Evidence map›Paper›PMID 42092802›Full record

ArticleBMC neurology2026

Dynamic recovery of piriform cortex function and its impact on cognitive processing speed following mild COVID-19.

Hyeonseok Jeong, Youngeun Shim, Yoonji Joo, Yejin Kim, Chaewon Suh, Yunjung Jin, Harin Song, In Kyoon Lyoo, Sujung Yoon

Abstract read
In one paragraph

Article in BMC neurology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
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0citing papers in PubMed
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1 · What the graph read from 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.

2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Hyeonseok Jeong *Ewha Brain Institute, Ewha Womans University, Seoul, South Korea.
Youngeun Shim *Ewha Brain Institute, Ewha Womans University, Seoul, South Korea.
Yoonji JooEwha Brain Institute, Ewha Womans University, Seoul, South Korea.
Yejin KimEwha Brain Institute, Ewha Womans University, Seoul, South Korea.
Chaewon SuhEwha Brain Institute, Ewha Womans University, Seoul, South Korea.
Yunjung JinEwha Brain Institute, Ewha Womans University, Seoul, South Korea.
Harin SongEwha Brain Institute, Ewha Womans University, Seoul, South Korea.
In Kyoon LyooEwha Brain Institute, Ewha Womans University, Seoul, South Korea. inkylyoo@ewha.ac.kr.
Sujung YoonEwha Brain Institute, Ewha Womans University, Seoul, South Korea. sujungjyoon@ewha.ac.kr.

Funding

Korea Food Research Institute E0232201National Research Foundation of Korea RS-2020-NR049587National Research Foundation of Korea RS-2024-00440371National Research Foundation of Korea RS-2025-16070333
6 · The paper itself

Abstract

backgroundAlthough the neurological sequelae of severe COVID-19 are increasingly recognized, the long-term neural impact of uncomplicated mild SARS-CoV-2 infection remains insufficiently characterized. This study investigated post-infection alterations in piriform cortex activity, a region central to olfactory processing and integrative cognitive-emotional networks, and their associations with cognitive outcomes in adults.

methodsFifty adults with pre- and post-SARS-CoV-2 magnetic resonance imaging (MRI) and clinical/neuropsychological data were analyzed. A demographically matched control group of 50 individuals without prior COVID-19 or vaccination was included. Resting-state functional MRI assessed amplitude of low-frequency fluctuations (ALFF) within the piriform cortex as an index of regional neural activity.

resultsBaseline piriform ALFF did not differ between the two groups (p = 0.421). Following infection, piriform ALFF exhibited a significant quadratic trajectory (p = 0.003), characterized by early elevation relative to baseline, a decline to a nadir at approximately three months, and subsequent recovery toward baseline levels by six months. Greater acute COVID-19 symptom burden correlated with higher piriform ALFF (β = 0.34, p = 0.017). Elevated ALFF was associated with reduced processing speed (β = -0.52, p = 0.001). Mediation analysis demonstrated that piriform ALFF significantly mediated the relationship between symptom burden and processing speed (indirect effect b = -0.081, p = 0.037).

conclusionsPiriform cortex function demonstrated a dynamic, nonlinear pattern within six months after mild COVID-19, marked by early hyperactivity, later downregulation, and gradual normalization. Altered piriform activity mediated the association between symptom burden and processing speed deficits, suggesting transient post-infection neurophysiological disruption with potential relevance to cognitive symptoms. Longitudinal follow-up is warranted to clarify underlying mechanisms and long-term implications.

Indexed as

COVID-19Piriform CortexProcessing SpeedRecovery of FunctionAdultCognitionFemaleHumansMagnetic Resonance ImagingMaleMiddle AgedNeuropsychological TestsPost-Acute COVID-19 SyndromeAmplitude of low‑frequency fluctuationsCOVID-19Functional magnetic resonance imagingNeuroplasticityPiriform cortexProcessing speed

Identifiers

PMID42092802
PMCPMC13242123

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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.