Cognitive Impairment and Fatigue After Mild to Moderate COVID-19

NCT ID: NCT06042530

Last Updated: 2023-09-21

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Total Enrollment

100 participants

Study Classification

OBSERVATIONAL

Study Start Date

2021-04-01

Study Completion Date

2025-12-31

Brief Summary

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The primary aim of the project is to map fatigue, cognitive and visual dysfunctions and possible underlying pathophysiological mechanisms in persons with long-term symptoms after a mild to moderate COVID-19 infection. Secondary goals are to study whether covarying factors such as depression and sleep disorders contribute to the results.

Detailed Description

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The primary aim of the project is to map neuropsychological and visual dysfunctions and possible underlying pathophysiological mechanisms in patients suffering from Post-COVID condition (PCC) after a mild to moderate COVID-19 infection. Secondary goals are to study whether covarying factors such as depression and sleep disorders contribute to the results.

The main objectives are:

1. Which cognitive problems (self-reported and test results/performance based?) are typical in patients with post-COVID syndrome compared to non-symptomatic controls?
2. Which pre-existing factors affect cognitive functions and fatigue after a mild to moderate COVID-19 infection?
3. Is there a relationship between self-perceived symptoms, cognitive and visual test results, optical coherence tomography (OCT) examination, imaging results, and biomarkers in patients who have undergone mild COVID-19 infection and does this differ compared to non-symptomatic controls?
4. How are fatigue, cognitive fatigability and vision-related disorders related to neuronal correlates and changes in the retina examined with OCT and biomarkers (astocyte-derived extracellular vesicles (High Mobility Group Box 1 (Hmbg1) and S100B) and inflammatory markers) in patients who have remaining symptoms after a mild COVID-19 infection and do the results differ from what can be seen in non-symptomatic controls?
5. Are specific cognitive dysfunctions and fatigue/cognitive fatigability correlated with astocyte-derived extracellular vesicles in patients who have remaining symptoms after a mild COVID-19 infection?
6. How do symptoms evolve over one and two years?

STUDY DESIGN The study is a controlled longitudinal cohort study that includes cross-sectional sub-studies of imaging and biomarkers.

STUDY SETTING Outpatient rehabilitation clinic at the Department of Rehabilitation Medicine at Danderyd University Hospital and Karolinska University Hospital, both located in Stockholm, Sweden. At the Cognitive post-COVID clinic at Danderyd University Hospital, patients with long-term cognitive problems and fatigue are investigated after a mild to moderat (not ICU treated) COVID-19 infection. Clinical assessments are included for all participants but in a sub-study we will consecutively invite participants to also investigate vision and eye functions, brain connectivity and, biomarkers.

PARTICIPANTS PATIENTS All patients present at the Cognitive Post-COVID clinic att the Department of Rehabilitation Medicine at Danderyd University Hospital will have a medical examination. Those patients with cognitive dysfunctions related to a COVID-19 infection will be offered a comprehensive neuropsychological investigation and asked if they are interested in participating in the cohort study.

The first 100 patients are consecutively asked if they also are interested in taking biomarkers. Of these, up to 30 patients, meeting the inclusion criteria for functional Magnetic Resonance Imaging (fMRI) are asked for participation in the a sub-study including an fMRI investigation as well as an optometric and OCT investigation.

NON-SYMPTOMATIC CONTROLS 50 healthy controls who do not suffer from long term symptoms after a COVID-19 infection \>3 months from the latest infections or have not had a COVID-19 infection will be investigated for comparison. The same exclusion criteria as for the patients are applied also for the controls. The non-symptomatic controls will undergo neuropsychological examination, examination of visual functions, sampling of biomarkers, as well as fMRI examination and an OCT examination. The controls will be matched with the patients regarding age, gender and length of education.

The patients will be followed-up with questionnaires regarding current symptoms after 1 and 2 years after the neuropsychological investigation.

Conditions

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Post COVID-19 Condition Cognitive Impairment Fatigue, Mental

Study Design

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Observational Model Type

CASE_CONTROL

Study Time Perspective

CROSS_SECTIONAL

Study Groups

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Post-COVID condition

Patients experiencing persisting cognitive dysfunction and fatigue after a SARS-CoV-2 infection, three months or more after the infections

Neuropsychological investigation

Intervention Type DIAGNOSTIC_TEST

Comprehensive neuropsychological test battery covering logical reasoning, different attention functions, executive functions, visuospatial functions, different memory functions, psychomotor speed, motor functions, and smell identification

Optometric investigation

Intervention Type DIAGNOSTIC_TEST

Extended vision examination including symptom assessment, visual acuity, visual field (confrontation), eye movements, eye teaming and clinical assessment of hypersensitivity to visual stimuli.

Magnetic Resonance Imaging

Intervention Type DIAGNOSTIC_TEST

The MRI sequence protocol includes resting state fMRI before and after the participants do an established 20 min long reaction time measurement paradigm (E-prime). During the paradigm a pseudo-continious arterial spin labeling sequence (pCASL) is acquired for continuous measurement of brain perfusion. Following the functional sequences the imaging protocol also includes a high resolution 3D T1weighted sequence Magnetization Prepared Rapid Gradient Echo (MPRAGE) for brain structure, a high resolution 3D T2-weighted sequence Fluid-Attenuated Inversion Recovery (FLAIR) for pathology and a 3D susceptibility weighted image (SWI) for microvascular abnormalities.

Immunological biomarkers

Intervention Type DIAGNOSTIC_TEST

Venous blood samples (10-20 ml) are taken from the elbow crease. They are drawn in the morning, and the participants are asked to fast for 12 hours prior to sampling. They are also asked to avoid physical activity prior to blood sampling. The samples are drawn into citrated tubes.

Non-symptomatic controls

Persons experiencing no symptoms after the SARS-CoV-2 infection or have not been subject for at SARS-CoV-2 infection

Neuropsychological investigation

Intervention Type DIAGNOSTIC_TEST

Comprehensive neuropsychological test battery covering logical reasoning, different attention functions, executive functions, visuospatial functions, different memory functions, psychomotor speed, motor functions, and smell identification

Optometric investigation

Intervention Type DIAGNOSTIC_TEST

Extended vision examination including symptom assessment, visual acuity, visual field (confrontation), eye movements, eye teaming and clinical assessment of hypersensitivity to visual stimuli.

Magnetic Resonance Imaging

Intervention Type DIAGNOSTIC_TEST

The MRI sequence protocol includes resting state fMRI before and after the participants do an established 20 min long reaction time measurement paradigm (E-prime). During the paradigm a pseudo-continious arterial spin labeling sequence (pCASL) is acquired for continuous measurement of brain perfusion. Following the functional sequences the imaging protocol also includes a high resolution 3D T1weighted sequence Magnetization Prepared Rapid Gradient Echo (MPRAGE) for brain structure, a high resolution 3D T2-weighted sequence Fluid-Attenuated Inversion Recovery (FLAIR) for pathology and a 3D susceptibility weighted image (SWI) for microvascular abnormalities.

Immunological biomarkers

Intervention Type DIAGNOSTIC_TEST

Venous blood samples (10-20 ml) are taken from the elbow crease. They are drawn in the morning, and the participants are asked to fast for 12 hours prior to sampling. They are also asked to avoid physical activity prior to blood sampling. The samples are drawn into citrated tubes.

Interventions

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Neuropsychological investigation

Comprehensive neuropsychological test battery covering logical reasoning, different attention functions, executive functions, visuospatial functions, different memory functions, psychomotor speed, motor functions, and smell identification

Intervention Type DIAGNOSTIC_TEST

Optometric investigation

Extended vision examination including symptom assessment, visual acuity, visual field (confrontation), eye movements, eye teaming and clinical assessment of hypersensitivity to visual stimuli.

Intervention Type DIAGNOSTIC_TEST

Magnetic Resonance Imaging

The MRI sequence protocol includes resting state fMRI before and after the participants do an established 20 min long reaction time measurement paradigm (E-prime). During the paradigm a pseudo-continious arterial spin labeling sequence (pCASL) is acquired for continuous measurement of brain perfusion. Following the functional sequences the imaging protocol also includes a high resolution 3D T1weighted sequence Magnetization Prepared Rapid Gradient Echo (MPRAGE) for brain structure, a high resolution 3D T2-weighted sequence Fluid-Attenuated Inversion Recovery (FLAIR) for pathology and a 3D susceptibility weighted image (SWI) for microvascular abnormalities.

Intervention Type DIAGNOSTIC_TEST

Immunological biomarkers

Venous blood samples (10-20 ml) are taken from the elbow crease. They are drawn in the morning, and the participants are asked to fast for 12 hours prior to sampling. They are also asked to avoid physical activity prior to blood sampling. The samples are drawn into citrated tubes.

Intervention Type DIAGNOSTIC_TEST

Eligibility Criteria

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Inclusion Criteria

• Persons 18 years and older with a history of (\> 3 months) verified COVID-19 (PCR / rapid test / antibody) or an infection that is most likely a SARS-CoV-2 infection (e.g., a close relative had a verified infection that coincided in time with the patient's illness) and who have persistent problems with cognitive impairment or fatigue affecting the return to previous activities / employment.

Exclusion Criteria

* Dominant recurrent and / or fluctuating symptoms of infection, circulatory, respiratory or cardiac problems.
* Co-morbidities that may cause cognitive impairment such as neurodegenerative disease, substance abuse, severe mental illness (eg. schizophrenia, mano depressive disorder) or severe depression.
* Not fluent in Swedish, as test and self-reports rely on good mastering of the Swedish language.
* Severe premorbid visual impairment.

Additionally for the fMRI study:

* Not verified SARS-CoV-2 infection with a Polymerase Chain Reaction (PCR) / rapid test / antibody review
* Traumatic brain injury
* Neuropsychiatric disease such as diagnosed ADHD or autism
* Younger than 25 years or older than 55 years (to avoid the risk that the brain is not fully developed or that there is a risk of age-related changes in the brain).
* MRI contraindications (such as metal objects in the body, fear of cramped spaces, pregnancy, body weight over 130 kg), and left-handedness (to increase the likelihood of uniform topological lateralization in the cohort).
Minimum Eligible Age

18 Years

Maximum Eligible Age

65 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Karolinska Institutet

OTHER

Sponsor Role collaborator

Karolinska University Hospital

OTHER

Sponsor Role collaborator

Uppsala University Hospital

OTHER

Sponsor Role collaborator

Danderyd Hospital

OTHER

Sponsor Role lead

Responsible Party

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Marika Moller

Associate Professor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Kristian Borg, Professor

Role: STUDY_DIRECTOR

Karolinska Institutet

Marika C Möller, PhD

Role: PRINCIPAL_INVESTIGATOR

Department of Rehabilitation Medicine, Danderyd University Hospital

Locations

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Department of Rehabilitation Medicine, Danderyd Hospital

Stockholm, , Sweden

Site Status RECRUITING

Countries

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Sweden

Central Contacts

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Marika C Möller, PhD

Role: CONTACT

+46812358555

Kristian Borg, Professor

Role: CONTACT

+46704657065

Facility Contacts

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Marika C Möller, PhD

Role: primary

+46812358555

Kristian Borg, Professor

Role: backup

+46704657065

References

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Tsampasian V, Elghazaly H, Chattopadhyay R, Debski M, Naing TKP, Garg P, Clark A, Ntatsaki E, Vassiliou VS. Risk Factors Associated With Post-COVID-19 Condition: A Systematic Review and Meta-analysis. JAMA Intern Med. 2023 Jun 1;183(6):566-580. doi: 10.1001/jamainternmed.2023.0750.

Reference Type BACKGROUND
PMID: 36951832 (View on PubMed)

Al-Aly Z, Bowe B, Xie Y. Long COVID after breakthrough SARS-CoV-2 infection. Nat Med. 2022 Jul;28(7):1461-1467. doi: 10.1038/s41591-022-01840-0. Epub 2022 May 25.

Reference Type BACKGROUND
PMID: 35614233 (View on PubMed)

Graham EL, Clark JR, Orban ZS, Lim PH, Szymanski AL, Taylor C, DiBiase RM, Jia DT, Balabanov R, Ho SU, Batra A, Liotta EM, Koralnik IJ. Persistent neurologic symptoms and cognitive dysfunction in non-hospitalized Covid-19 "long haulers". Ann Clin Transl Neurol. 2021 May;8(5):1073-1085. doi: 10.1002/acn3.51350. Epub 2021 Mar 30.

Reference Type BACKGROUND
PMID: 33755344 (View on PubMed)

Premraj L, Kannapadi NV, Briggs J, Seal SM, Battaglini D, Fanning J, Suen J, Robba C, Fraser J, Cho SM. Mid and long-term neurological and neuropsychiatric manifestations of post-COVID-19 syndrome: A meta-analysis. J Neurol Sci. 2022 Mar 15;434:120162. doi: 10.1016/j.jns.2022.120162. Epub 2022 Jan 29.

Reference Type BACKGROUND
PMID: 35121209 (View on PubMed)

Ceban F, Ling S, Lui LMW, Lee Y, Gill H, Teopiz KM, Rodrigues NB, Subramaniapillai M, Di Vincenzo JD, Cao B, Lin K, Mansur RB, Ho RC, Rosenblat JD, Miskowiak KW, Vinberg M, Maletic V, McIntyre RS. Fatigue and cognitive impairment in Post-COVID-19 Syndrome: A systematic review and meta-analysis. Brain Behav Immun. 2022 Mar;101:93-135. doi: 10.1016/j.bbi.2021.12.020. Epub 2021 Dec 29.

Reference Type BACKGROUND
PMID: 34973396 (View on PubMed)

Klironomos S, Tzortzakakis A, Kits A, Ohberg C, Kollia E, Ahoromazdae A, Almqvist H, Aspelin A, Martin H, Ouellette R, Al-Saadi J, Hasselberg M, Haghgou M, Pedersen M, Petersson S, Finnsson J, Lundberg J, Falk Delgado A, Granberg T. Nervous System Involvement in Coronavirus Disease 2019: Results from a Retrospective Consecutive Neuroimaging Cohort. Radiology. 2020 Dec;297(3):E324-E334. doi: 10.1148/radiol.2020202791. Epub 2020 Jul 30.

Reference Type BACKGROUND
PMID: 32729812 (View on PubMed)

Helms J, Tacquard C, Severac F, Leonard-Lorant I, Ohana M, Delabranche X, Merdji H, Clere-Jehl R, Schenck M, Fagot Gandet F, Fafi-Kremer S, Castelain V, Schneider F, Grunebaum L, Angles-Cano E, Sattler L, Mertes PM, Meziani F; CRICS TRIGGERSEP Group (Clinical Research in Intensive Care and Sepsis Trial Group for Global Evaluation and Research in Sepsis). High risk of thrombosis in patients with severe SARS-CoV-2 infection: a multicenter prospective cohort study. Intensive Care Med. 2020 Jun;46(6):1089-1098. doi: 10.1007/s00134-020-06062-x. Epub 2020 May 4.

Reference Type BACKGROUND
PMID: 32367170 (View on PubMed)

Heslin KP, Haruna A, George RA, Chen S, Nobel I, Anderson KB, Faraone SV, Zhang-James Y. Association Between ADHD and COVID-19 Infection and Clinical Outcomes: A Retrospective Cohort Study From Electronic Medical Records. J Atten Disord. 2023 Jan;27(2):169-181. doi: 10.1177/10870547221129305. Epub 2022 Oct 20.

Reference Type BACKGROUND
PMID: 36264064 (View on PubMed)

Dobryakova E, DeLuca J, Genova HM, Wylie GR. Neural correlates of cognitive fatigue: cortico-striatal circuitry and effort-reward imbalance. J Int Neuropsychol Soc. 2013 Sep;19(8):849-53. doi: 10.1017/S1355617713000684. Epub 2013 Jul 10.

Reference Type BACKGROUND
PMID: 23842042 (View on PubMed)

Nordin LE, Moller MC, Julin P, Bartfai A, Hashim F, Li TQ. Post mTBI fatigue is associated with abnormal brain functional connectivity. Sci Rep. 2016 Feb 16;6:21183. doi: 10.1038/srep21183.

Reference Type BACKGROUND
PMID: 26878885 (View on PubMed)

Aceti A, Margarucci LM, Scaramucci E, Orsini M, Salerno G, Di Sante G, Gianfranceschi G, Di Liddo R, Valeriani F, Ria F, Simmaco M, Parnigotto PP, Vitali M, Romano Spica V, Michetti F. Serum S100B protein as a marker of severity in Covid-19 patients. Sci Rep. 2020 Oct 29;10(1):18665. doi: 10.1038/s41598-020-75618-0.

Reference Type BACKGROUND
PMID: 33122776 (View on PubMed)

Cantor F. Central and peripheral fatigue: exemplified by multiple sclerosis and myasthenia gravis. PM R. 2010 May;2(5):399-405. doi: 10.1016/j.pmrj.2010.04.012.

Reference Type BACKGROUND
PMID: 20656621 (View on PubMed)

Tahyra ASC, Calado RT, Almeida F. The Role of Extracellular Vesicles in COVID-19 Pathology. Cells. 2022 Aug 11;11(16):2496. doi: 10.3390/cells11162496.

Reference Type BACKGROUND
PMID: 36010572 (View on PubMed)

Wallensten J, Nager A, Asberg M, Borg K, Beser A, Wilczek A, Mobarrez F. Leakage of astrocyte-derived extracellular vesicles in stress-induced exhaustion disorder: a cross-sectional study. Sci Rep. 2021 Jan 21;11(1):2009. doi: 10.1038/s41598-021-81453-8.

Reference Type BACKGROUND
PMID: 33479350 (View on PubMed)

Kanberg N, Ashton NJ, Andersson LM, Yilmaz A, Lindh M, Nilsson S, Price RW, Blennow K, Zetterberg H, Gisslen M. Neurochemical evidence of astrocytic and neuronal injury commonly found in COVID-19. Neurology. 2020 Sep 22;95(12):e1754-e1759. doi: 10.1212/WNL.0000000000010111. Epub 2020 Jun 16.

Reference Type BACKGROUND
PMID: 32546655 (View on PubMed)

Bruck E, Lasselin J; HICUS study group; Andersson U, Sackey PV, Olofsson PS. Prolonged elevation of plasma HMGB1 is associated with cognitive impairment in intensive care unit survivors. Intensive Care Med. 2020 Apr;46(4):811-812. doi: 10.1007/s00134-020-05941-7. Epub 2020 Feb 26. No abstract available.

Reference Type BACKGROUND
PMID: 32103282 (View on PubMed)

Okuma Y, Wake H, Teshigawara K, Takahashi Y, Hishikawa T, Yasuhara T, Mori S, Takahashi HK, Date I, Nishibori M. Anti-High Mobility Group Box 1 Antibody Therapy May Prevent Cognitive Dysfunction After Traumatic Brain Injury. World Neurosurg. 2019 Feb;122:e864-e871. doi: 10.1016/j.wneu.2018.10.164. Epub 2018 Nov 2.

Reference Type BACKGROUND
PMID: 30391757 (View on PubMed)

Ariza M, Cano N, Segura B, Adan A, Bargallo N, Caldu X, Campabadal A, Jurado MA, Mataro M, Pueyo R, Sala-Llonch R, Barrue C, Bejar J, Cortes CU; NAUTILUS-Project Collaborative Group; Junque C, Garolera M. Neuropsychological impairment in post-COVID condition individuals with and without cognitive complaints. Front Aging Neurosci. 2022 Oct 20;14:1029842. doi: 10.3389/fnagi.2022.1029842. eCollection 2022.

Reference Type BACKGROUND
PMID: 36337708 (View on PubMed)

Kelly KM, Anghinah R, Kullmann A, Ashmore RC, Synowiec AS, Gibson LC, Manfrinati L, de Araujo A, Spera RR, Brucki SMD, Tuma RL, Braverman A, Kiderman A. Oculomotor, vestibular, reaction time, and cognitive tests as objective measures of neural deficits in patients post COVID-19 infection. Front Neurol. 2022 Sep 12;13:919596. doi: 10.3389/fneur.2022.919596. eCollection 2022.

Reference Type BACKGROUND
PMID: 36188407 (View on PubMed)

Marinho PM, Marcos AAA, Romano AC, Nascimento H, Belfort R Jr. Retinal findings in patients with COVID-19. Lancet. 2020 May 23;395(10237):1610. doi: 10.1016/S0140-6736(20)31014-X. Epub 2020 May 12. No abstract available.

Reference Type BACKGROUND
PMID: 32405105 (View on PubMed)

Smets EM, Garssen B, Bonke B, De Haes JC. The Multidimensional Fatigue Inventory (MFI) psychometric qualities of an instrument to assess fatigue. J Psychosom Res. 1995 Apr;39(3):315-25. doi: 10.1016/0022-3999(94)00125-o.

Reference Type BACKGROUND
PMID: 7636775 (View on PubMed)

Zigmond AS, Snaith RP. The hospital anxiety and depression scale. Acta Psychiatr Scand. 1983 Jun;67(6):361-70. doi: 10.1111/j.1600-0447.1983.tb09716.x.

Reference Type BACKGROUND
PMID: 6880820 (View on PubMed)

Sinclair VG, Wallston KA. The development and psychometric evaluation of the Brief Resilient Coping Scale. Assessment. 2004 Mar;11(1):94-101. doi: 10.1177/1073191103258144.

Reference Type BACKGROUND
PMID: 14994958 (View on PubMed)

Nasreddine ZS, Phillips NA, Bedirian V, Charbonneau S, Whitehead V, Collin I, Cummings JL, Chertkow H. The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment. J Am Geriatr Soc. 2005 Apr;53(4):695-9. doi: 10.1111/j.1532-5415.2005.53221.x.

Reference Type BACKGROUND
PMID: 15817019 (View on PubMed)

Wechsler D. WAIS-IV technical and interpretive manual. San Antonio, Tex.: Psychological Corporation: Pearson; 2008.

Reference Type BACKGROUND

Delis DC, Kaplan E, Kramer JH. D-KEFS. Examiner´s manual. San Antonio: The Psychological Corporation, a Harcourt Assessment Company; 2001.

Reference Type BACKGROUND

Kobal G, Hummel T, Sekinger B, Barz S, Roscher S, Wolf S. "Sniffin' sticks": screening of olfactory performance. Rhinology. 1996 Dec;34(4):222-6.

Reference Type BACKGROUND
PMID: 9050101 (View on PubMed)

Buschke H. Selective reminding for analysis of memory and learning. Journal of Verbal Learning & Verbal Behavior. 1973;12(5):543-50.

Reference Type BACKGROUND

Meyers JE, Meyers KR. Rey Complex Figure Test and Recognition Trial Professional Manual. Odessa: Psychological Assessment Resources, Inc. ; 1995.

Reference Type BACKGROUND

Ruff RM, Allen CC. Ruff 2 & 7 Selective Attention Test. Lutz: Psychological Assessment Resources, Inc.; 1996.

Reference Type BACKGROUND

Garzia RP, Richman JE, Nicholson SB, Gaines CS. A new visual-verbal saccade test: the development eye movement test (DEM). J Am Optom Assoc. 1990 Feb;61(2):124-35.

Reference Type BACKGROUND
PMID: 2313029 (View on PubMed)

Moller MC, Nordin LE, Bartfai A, Julin P, Li TQ. Fatigue and Cognitive Fatigability in Mild Traumatic Brain Injury are Correlated with Altered Neural Activity during Vigilance Test Performance. Front Neurol. 2017 Sep 21;8:496. doi: 10.3389/fneur.2017.00496. eCollection 2017.

Reference Type BACKGROUND
PMID: 28983280 (View on PubMed)

Rouse MW, Borsting EJ, Mitchell GL, Scheiman M, Cotter SA, Cooper J, Kulp MT, London R, Wensveen J; Convergence Insufficiency Treatment Trial Group. Validity and reliability of the revised convergence insufficiency symptom survey in adults. Ophthalmic Physiol Opt. 2004 Sep;24(5):384-90. doi: 10.1111/j.1475-1313.2004.00202.x.

Reference Type BACKGROUND
PMID: 15315652 (View on PubMed)

Laukkanen H, Scheiman M, Hayes JR. Brain Injury Vision Symptom Survey (BIVSS) Questionnaire. Optom Vis Sci. 2017 Jan;94(1):43-50. doi: 10.1097/OPX.0000000000000940.

Reference Type BACKGROUND
PMID: 28027193 (View on PubMed)

Lim J, Wu WC, Wang J, Detre JA, Dinges DF, Rao H. Imaging brain fatigue from sustained mental workload: an ASL perfusion study of the time-on-task effect. Neuroimage. 2010 Feb 15;49(4):3426-35. doi: 10.1016/j.neuroimage.2009.11.020. Epub 2009 Nov 24.

Reference Type BACKGROUND
PMID: 19925871 (View on PubMed)

Other Identifiers

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2021-03907_Cognition COVID-19

Identifier Type: -

Identifier Source: org_study_id

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