The neuropsychological impacts of coronavirus disease 2019 in nonhospitalized patients with long coronavirus disease and brain fog - Original article

Q: What condition did the study focus on regarding COVID-19?

The study focused on long COVID in nonhospitalized patients who reported brain fog and subjective cognitive complaints.

Q: Which cognitive domains were most affected in patients?

The most affected areas were processing speed, memory recall, memory learning, and inhibitory control.

Q: Why is a comprehensive neuropsychological evaluation important for these patients?

Nearly 70% showed objective cognitive impairments despite subjective complaints and often mild symptoms, so comprehensive evaluation is needed for appropriate management.

Sep 29, 2026

Uploaded by Ivy

Background: Coronavirus disease 2019 (COVID-19) can lead to persistent symptoms, including brain fog. Limited research on long-term effects of mild COVID-19 shows inconsistent findings. This study examined which cognitive functions are most affected in nonhospitalized Asian patients with long COVID and subjective cognitive complaints. Methods: Fifty-five nonhospitalized patients completed neuropsychological screening and comprehensive tests covering memory, executive function, processing speed, and subjective emotional and disease symptoms.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages7

Reading Time18 min

AccessFree to download

Abstract

Background

Methods

Results

Conclusion

INTRODUCTION

J Chin MedAssoc Original article The neuropsychological impacts of coronavirus disease 2019 in nonhospitalized patients with long coronavirus disease and brain fog Yu-Chen Chuanga, Yu-Hsiang Chenga, Meng-Ju Tsaia, Yi-Jiun Lub, Jong-Ling Fuha,c,d,* aDivision of General Neurology, Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; bDepartment of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan, ROC; cSchool of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC; dBrain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC Abstract Background: Coronavirus disease 2019 (COVID-19) causes persistent symptoms, including brain fog. Based on limited research on the long-term consequences of mild COVID-19, which has yielded inconsistent results, we investigated which cognitive functions were most affected by COVID-19 in nonhospitalized Asian patients with long-term COVID and subjective cognitive complaints. Methods: Fifty-five nonhospitalized patients with subjective cognitive complaints after COVID infection (24 males and 31 females, mean age: 45.6 ± 14.6 years, mean duration of education: 14.4 ± 3.0 years) finished the study. Neuropsychological assessments included screening tests for overall cognition, and comprehensive tests for memory, executive function, processing speed, and subjective emotional and disease symptoms. Cognitive test scores were converted into Z-scores. Moreover, principal component analysis (PCA) was used to define cognitive domains across subtest scores. Results: Comprehensive assessments revealed cognitive impairment in 69. 1% of patients (<1 .5 SD in at least one test) . The processing speed (27 .3%), memory recall (21 .8%), memory learning (20 .0%), and inhibitory control (18 .2%) were the most affected areas. Self-reported anxiety and depression were observed in 35% and 33% of patients, respectively. Furthermore, the degree of anxiety was predictive of learning performance. Conclusion: Nearly 70% of patients with subjective cognitive complaints and long COVID had objective cognitive impairments. A comprehensive evaluation is essential for these patients, even when they present with mild symptoms. Keywords: Brain fog; Cognitive function; Long COVID; Neuropsychology 1. INTRODUCTION According to the World Health Organization (WHO), “long COVID”(post-coronavirus disease 2019 [COVID-19] condition) refers to symptoms emerging within 3 months post-initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that persist for at least 2 months without other explanation. These include physiological symptoms, including chronic cough, difficulty breathing, palpitations, chest tightness, joint soreness, and fatigue,1 as well as cognitive and emotional problems, such as impaired concentration, memory loss, insomnia, mental slowness, depression, and anxiety.2 “Brain fog” entails *Address correspondence. Dr. Jong-Ling Fuh, Division of General Neurology, Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, 201, Section 2, Shi-Pai Road, Taipei 112, Taiwan, ROC. E-mail address: jlfuh@ [vghtpe.gov.tw](vghtpe.gov.tw) (J.-L. Fuh). Conflicts of interest: Dr. Jong-Ling Fuh, an editorial board member at Journal of the Chinese Medical Association, had no role in the peer review process of or decision to publish this article. The other authors declare that they have no conflicts of interest related to the subject matter or materials discussed in this article. Journal of Chinese Medical Association. (2025) 88: 58-64. Received June 12, 2024; accepted August 29, 2024. doi: 10. 1097/JCMA.0000000000001175 Copyright © 2024, the Chinese Medical Association. This is an open access article under the CC BY-NC-ND license ([http://creativecommons.org/licenses/](http://creativecommons.org/licenses/)[ ](http://creati

FAQs

What condition did the study focus on regarding COVID-19?

The study focused on long COVID in nonhospitalized patients who reported brain fog and subjective cognitive complaints.

Which cognitive domains were most affected in patients?

The most affected areas were processing speed, memory recall, memory learning, and inhibitory control.

Why is a comprehensive neuropsychological evaluation important for these patients?

Nearly 70% showed objective cognitive impairments despite subjective complaints and often mild symptoms, so comprehensive evaluation is needed for appropriate management.

Sep 29, 2026

Uploaded by Ivy