Persistent olfactory dysfunction in mild COVID-19 patients: A descriptive study of the characteristics and association with other symptoms

García-Meléndez, David Dylan; Morales-Casado, María Isabel; Quintana-Castro, Pilar; Alonso, Carlos Marsal

doi:10.1016/j.medcli.2022.11.018

Cited by 4 publications

(7 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The present study indicated that most patients who recovered from COVID-19 with persistent hyposmia 4 months after the end of the infection still presented with mild prefrontal function deficits, confirming the hypothesis about a retrograde effect of the SARS-CoV-2 virus on the brain regions contiguous to the entry zone. Recent studies confirmed the long-term persistence of both smell and cognitive dysfunction as brain fog in post-COVID-19 patients (García-Meléndez et al, 2023) The present study indicated that most patients who recovered from COVID-19 with persistent hyposmia 4 months after the end of the infection still presented with mild prefrontal function deficits, confirming the hypothesis about a retrograde effect of the SARS-CoV-2 virus on the brain regions contiguous to the entry zone.…”

Section: Discussionsupporting

confidence: 87%

Prefrontal dysfunction in post-COVID-19 hyposmia: an EEG/fNIRS study

Clemente,

La Rocca,

Quaranta

et al. 2023

Front. Hum. Neurosci.

View full text Add to dashboard Cite

IntroductionSubtle cognitive dysfunction and mental fatigue are frequent after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, characterizing the so-called long COVID-19 syndrome. This study aimed to correlate cognitive, neurophysiological, and olfactory function in a group of subjects who experienced acute SARS-CoV-2 infection with persistent hyposmia at least 12 weeks before the observation.MethodsFor each participant (32 post-COVID-19 patients and 16 controls), electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) data were acquired using an integrated EEG–fNIRS system during the execution of a P300 odd-ball task and a Stroop test. The Sniffin' Sticks test was conducted to assess subjects' olfactory performance. The Montreal Cognitive Assessment (MoCA) and the Frontal Assessment Battery (FAB) were also administered.ResultsThe post-COVID-19 group consisted of 32 individuals (20 women and 12 men) with an average education level of 12.9 ± 3.12 years, while the control group consisted of 16 individuals (10 women and 6 men) with an average education level of 14.9 ± 3.2 years. There were no significant differences in gender (X2 = 0, p = 1) or age between the two groups (age 44.81 ± 13.9 vs. 36.62 ± 11.4, p = 0.058). We identified a lower concentration of oxyhemoglobin (p < 0.05) at the prefrontal cortical level in post-COVID-19 subjects during the execution of the Stroop task, as well as a reduction in the amplitude of the P3a response. Moreover, we found that post-COVID-19 subjects performed worst at the MoCA screening test (p = 0.001), Sniffin's Sticks test (p < 0.001), and Stroop task response latency test (p < 0.001).ConclusionsThis study showed that post-COVID-19 patients with persistent hyposmia present mild deficits in prefrontal function, even 4 months after the end of the infection. These deficits, although subtle, could have long-term implications for quality of life and cognitive wellbeing. It is essential to continue monitoring and evaluating these patients to better understand the extent and duration of cognitive impairments associated with long COVID-19.

show abstract

Section: Discussionsupporting

confidence: 87%

Prefrontal dysfunction in post-COVID-19 hyposmia: an EEG/fNIRS study

Clemente,

La Rocca,

Quaranta

et al. 2023

Front. Hum. Neurosci.

View full text Add to dashboard Cite

show abstract

“…The fact that hyposmia is more prevalent than anosmia in patients with long COVID caught our attention. These findings were also found in the study by [18], which used the Sniffin´ Sticks test to quantify olfactory disorders. The study also found a higher prevalence of hyposmia than anosmia (41.9% and 30.2% respectively).…”

Section: Discussionsupporting

confidence: 69%

“…Our sample was made up of women (90%), which is in line with several studies, where the female sex is considered a risk factor for long COVID [2,18,19]. In the systematic review with meta-analysis conducted by [2], of the 16 articles used to analyze sex as a risk factor for the development of long COVID symptoms, in 14 of them, the female sex was associated with greater risk for long COVID.…”

Section: Discussionmentioning

confidence: 82%

Long Covid-19 Syndrome: the Prevalence of Neuropsychiatric Symptoms in Patients with Olfactory Disorders

Santos Sales,

Beiral Hammerle,

da Silva Souza

et al. 2023

View full text Add to dashboard Cite

Background: Among the frequently reported symptoms in long-term COVID-19 syndrome, we can highlight olfactory disorders depression, anxiety, and fatigue. OD can affect people's physical and mental health and can lead to neuropsychiatric symptoms. Objective: Determine the prevalence of symptoms of depression, anxiety, and fatigue in patients with olfactory disorders induced by long-term COVID-19; and investigate this impact on the quality of life. Methods: The study included 30 patients with confirmed long-term COVID-19, with persistent complaints of olfactory dysfunction. OD was evaluated by the connecticut smell test. Neuropsychiatric disorders were evaluated by the fatigue severity and hospital anxiety and depression scales. Quality of life was accessed using the SF-36. Results: 70% of the patients had different degrees of hyposmia and 20% had anosmia. The most prevalent symptom was depression with 66.7% of the sample. More than half of patients also had symptoms of anxiety and fatigue (53,3% both). The most affected dimensions of SF-36 were emotional, vitality, role physical and mental health (36.6 ± 44.0, 44.3 ± 28.7, 47.5 ± 42.7, 49.8 ± 24.7 respectively). There was a moderate negative correlation between symptoms of depression and the physical role and mental health dimension. There was a moderate negative correlation between anxiety and general health, vitality, social functioning, and mental health dimensions. Symptoms of fatigue obtained a moderate negative correlation in the physical function dimension. Conclusion: The prevalence of symptoms of depression, anxiety and fatigue is high in patients with olfactory disorders induced by long-term COVID-19, with a negative impact on the quality of life of these patients, highlighting the role emotional aspect.

show abstract

“…Even though this could have been caused by a sample bias in our study, our finding corroborates previous results from Akbari and colleagues 39 who found significant better identification scores in smokers but also previous studies 41,42 which reported that COVID‐19‐related OD is less frequent in patients with a smoking habit. Prevalence of parosmia in our population (80%) was higher when compared to previous studies, although this varies widely across different studies in the literature and reported to be between 43% at 6 months and 70.9% when evaluated at 1 year 43–46 . A higher prevalence of parosmia in our group of patients could be explained either by a longer OD in our population (1.4 years) or by the fact that only patients with a self‐reported long‐term OD were referred to our long‐COVID smell clinic and included in the study.…”

Section: Discussioncontrasting

confidence: 58%

“…Prevalence of parosmia in our population (80%) was higher when compared to previous studies, although this varies widely across different studies in the literature and reported to be between 43% at 6 months and 70.9% when evaluated at 1 year. [43][44][45][46] A higher prevalence of parosmia in our group of patients could be explained either by a longer OD in our population (1.4 years) or by the fact that only patients with a self-reported long-term OD were referred to our long-COVID smell clinic and included in the study. Although past studies have reported a possible influence of parosmia 14,15 and phantosmia 10 on smell recovery our analysis did not confirm that.…”

Section: Discussionmentioning

confidence: 99%

Clinical factors influencing olfactory performance in patients with persistent COVID‐19 smell loss longer than 1 year

Pendolino,

Ottaviano,

Navaratnam

et al. 2023

Laryngoscope Investig Oto

View full text Add to dashboard Cite

ObjectivesFactors affecting persistence of COVID‐19‐related olfactory dysfunction (OD) remain partially unknown. We aim to evaluate the clinical factors which could influence olfactory performance in patients with persistent COVID‐19‐related smell loss.MethodsA retrospective analysis of 100 patients with persistent COVID‐19‐related OD was performed between October 2020 and December 2022 at a single‐center long‐COVID smell clinic. All subjects underwent smell assessment using Sniffin' Sticks (S'S) extended test, nasal endoscopy, nasal airflow evaluation (peak nasal inspiratory flow [PNIF]), allergy test (skin prick test [SPT]) for common aeroallergens, MRI of the head and patient‐reported outcome measures (PROMs—VAS, SF‐36, Short QOD‐NS, SNOT‐22). Based on S'S score, subjects were divided into normosmics (TDI ≥ 30.75) and dysosmics (TDI < 30.75).ResultsThe median age was 42 years and the median length of patient‐reported OD was 1.4 years. 20 patients (20.0%) were normosmic at the time of S'S assessment. Dysosmic patients were found to have significantly lower scores at the SF‐36 health domains for energy/fatigue (p = .0004) and emotional wellbeing (p = .04) when compared to normosmics. A moderate correlation (r = .45–.59) between S'S scores and some PROMs was also demonstrated. At the multivariate analysis higher PNIF scores positively influenced odor threshold (p = .001) while positivity to SPT negatively influenced odor identification (p = .04).ConclusionsImpairment of nasal airflow and sensitivity to aeroallergens can negatively affect olfactory performance in COVID‐19‐related OD. Long‐COVID smell loss deeply affects QoL although recovery of olfaction can bring it back to a normal range.Level of EvidenceIV.

show abstract

Persistent olfactory dysfunction in mild COVID-19 patients: A descriptive study of the characteristics and association with other symptoms

Cited by 4 publications

References 11 publications

Prefrontal dysfunction in post-COVID-19 hyposmia: an EEG/fNIRS study

Prefrontal dysfunction in post-COVID-19 hyposmia: an EEG/fNIRS study

Long Covid-19 Syndrome: the Prevalence of Neuropsychiatric Symptoms in Patients with Olfactory Disorders

Clinical factors influencing olfactory performance in patients with persistent COVID‐19 smell loss longer than 1 year

Contact Info

Product

Resources

About