Cognitive Impairments, COVID 19, Oxydative Stress
Conditions
Keywords
COVID 19, cell-free DNA, Neutrophil Extracellular Trap, AOPP, memory, attention
Brief summary
This observational cohort study will investigate the association between oxidative stress biomarkers and post-COVID-19 cognitive impairment. A total of 45 recovered COVID-19 patients aged 30-65 will be enrolled and followed at three intervals: 0-3, 3-6, and 6-12 months post-infection. Cognitive function will be assessed using standardized memory and attention tests, while venous blood samples will be analyzed for nitric oxide, AOPP, NETs, and extracellular nucleic acids. The study aims to identify early predictors of long COVID cognitive sequelae and evaluate biological mechanisms underlying persistent neurocognitive symptoms.
Detailed description
This prospective observational cohort study will aim to investigate whether markers of oxidative stress, including advanced oxidation protein products (AOPP), nitric oxide (NO), extracellular nucleic acids (DNA/RNA), and neutrophil extracellular traps (NETs), can predict cognitive dysfunction in patients recovering from COVID-19 pneumonia. Post-viral cognitive impairment, commonly referred to as brain fog, has emerged as a major complication in long COVID patients. The estimated prevalence of neurocognitive deficits ranges from 21% to 65% depending on disease severity and follow-up duration . Even individuals with mild infection can present with persistent impairments in memory, attention, and executive function . Growing evidence suggests that oxidative stress plays a critical role in neurodegeneration and long-COVID symptoms . SARS-CoV-2 triggers an oxidative storm, marked by excess production of reactive oxygen and nitrogen species, causing cellular injury . These species impair neurovascular coupling and lead to persistent endothelial dysfunction and neuroinflammation . Furthermore, cell-free DNA and RNA, key damage-associated molecular patterns (DAMPs), act as immune triggers via Toll-like receptor pathways . Another mechanism under scrutiny is NETosis, the extrusion of web-like neutrophil traps that damage endothelial cells, increase blood-brain barrier permeability, and drive systemic inflammation . Elevated NETs have been found in acute and chronic COVID-19 cases and may be a biomarker of persistent inflammation and thrombosis . Despite the biological plausibility of these mechanisms, there is limited longitudinal human data linking oxidative stress markers to cognitive outcomes in COVID-19 survivors. This study will follow participants for one year, evaluating neurocognitive performance and biochemical markers at three post-infection intervals: 0-3, 3-6, and 6-12 months.
Interventions
OTHERStandard Post-COVID Rehabilitation Program
This standardized rehabilitation intervention includes a 14-day inpatient course comprising physiotherapy, therapeutic exercises, massage, and respiratory gymnastics. The program is delivered equally to all participants regardless of cognitive status and is intended to promote post-viral recovery in patients recently discharged following COVID-19 pneumonia. No specific cognitive therapy or pharmacological treatment is administered during the rehabilitation period. The intervention is used as background care, not as an experimental variable.
Sponsors
Karaganda Medical University
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age \> 18 years * Confirmed history of COVID-19 pneumonia (PCR and CT-verified) * Recovered and discharged from COVID-19 hospital unit * Able to provide informed consent * Either presence or absence of self-reported cognitive complaints
Exclusion criteria
* History of CNS disease (e.g., dementia, stroke, TBI) * Psychiatric illness * Decompensated comorbidities (diabetes, cardiovascular, renal, or hepatic failure) * Alcohol/drug abuse * Uncontrolled hypertension * Acute respiratory insufficiency or fever at time of assessment
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Wechsler Memory Scale (WMS) Scores | Measured at 0-3, 3-6, and 6-12 months after discharge. | Assessment of memory function using the Wechsler Memory Scale, which measures different memory domains including working memory, visual memory, and auditory memory. Scoring Range: 50 to 150 (higher scores indicate better memory performance). |
| Change in Bourdon Attention Test Scores | Measured at 0-3, 3-6, and 6-12 months after discharge. | Assessment of sustained attention and processing speed using the Bourdon Attention Test, which records the number of correctly marked target symbols within a given time. Scoring Range: 0 to 15 (higher scores indicate better attention and processing accuracy). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Levels of Nitric Oxide (NO), AOPP, and Oxidised Proteins | Measured at 0-3, 3-6, and 6-12 months after discharge. | Measured via blood analysis at three time points. |
| Extracellular DNA/RNA and CRF nucleic acids | Measured at 0-3, 3-6, and 6-12 months after discharge. | Quantified in plasma and erythrocytes. |
| Neutrophil Extracellular Trap (NET) Levels | Measured at 0-3, 3-6, and 6-12 months after discharge. | Expressed as % of neutrophils, visualised microscopically. |
Countries
Kazakhstan
Outcome results
None listed