First-ever Ischemic StrokeCogStrokeNCT05653141
Post-stroke Cognitive Impairment
An observational study of First-ever Ischemic Stroke and Cognitive Performance, run by Roza Umarova at 1 site in Switzerland.
Trial summary
Present study aims to track the post-stroke cognitive trajectories and to investigate its inter-individual variability. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- First-ever Ischemic Stroke, Cognitive Performance
- How many people
- 600 participants
- Where
- 1 siteSwitzerland
- Study dates
- 17 Dec 2020to 31 Oct 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Adult, Older adult
Study population: The study recuits patients hospitalized at the Department of Neurology of the University Hospital of Bern (Inselspital)
Who may be able to join
- Age ≥18 years old
- First-ever anterior circulation ischemic stroke confirmed by routine MRI
- Time of enrollment: ≤ 10 days from stroke onset.
Who cannot join
- Previous stroke anamnestic or based on clinical imaging
- Additional stroke in posterior circulation
- Conditions that preclude the cognitive testing (e.g. delirium, intubation, reduced vigilance
- Neurological or psychiatric conditions that preclude the data interpretation (e.g. pre-stroke dementia, schizophrenia, brain tumor, regular intake of benzodiazepine, depression)
- MRI contraindication
- Native language other than German, French or Italian
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Switzerland1 site, 1 recruiting
- Recruiting
Department of Neurology, Inselspital, University Hospital Bern, University of Bern
Bern, 3010
Roza M. Umarova, PD Dr., +41316327000, roza.umarova@insel.ch
About this study
Official title: Prediction of Post-stroke Cognitive Decline and Dementia: Impact of Cognitive Reserve and Post-stroke Life Style
Present study aims to track the post-stroke cognitive trajectories and to investigate its inter-individual variability.
Read the detailed description
The study aim is to establish a model capturing patients' inter-individual variability in susceptibility to stroke damage to predict stroke-induced cognitive trajectories. This is a prospective longitudinal observational national monocentric study for 6 years (recruitment during the first 3 years). The investigators perform comprehensive neuropsychological testing in i) acute stroke phase (0-10 days post-stroke), ii) sub-acute stroke phase (3 months post-stroke), and iii) chronic stroke phase (12 months and 3 years post-stroke). At each time point, cognitive performances as well as clinical and functional status will be assessed. Furthermore, the investigators will assess the proxies of cognitive reserve and the level of post-stroke physical activity.
Analyses of the longitudinal dataset, including follow-up assessments up to 36 months post-stroke, indicated an attrition rate of up to 50%, partly attributable to post-stroke mortality. This level of attrition resulted in a substantial reduction in effective sample size and, consequently, insufficient statistical power for the planned prediction models and independent validation analyses. In particular, the reduced number of complete cases limited the robustness and generalizability of the findings. Therefore, following a recruitment pause on 02.10.2023, patient recruitment was resumed on 05.08.2025 after securing additional funding and dedicated study personnel to ensure adequate sample size for model development and validation.
- Conditions
- First-ever Ischemic Stroke, Cognitive Performance
- Keywords
- Ischemic stroke, Cognitive reserve
- Medical subject headings
- Ischemic Stroke
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Stroke patients | Adults with first-ever anterior circulation stroke |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with delayed cognitive deterioration (DCD)
The investigators will assess number of participants with deterioration of the cognitive performance in ≥2 cognitive domains on ≥ 1 Standard Deviation (1 SD).
Measured: at 3 months, at 12 months and at 36 months post-stroke
Number of participants with delayed functional deterioration
The investigators will assess number of participants with deterioration of functional disability will be defined as decrease in disability level to one point assessed via modified Rankin Scale (mRS, 0-6, whereas 0=no functional disability).
Measured: at 3 months, at 12 months and at 36 months post-stroke
Secondary outcomes (1)
Number of participants with post-stroke cognitive impairment
The investigators will assess number of participants with post-stroke cognitive impairment that is defined as at least moderate deficit (performance below -1.5 SD) in ≥ 2 cognitive domains. The cognitive performance across all basic cognitive domains is assessed using a standardized neuropsychological test battery with available normative data. The test battery includes tests from Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Trail Making Test A + B, verbal fluency, alertness test, digit span (forward and backward), Bells test, and Montreal Cognitive Assessment.
Measured: 10 days post-stroke, 3 months, 12 months and at 36 months post-stroke
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2022
- Study start17 Dec 2020
- Primary completion31 Oct 2026 (estimated)
- Study completion31 Oct 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for First-ever Ischemic StrokeStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 600 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Roza Umarova
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Roza Umarova, Insel Gruppe AG, University Hospital Bern
- Investigators
- Roza M. Umarova, PD Dr., Principal investigator, Department of Neurology, Inselspital, University Hospital Bern, University of Bern
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05653141
- Sponsor's protocol ID
- Studien-Nr. 4599
- Acronym
- CogStroke
- Status last verified
- Apr 2026
- First submitted
- 23 Nov 2022
- Last updated
- 6 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Umarova RM. Adapting the concepts of brain and cognitive reserve to post-stroke cognitive deficits: Implications for understanding neglect. Cortex. 2017 Dec;97:327-338. doi: 10.1016/j.cortex.2016.12.006. Epub 2016 Dec 16.
PubMed 28049565Gallucci L, Sperber C, Monsch AU, Kloppel S, Arnold M, Umarova RM. Improving diagnostic accuracy of the Montreal Cognitive Assessment to identify post-stroke cognitive impairment. Sci Rep. 2024 Aug 29;14(1):20125. doi: 10.1038/s41598-024-71184-x.
PubMed 39209968
Study at a glance
From the registry record, last updated by the sponsor on 6 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prediction of Post-stroke Cognitive Decline and Dementia: Impact of Cognitive Reserve and Post-stroke Life Style
- ClinicalTrials.gov ID
- NCT05653141
- Acronym / sponsor ID
- CogStroke / Studien-Nr. 4599
- Conditions
- First-ever Ischemic Stroke, Cognitive Performance
- Keywords
- Ischemic stroke, Cognitive reserve
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 600 participants (estimated)
- Lead sponsor
- Roza UmarovaUniversity, hospital or other
- Study start
- 17 Dec 2020 (actual)
- Primary completion
- 31 Oct 2026 (estimated)
- Study completion
- 31 Oct 2029 (estimated)
- First posted
- 16 Dec 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Present study aims to track the post-stroke cognitive trajectories and to investigate its inter-individual variability.
Detailed description
The study aim is to establish a model capturing patients' inter-individual variability in susceptibility to stroke damage to predict stroke-induced cognitive trajectories. This is a prospective longitudinal observational national monocentric study for 6 years (recruitment during the first 3 years). The investigators perform comprehensive neuropsychological testing in i) acute stroke phase (0-10 days post-stroke), ii) sub-acute stroke phase (3 months post-stroke), and iii) chronic stroke phase (12 months and 3 years post-stroke). At each time point, cognitive performances as well as clinical and functional status will be assessed. Furthermore, the investigators will assess the proxies of cognitive reserve and the level of post-stroke physical activity.
Analyses of the longitudinal dataset, including follow-up assessments up to 36 months post-stroke, indicated an attrition rate of up to 50%, partly attributable to post-stroke mortality. This level of attrition resulted in a substantial reduction in effective sample size and, consequently, insufficient statistical power for the planned prediction models and independent validation analyses. In particular, the reduced number of complete cases limited the robustness and generalizability of the findings. Therefore, following a recruitment pause on 02.10.2023, patient recruitment was resumed on 05.08.2025 after securing additional funding and dedicated study personnel to ensure adequate sample size for model development and validation.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Stroke patients | – | –Adults with first-ever anterior circulation stroke |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- The study recuits patients hospitalized at the Department of Neurology of the University Hospital of Bern (Inselspital)
Key inclusion criteria (3 listed)
- Age ≥18 years old
- First-ever anterior circulation ischemic stroke confirmed by routine MRI
- Time of enrollment: ≤ 10 days from stroke onset.
Key exclusion criteria (6 listed)
- Previous stroke anamnestic or based on clinical imaging
- Additional stroke in posterior circulation
- Conditions that preclude the cognitive testing (e.g. delirium, intubation, reduced vigilance
- Neurological or psychiatric conditions that preclude the data interpretation (e.g. pre-stroke dementia, schizophrenia, brain tumor, regular intake of benzodiazepine, depression)
- MRI contraindication
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Number of participants with delayed cognitive deterioration (DCD)
Time frame: at 3 months, at 12 months and at 36 months post-stroke
The investigators will assess number of participants with deterioration of the cognitive performance in ≥2 cognitive domains on ≥ 1 Standard Deviation (1 SD).
Number of participants with delayed functional deterioration
Time frame: at 3 months, at 12 months and at 36 months post-stroke
The investigators will assess number of participants with deterioration of functional disability will be defined as decrease in disability level to one point assessed via modified Rankin Scale (mRS, 0-6, whereas 0=no functional disability).
1 secondary outcome
Number of participants with post-stroke cognitive impairment
Time frame: 10 days post-stroke, 3 months, 12 months and at 36 months post-stroke
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 May 2026.
- Background: PubMed 28049565Umarova RM. Adapting the concepts of brain and cognitive reserve to post-stroke cognitive deficits: Implications for understanding neglect. Cortex. 2017 Dec;97:327-338. doi: 10.1016/j.cortex.2016.12.006. Epub 2016 Dec 16.
- Derived from this study: PubMed 39209968Gallucci L, Sperber C, Monsch AU, Kloppel S, Arnold M, Umarova RM. Improving diagnostic accuracy of the Montreal Cognitive Assessment to identify post-stroke cognitive impairment. Sci Rep. 2024 Aug 29;14(1):20125. doi: 10.1038/s41598-024-71184-x.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Roza M. Umarova, PD Dr. principal investigator
Department of Neurology, Inselspital, University Hospital Bern, University of Bern
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of First-ever Ischemic Stroke and Cognitive Performance, run by Roza Umarova at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 6 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Roza M. Umarova, PD Dr. (+41316327000, roza.umarova@insel.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with delayed cognitive deterioration (DCD) (time frame: at 3 months, at 12 months and at 36 months post-stroke). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05653141, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 May 2026.