Effects of Oxiracetam and Physical Activity in Preventing Post-Stroke Cognitive Decline: A Randomized Controlled Trial

This trial, conducted according to the request of the Korean Ministry of Food and Drug Safety, investigated the potential of oxiracetam in mitigating post-stroke cognitive decline, and whether physical activity could augment its efficacy. The mechanisms behind these effects were explored using functional neuroimaging. In this multicenter, randomized, double-blind, placebo-controlled trial, we enrolled patients reporting subjective cognitive decline more than three months post-stroke and at a high risk of dementia. Participants were randomly assigned to a 36-week regimen of either 800 mg oxiracetam or a placebo, administered twice daily, in conjunction with recommended physical activity. Physical activity levels were monitored using wrist actigraphy. Cognitive function was assessed using a mini-mental state examination (MMSE) and clinical dementia rating sum of boxes (CDR-SB) at baseline and 36 weeks. Other assessments included the 60-minute protocol of Vascular Cognitive Impairment Harmonization Standards, Euro QoL, patient's global assessment, and resting-state functional MRI-derived neural network attributes. Of the 500 participants (mean age 68.9 years, male 76.1%, median interval between stroke and randomization 32 months), 457 were analyzed. Both groups have equally adhered to the exercise guidelines (moderate-to-vigorous physical activity per day; 23.7±26.1 vs. 24.1±28.7 minutes; p=0.75). No significant difference was observed in changes to MMSE and CDR-SB scores between the two groups (MMSE, 0.13±2.27 vs. 0.27±2.09, p=0.49; CDR-SB -0.14±0.70 vs. -0.08±0.80, p=0.38). Although increased baseline exercise time correlated with better MMSE scores, the correlation was weak (R= 0.11, p=0.02). Verbal memory, phonemic fluency, language, NPI-Q, and geriatric depression scale also improved significantly within each group. However, only the intervention group showed significant improvements in CDR-SB and EuroQoL scores. A predetermined multivariate analysis showed a significant change in the normalized clustering coefficient for the secondary efficacy endpoint (r=0.09, SE=0.04, p=0.03). This study failed to confirm the efficacy of oxiracetam in preventing post-stroke cognitive decline. Nonetheless, adherence to the exercise guidelines appeared to help participants maintain their cognitive functions, despite being a chronic stage post-stroke and having a high dementia risk.