the MIND diet and brain fog severity. Materials and Methods: A cross-sectional study was conducted between 1 July and 15 December 2022. The questionnaire assessed brain fog symptoms, dietary habits, sleep quality, mood, and gastrointestinal symptoms. Linear regression analysis examined the relationships between brain fog symptoms, demographic factors, sleep quality, MIND diet adherence, and gastrointestinal symptoms. Results: Brain Fog Scale (BFS) scores were significantly higher in individuals who had COVID-19 (p < 0.05) and even higher in those with reinfection. Women had higher BFS and Brain Fog Severity Score (BFSS), MIND Diet, The Gastrointestinal Symptom Rating Scale (GSRS), Brief Mood Introspection Scale (BMIS) Pleasant-Unpleasant scores (p < 0.05). BFS and BFSS were positively correlated with GSRS (p < 0.05), while no correlation was found with MIND diet adherence. A negative correlation was observed between BFS and Sleep Quality Scale (SQS) (p < 0.05), but this was not significant in regression (p = 0.367). GSRS, Pleasant-Unpleasant Dimension, and Arousal-Calm Dimension were significant predictors of BFS (R = 0.599, R2 = 0.358, p < 0.01). Conclusions: This study identifies being female as a risk factor for brain fog symptoms, with women reporting higher BFS and BFSS scores. While sleep quality showed a negative correlation with brain fog symptoms, this relationship was not significant in the regression model, suggesting that other factors, such as mood and gastrointestinal symptoms, may play a more dominant role. However, adherence to the MIND diet showed no significant relationship with brain fog symptoms. These findings suggest that addressing mood and gastrointestinal health may be key to managing brain fog in long COVID.

Age-dependent phenotypes of cognitive impairment as sequelae of SARS-CoV-2 infection

Cognitive changes associated with PASC may not be uniform across populations. We conducted individual-level pooled analyses and meta-analyses of cognitive assessments from eight prospective cohorts, comprising 2,105 patients and 1,432 controls from Argentina, Canada, Chile, Greece, India, Italy, Russia, and the UK. The meta-analysis found no differences by country of origin. The profile and severity of cognitive impairment varied by age, with mild attentional impairment observed in young and middle-aged adults, but memory, language, and executive function impairment in older adults. The risk of moderate to severe impairment doubled in older adults. Moderately severe or severe impairment was significantly associated with infection diagnoses (chi-square = 26.57, p ≤ 0.0001) and the severity of anosmia (chi-square = 31.81, p ≤ 0.0001). We found distinct age-related phenotypes of cognitive impairment in patients recovering from COVID-19. We identified the severity of acute illness and the presence of olfactory dysfunction as the primary predictors of dementia-like impairment in older adults.

Trajectories of Coping With Persistent Smell and Taste Dysfunction After a Covid-19 Infection-A Qualitative Interview Study

AIM

To explore trajectories of understanding and managing persistent chemosensory dysfunction after COVID-19 in patients undergoing clinical treatment.

DESIGN

A descriptive qualitative interview study with a realist approach.

METHOD

Data were collected in Sweden, from August 2022 to March 2023 through semi-structured interviews with 30 patients undergoing treatment for long-lasting smell and taste dysfunction resulting from COVID-19. Thematic analysis was applied in a process that involved continuous discussions and refinement of codes into themes and subthemes.

RESULTS

Three main themes were identified: (1) Understanding the sensory alterations, which includes subthemes of Searching for validation and Seeking remedies; (2) Practical coping strategies, encompassing Adapted eating and Managing olfactory training and (3) Navigating the emotional landscape, featuring Self-persuasion and suppression and The ambivalence of acceptance. These themes highlight the cyclic and fluid nature of coping with the dysfunction, reflecting a dynamic process of adaptation. Despite treatment options like olfactory training, participants frequently experienced frustration due to limited perceived improvement and the psychological toll of managing their condition.

CONCLUSION

The study highlights the complex and personal nature of coping with long-term smell and taste dysfunction post-COVID-19. Coping strategies varied widely and evolved over time, reflecting a dynamic process of adaptation. The emotional and psychological impact was profound, underscoring the need for comprehensive treatment approaches that include both physiological and psychological support. There is a need for more effective interventions and support mechanisms to improve the quality of life for those affected by these persistent symptoms.

IMPLICATIONS

This study contributes to the understanding of COVID-19's long-term effects on smell and taste, highlighting the need for ongoing support from health care, further research into effective interventions, and a comprehensive approach to care for individuals affected by these conditions.

IMPACT

This study addresses trajectories and challenges of coping with persistent chemosensory dysfunction. Findings emphasise the complexity of managing persistent chemosensory dysfunction and the critical role of personalised care. The study contributes to knowledge for nurses in understanding patients with chemosensory dysfunction.

REPORTING METHOD

This research adheres to the EQUATOR guidelines: Standards for reporting qualitative research (SRQR).

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

Knowledge, Attitudes, and Practices Among Community Populations Toward Long COVID in China

Purpose

This study aimed to assess the knowledge, attitudes and practices (KAP) among community populations toward Long COVID.

Patients and Methods

This cross-sectional study was conducted between March 2023 and June 2023 at the Ordos Mongolian hospital and Ordos Central Hospital in Ordos, Inner Mongolia, China, employing a self-designed questionnaire to collect demographic data from community populations and evaluate their knowledge, attitudes, and practices toward Long COVID.

Results

A total of 591 participants were enrolled in this study. Among them, 343 (58.04%) were female and 317 (53.64%) aged 40 to 59 years. The mean knowledge, attitudes and practices scores were 6.02±1.19 (possible range: 0-7), 26.83±2.96 (possible range: 7-35), and 45.91±7.20 (possible range: 11-55), respectively. The Pearson's correlation analysis indicated significant positive correlations between knowledge and attitudes (r=0.210, P<0.001), and attitudes and practices (r=0.476, P<0.001). The structural equation model demonstrated that knowledge positively affect attitudes, as indicated by a path coefficient of 1.028 (P<0.001), and attitudes positively affect practices, with a path coefficient of 0.817 (P<0.001).

Conclusion

Although our findings indicate that community populations generally have adequate knowledge, active attitudes, and proactive practices regarding Long COVID, there is still a need for healthcare providers to further enhance Long COVID awareness in the community. This involves fostering positive attitudes through open communication, emphasizing the importance of early intervention and treatment adherence, and encouraging continued adherence to preventive measures.

Patients recovering from COVID-19 who presented with anosmia during their acute episode have behavioral, functional, and structural brain alterations

Patients recovering from COVID-19 commonly exhibit cognitive and brain alterations, yet the specific neuropathological mechanisms and risk factors underlying these alterations remain elusive. Given the significant global incidence of COVID-19, identifying factors that can distinguish individuals at risk of developing brain alterations is crucial for prioritizing follow-up care. Here, we report findings from a sample of patients consisting of 73 adults with a mild to moderate SARS-CoV-2 infection without signs of respiratory failure and 27 with infections attributed to other agents and no history of COVID-19. The participants underwent cognitive screening, a decision-making task, and MRI evaluations. We assessed for the presence of anosmia and the requirement for hospitalization. Groups did not differ in age or cognitive performance. Patients who presented with anosmia exhibited more impulsive alternative changes after a shift in probabilities (r =  - 0.26, p = 0.001), while patients who required hospitalization showed more perseverative choices (r = 0.25, p = 0.003). Anosmia correlated with brain measures, including decreased functional activity during the decision-making task, thinning of cortical thickness in parietal regions, and loss of white matter integrity. Hence, anosmia could be a factor to be considered when identifying at-risk populations for follow-up.

An immersive virtual reality-based object-location memory task reveals spatial long-term memory alterations in Long-COVID

Object-location memory (OLM) is a type of declarative memory for spatial information and consists of the individual's ability to establish accurate associations between objects and their spatial locations. Long-COVID describes the long-term effects of the COVID-19 disease. Long-COVID patients show medial temporal lobe dysfunction and neuropsychological alterations affecting memory. This study aimed to assess OLM in a group of Long-COVID patients, n=66, and a Control group of healthy individuals with similar age and sex composition, n=21, using an immersive virtual reality (iVR)-based OLM task. We also explored associations between the performance in the iVR-based OLM task and general cognitive function (MoCA), and both verbal (VSTM) and visuospatial (SSTM) span. The Long-COVID group showed fewer correct responses, made more task attempts, and invested more time in the iVR-based OLM task than the Control group. Delayed memory was more severely altered than immediate memory in Long-COVID participants. Better MoCA scores of the Long-COVID group were strongly associated with shorter times to complete the immediate recall of the iVR-based OLM task. Besides, the months elapsed since the COVID-19 infection were slightly associated with fewer correct responses in the immediate and 24-hour recalls. These results corroborate previous findings of memory alterations in the Long-COVID syndrome using an iVR-based OLM task, adding new evidence on spatial memory and long-term memory in this population. Implementing spatial iVR tasks to clinical research may improve our understanding of neuropsychological disorders.

Understanding the olfactory role in post-COVID cognitive and neuropsychiatric manifestations

Introduction

Olfactory dysfunction (OD) is frequent after SARS-CoV-2 infection. The aim of this study was to examine if long-term OD is common in post-COVID condition, and the relationship between olfaction, cognition, neuropsychiatric symptoms, and disease duration in these patients.

Methods

This study included 121 participants with post-COVID condition and 51 healthy controls (HC). A comprehensive neuropsychological and neuropsychiatric assessment was conducted, encompassing various domains, including general cognition, processing speed, verbal fluency, attention, verbal memory, visual memory, visuoconstructive ability, visuospatial ability, abstraction, executive functions, anxious-depressive symptoms, general health perception, fatigue level, sleep quality, and olfaction. Statistical analyses were carried out to understand the relationship of OD with cognition, and its role as moderator variable.

Results

In total, 25% of the post-covid patients had a reduced smell capacity, while only 9.3% of HC presented OD. Post-COVID patients had statistically significantly worse cognitive performance and clinical status than HC. Verbal fluency (AUC = 0.85, p < 0.001), and attention (AUC = 0.82, p < 0.001) were the variables that best discriminate between groups. OD seemed to be a moderator between fatigue and cognition, and between disease duration and attention (β = -0.04; p = 0.014).

Discussion

The study highlights marked cognitive and neuropsychiatric sequelae in individuals post-COVID relative to HC. Olfactory impairment exhibits correlations with both cognitive performance and general health. Olfaction emerges as a potential prognostic marker owing to its moderating influence on disease severity indicators.

Type I interferon signaling, cognition and neurodegeneration following COVID-19: update on a mechanistic pathogenetic model with implications for Alzheimer's disease

COVID-19's effects on the human brain reveal a multifactorial impact on cognition and the potential to inflict lasting neuronal damage. Type I interferon signaling, a pathway that represents our defense against pathogens, is primarily affected by COVID-19. Type I interferon signaling, however, is known to mediate cognitive dysfunction upon its dysregulation following synaptopathy, microgliosis and neuronal damage. In previous studies, we proposed a model of outside-in dysregulation of tonic IFN-I signaling in the brain following a COVID-19. This disruption would be mediated by the crosstalk between central and peripheral immunity, and could potentially establish feed-forward IFN-I dysregulation leading to neuroinflammation and potentially, neurodegeneration. We proposed that for the CNS, the second-order mediators would be intrinsic disease-associated molecular patterns (DAMPs) such as proteopathic seeds, without the requirement of neuroinvasion to sustain inflammation. Selective vulnerability of neurogenesis sites to IFN-I dysregulation would then lead to clinical manifestations such as anosmia and cognitive impairment. Since the inception of our model at the beginning of the pandemic, a growing body of studies has provided further evidence for the effects of SARS-CoV-2 infection on the human CNS and cognition. Several preclinical and clinical studies have displayed IFN-I dysregulation and tauopathy in gene expression and neuropathological data in new cases, correspondingly. Furthermore, neurodegeneration identified with a predilection for the extended olfactory network furthermore supports the neuroanatomical concept of our model, and its independence from fulminant neuroinvasion and encephalitis as a cause of CNS damage. In this perspective, we summarize the data on IFN-I as a plausible mechanism of cognitive impairment in this setting, and its potential contribution to Alzheimer's disease and its interplay with COVID-19.

Olfactory deficit: a potential functional marker across the Alzheimer's disease continuum

Alzheimer's disease (AD) is a prevalent form of dementia that affects an estimated 32 million individuals globally. Identifying early indicators is vital for screening at-risk populations and implementing timely interventions. At present, there is an urgent need for early and sensitive biomarkers to screen individuals at risk of AD. Among all sensory biomarkers, olfaction is currently one of the most promising indicators for AD. Olfactory dysfunction signifies a decline in the ability to detect, identify, or remember odors. Within the spectrum of AD, impairment in olfactory identification precedes detectable cognitive impairments, including mild cognitive impairment (MCI) and even the stage of subjective cognitive decline (SCD), by several years. Olfactory impairment is closely linked to the clinical symptoms and neuropathological biomarkers of AD, accompanied by significant structural and functional abnormalities in the brain. Olfactory behavior examination can subjectively evaluate the abilities of olfactory identification, threshold, and discrimination. Olfactory functional magnetic resonance imaging (fMRI) can provide a relatively objective assessment of olfactory capabilities, with the potential to become a promising tool for exploring the neural mechanisms of olfactory damage in AD. Here, we provide a timely review of recent literature on the characteristics, neuropathology, and examination of olfactory dysfunction in the AD continuum. We focus on the early changes in olfactory indicators detected by behavioral and fMRI assessments and discuss the potential of these techniques in MCI and preclinical AD. Despite the challenges and limitations of existing research, olfactory dysfunction has demonstrated its value in assessing neurodegenerative diseases and may serve as an early indicator of AD in the future.

A Comprehensive Review of COVID-19-Related Olfactory Deficiency: Unraveling Associations with Neurocognitive Disorders and Magnetic Resonance Imaging Findings

Olfactory dysfunction (OD) is one of the most common symptoms in COVID-19 patients and can impact patients' lives significantly. The aim of this review was to investigate the multifaceted impact of COVID-19 on the olfactory system and to provide an overview of magnetic resonance (MRI) findings and neurocognitive disorders in patients with COVID-19-related OD. Extensive searches were conducted across PubMed, Scopus, and Google Scholar until 5 December 2023. The included articles were 12 observational studies and 1 case report that assess structural changes in olfactory structures, highlighted through MRI, and 10 studies correlating the loss of smell with neurocognitive disorders or mood disorders in COVID-19 patients. MRI findings consistently indicate volumetric abnormalities, altered signal intensity of olfactory bulbs (OBs), and anomalies in the olfactory cortex among COVID-19 patients with persistent OD. The correlation between OD and neurocognitive deficits reveals associations with cognitive impairment, memory deficits, and persistent depressive symptoms. Treatment approaches, including olfactory training and pharmacological interventions, are discussed, emphasizing the need for sustained therapeutic interventions. This review points out several limitations in the current literature while exploring the intricate effects of COVID-19 on OD and its connection to cognitive deficits and mood disorders. The lack of objective olfactory measurements in some studies and potential validity issues in self-reports emphasize the need for cautious interpretation. Our research highlights the critical need for extensive studies with larger samples, proper controls, and objective measurements to deepen our understanding of COVID-19's long-term effects on neurological and olfactory dysfunctions.

Cognitive impairment after recovery from COVID-19: Frequency, profile, and relationships with clinical and laboratory indices

Cognitive impairment (CI) is regarded as a remarkable burden in COVID-19 survivors. Its prevalence and profile, and relationships with the disease clinical and laboratory indices, remain unclear. The present study investigated, in a large sample of patients recovered from COVID-19, the frequency of CI with both a face-to-face screening tool and comprehensive test battery (MCCB). The study also evaluated the profile of CI and its relationships with COVID-19 clinical and laboratory indices and with psychopathological features. Out of 1344 subjects assessed for eligibility, 736 completed the screening phase 11 months after the COVID-19 infection; 402 participated in the baseline phase and completed an in depth cognitive, clinical and laboratory assessment about one month later. More than one third of the screened subjects presented a CI (COG+); it was associated to age, education, male gender, COVID-19 severity, and presence of anosmia, dyspnea at rest and exertional dyspnea during the acute phase. COG+ subjects showed a higher severity of depression, anxiety and post-traumatic distress, and worse global functioning, than subjects without CI. The MCCB showed that 45% of the subjects had a CI involving attention, working memory, verbal learning, visual learning, and reasoning and problem solving. Finally, neurocognitive functioning was inversely correlated with LDH blood levels, a potential biomarker of disease severity. According to our findings, cognitive functioning should be routinely and periodically assessed in COVID-19 patients, especially in older subjects, who experienced more severe COVID-19 symptoms. In case of persisting dysfunctions cognitive training programs should be considered as treatment strategies.

Olfactory Epithelium Infection by SARS-CoV-2: Possible Neuroinflammatory Consequences of COVID-19

BACKGROUND

The loss of smell is a typical diagnostic symptom of coronavirus disease 2019 (COVID-19). This sensorial deprivation may be expressed as quantitative (anosmia or hyposmia) or qualitative (dysosmia) alterations as a consequence of anatomical disturbances of the nasal epithelium structure. The olfactory system sends direct neuronal connections to brain structures that are involved in emotional processing, including deep temporal nuclei. This anatomical and functional feature may be related to the occurrence of emotional disorders among COVID-19 patients.

SUMMARY

We identify a possible sequence of events, from typical olfactory dysfunction that is associated with COVID-19 and caused by olfactory epithelium damage to disturbances in the quality of life and emotional state of infected patients that is attributable to possible neuroinflammatory processes. Sensorial deprivation causes deleterious actions on mood, negatively affecting quality of life. Olfactory dysfunction that is associated with COVID-19 occurs concurrently with psychological distress, symptoms of anxiety, and depressive disorders and impinges on self-perceived quality of life.

KEY MESSAGES

Changes in mood are certainly associated with multiple factors, including the environment and isolation, but the observation that the virus may penetrate the central nervous system through the olfactory bulb and the connection between the olfactory system and prefrontal and orbitofrontal cortices and the amygdala-hippocampus do not allow one to discard neural factors that are involved in the pathophysiology of emotional symptoms in post-COVID-19 patients. Behavioral symptoms of COVID-19 involve local olfactory actions and the participation of central neuronal systems.

The Hidden Impact of Covid-19 on Memory: Disclosing Subjective Complaints

Objective

A significant body of research has suggested that the contraction of SARS-CoV-2 may cause memory impairment, even in the months following recovery. In this regard, studies suggest that COVID-19 predominantly targets structures and cortices within the temporal lobe, and the hippocampus, a critical brain structure for memory and spatial navigation.The purpose of this study was to investigate the potential impact of the COVID-19 pandemic on subjective memory complaints, which represent an individual's perception of subtle changes in memory in the absence of an objective memory impairment.

Method

to explore how the COVID-19 pandemic may affect subjective memory complaints, we incorporated ad hoc self-reported measures of subjective memory complaints, the "Subjective Memory Complaints Questionnaire" (SMCQ) and the "Prospective and Retrospective Memory Questionnaire" (PRMQ), in our cross-sectional study. Both measures referred to two periods: the pre-pandemic period (T0) and the moment of survey administration (T1) (December 28th, 2021, to February 6th, 2022).

Results

207 Italian participants accessed the survey, out of which 189 participants were included in the final sample. The majority of the participants were females, and their age ranged from 55 to 65 years. The study revealed a significant increase in the total PRMQ score at T1 compared to T0 (p = 0.02). However, no significant differences were found between PRMQ and SMCQ scores of COVID-19-negative individuals and those who tested positive for COVID-19 in the last 12 months from the date of completing the survey. McNemar's test showed a statistically significant increase in the score of item 1 ("Do you think that you have a memory problem?" (p = 0.016) and item 10 ("Do you lose objects more often than you did previously") (0.019) of the SMCQ, while for the PRMQ, significant increases were found in several individual items.

Conclusions

our study suggests that subjective memory complaints increased during the pandemic, potentially due to the compound effects of stress and social isolation, rather than solely due to COVID-19 infection. Although a marginal association between COVID-19 and reported prospective memory issues was detected, further investigation is warranted to understand its persistent effects.

Reported neurological symptoms after severe acute respiratory syndrome coronavirus type 2 infection: A systematic diagnostic approach

BACKGROUND AND PURPOSE

Following increasing demands of patients with suspected neurological symptoms after infection with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), the Department of Neurology at the Medical University of Vienna established a new outpatient clinic to systematically assess, diagnose, and document neurological complaints potentially associated with a prior SARS-CoV-2 infection.

METHODS

The data presented here include prospectively collected 156 outpatients from May 2021 to April 2022. Patients underwent semistandardized interviewing about symptoms with reported onset after SARS-CoV-2 infection, neurological examination, and comprehensive diagnostic workup.

RESULTS

Reported new onset symptoms after infection included fatigue (77.6%), subjective cognitive impairment (72.4%), headache (47.7%), loss of smell and/or taste (43.2%), and sleep disturbances (42.2%). Most patients had a mild coronavirus disease (COVID-19) disease course (84%) and reported comorbidities (71%), of which the most frequent were psychiatric disorders (34%). Frequency of symptoms was not associated with age, sex, or severity of COVID-19 course. A comprehensive diagnostic workup revealed no neurological abnormalities in the clinical examination, or electrophysiological or imaging assessments in the majority of patients (n = 143, 91.7%). Neuropsychological assessment of a subgroup of patients (n = 28, 17.9%) showed that cognitive impairments in executive functions and attention, anxiety, depression, and somatization symptoms were highly common.

CONCLUSIONS

In this systematic registry, we identified fatigue, cognitive impairment, and headache as the most frequently reported persisting complaints after SARS-CoV-2 infection. Structural neurological findings were rare. We also suspect a link between the growing burden of the COVID-19 pandemic on personal lives and the increase in reported neurological and psychiatric complaints.

Impairment of quality of life due to COVID-19-induced long-term olfactory dysfunction

Introduction

Olfactory dysfunction is one of many long-lasting symptoms associated with COVID-19, estimated to affect approximately 60% of individuals and often lasting several months after infection. The associated daily life problems can cause a decreased quality of life.

Methods

Here, we assessed the association between perceived quality of life and both qualitative and quantitative olfactory function (distorted and weakened sense of smell, respectively) in 58 individuals who had undergone confirmed SARS-CoV-2 infection and who complained about olfactory dysfunction.

Results

Participants with large quantitative olfactory dysfunction experienced a greater reduction in their quality of life. Moreover, our participants had a high prevalence of qualitative olfactory dysfunction (81%) with a significant correlation between qualitative olfactory dysfunction and daily life impairment. Strong drivers of low quality of life assessments were lack of enjoyment of food as well as worries related to coping with long-term dysfunctions.

Discussion

These results stress the clinical importance of assessing qualitative olfactory dysfunction and the need to develop relevant interventions. Given the poor self-rated quality of life observed, healthcare systems should consider developing support structures, dietary advice, and guidelines adapted to individuals experiencing qualitative olfactory dysfunction.