Association between diabetes mellitus and post‐stroke cognitive impairment

Stroke survivors suffer from various physical, emotional, and cognitive impairments. These changes are dynamic and depend on multiple factors, including underlying diseases, baseline brain function and pathology, the site of the stroke and the post‐stroke inflammation, neurogenesis as well as the subsequent remodeling of the neuro‐network. First we review the structural and pathological changes of the brain in stroke survivors with diabetes mellitus, which may lead to post‐stroke cognitive dysfunction. Second, we provide evidence of hyperglycemia, diabetes mellitus, hypoglycemia, and their relationship with post‐stroke cognitive impairment (PSCI) and post‐stroke dementia (PSD). In addition to conventional biomarkers, such as HbA1c, we also provide other novel tools to predict PSCI/PSD, such as glycemic variability, receptor for advanced glycation end products, and gut microbiota. Finally, we attempt to provide some modifying methods for glycemic control, focusing on the prevention of PSCI/PSD. PSD and PSCI impose heavy burdens on patients, families, and society. However, cognitive function after stroke is dynamic and dysfunction is often overlooked. Impaired fasting glucose, prediabetes, type 2 DM, hypoglycemia, and glycemic variability may lead to cognitive dysfunction after stroke via various mechanisms and pathways. There is emerging evidence regarding the association between different DM medications and cognitive functions. However, their relationship with the PSCI/PSD warrants further investigation.