RNA gene expression and cognitive reserve as determinants of post-ischaemic stroke cognitive recovery.

Cognitive impairment is a common yet under-recognised complication of ischaemic stroke (IS), with long-term effects on patient quality of life and rehabilitation outcomes. Identifying early biomarkers and protective factors such as cognitive reserve (CR) is essential for improving prognosis and guiding targeted interventions. This study aimed to determine the following: (i) RNA gene expression profiling during acute stroke and (ii) the associations between target genes as well as clinical factors and cognitive impairment during an acute event and at the 3-month follow-up. A three-month prospective cohort study involving 24 adults with mild to moderate IS and 24 age- and sex-matched controls admitted to Hospital Canselor Tuanku Muhriz, Malaysia, was conducted. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) within 48 h of stroke and at 3 months. Peripheral blood samples were collected for RNA extraction, and gene expression was analysed using RT² Profiler PCR arrays. Cognitive reserve was measured using the Cognitive Reserve Index Questionnaire (CRI-q). Statistical analyses included chi-square and independent t tests. At baseline, 83.3% of IS patients exhibited cognitive impairment (mean age 64.6 ± 10.5 years). Increased age (p = 0.006), low education level (p = 0.010), diabetes mellitus (p = 0.010), CRI-Education (p = 0.010) and CRI-Working Activity (p = 0.009) were significantly associated with baseline cognitive impairment. These clinical and CR factors survived False Discovery Rate (FDR) correction at the baseline stage (p < 0.05). However, at the 3-month follow-up, no clinical or CR factors remained statistically significant after FDR correction. Regarding gene expression, while MAPK1 (p = 0.029) and CAPZB (p = 0.042) were nominally upregulated in patients, and RCOR1 (p = 0.043) showed a nominal association with baseline impairment, no genetic markers survived FDR correction at either time point. Age, diabetes, and cognitive reserve are robust determinants of cognitive status during the acute phase of ischaemic stroke. The loss of significance at 3 months suggests these factors are primary drivers of initial functional buffering rather than long-term recovery trajectories in this cohort. CR should be utilised as a prognostic stratification tool during admission to identify high-risk patients rather than as a direct target for acute intervention. Future large-scale studies are required to validate whether the observed nominal gene expression trends can serve as reliable biomarkers for long-term recovery.