ArticleHuman brain mapping2022
Olfactory loss and brain connectivity after COVID-19.
Article in Human brain mapping, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 52 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
52 citing papers in PubMed, 2 syntheses or guidelines pooled it, 71 citations in OpenAlex.
- Functional brain alterations in COVID-19 patients using resting-state fMRI: a systematic review.Brain imaging and behavior · 2024Pooled it
- Post-COVID-19 conditions: a systematic review on advanced magnetic resonance neuroimaging findings.Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2024Pooled it
- Functional brain abnormalities in post COVID-19 condition and their relationship with cognition.Scientific reports · 2025Trial
- Effects of hyperbaric oxygen therapy on functional and structural connectivity in post-COVID-19 condition patients: A randomized, sham-controlled trial.NeuroImage. Clinical · 2022Trial
- Investigation of BOLD signal intensities in long COVID patients using 7T functional MRI.Brain, behavior, & immunity - health · 2026Article
- Dynamic recovery of piriform cortex function and its impact on cognitive processing speed following mild COVID-19.BMC neurology · 2026Article
- Mendelian randomization analyses support causal relationships between COVID-19 and changes in brain structure and function.European archives of psychiatry and clinical neuroscience · 2026Article
- Distinct functional connectivity patterns in myalgic encephalomyelitis and long COVID patients during cognitive fatigue: a 7 Tesla task-fMRI study.Journal of translational medicine · 2026Article
- COVID-19-associated neurological and psychological manifestations.Nature reviews. Disease primers · 2025Review
- Functional olfactory impairment and fatigue in post-COVID-19 syndrome including ME/CFS - a longitudinal prospective observational study.Brain, behavior, & immunity - health · 2025Article
- The plasticity of olfactory learning in culinary students and matched controls.Brain imaging and behavior · 2025Article
- Olfactory Dysfunction and Cognitive Decline: Are They Related?Current allergy and asthma reports · 2025Review
- Olfactory identification impairment in cerebral small-vessel disease indicates cognitive network disconnection and predicts accelerated cognitive decline.Journal of neurology · 2025Article
- Mapping the Olfactory Brain: A Systematic Review of Structural and Functional Magnetic Resonance Imaging Changes Following COVID-19 Smell Loss.Brain sciences · 2025Review
- The Bulb, the Brain and the Being: New Insights into Olfactory System Anatomy, Organization and Connectivity.Brain sciences · 2025Article
- Persistent dysfunctions of brain metabolic connectivity in long-covid with cognitive symptoms.European journal of nuclear medicine and molecular imaging · 2025Article
- Olfactory Network Disruptions as Mediators of Cognitive Impairment in De Novo Parkinson's Disease.CNS neuroscience & therapeutics · 2025Article
- Cognitive deficits and cortical volume loss in COVID-19-related hyposmia.European journal of neurology · 2025Article
- Functional connectivity of default mode network in non-hospitalized patients with post-COVID cognitive complaints.Frontiers in neuroscience · 2025Article
- Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
To address the impact of COVID-19 olfactory loss on the brain, we analyzed the neural connectivity of the central olfactory system in recently SARS-CoV-2 infected subjects with persisting olfactory impairment (hyposmia). Twenty-seven previously SARS-CoV-2 infected subjects (10 males, mean age ± SD 40.0 ± 7.6 years) with clinically confirmed COVID-19 related hyposmia, and eighteen healthy, never SARS-CoV-2 infected, normosmic subjects (6 males, mean age ± SD 36.0 ± 7.1 years), were recruited in a 3 Tesla MRI study including high angular resolution diffusion and resting-state functional MRI acquisitions. Specialized metrics of structural and functional connectivity were derived from a standard parcellation of olfactory brain areas and a previously validated graph-theoretic model of the human olfactory functional network. These metrics were compared between groups and correlated to a clinical index of olfactory impairment. On the scanning day, all subjects were virus-free and cognitively unimpaired. Compared to control, both structural and functional connectivity metrics were found significantly increased in previously SARS-CoV-2 infected subjects. Greater residual olfactory impairment was associated with more segregated processing within regions more functionally connected to the anterior piriform cortex. An increased neural connectivity within the olfactory cortex was associated with a recent SARS-CoV-2 infection when the olfactory loss was a residual COVID-19 symptom. The functional connectivity of the anterior piriform cortex, the largest cortical recipient of afferent fibers from the olfactory bulb, accounted for the inter-individual variability in the sensory impairment. Albeit preliminary, these findings could feature a characteristic brain connectivity response in the presence of COVID-19 related residual hyposmia.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.