β-Hydroxybutyrate improves glymphatic system function and alleviates cerebral edema in mice after ischemic stroke.

Cerebral edema is a severe complication following ischemic stroke. Recent studies have highlighted the crucial role of the glymphatic system (GS) in the clearance of water and macromolecules. GS dysfunction involving the disorders of AQP4 polarization may be crucial in the pathophysiology of cerebral edema. β-Hydroxybutyrate (BHB), the main component of the ketone body, has been shown to alleviate neurological deficits by restoring GS function in subarachnoid hemorrhage models and to reduce Aβ deposition in Alzheimer's disease models. In this study we investigated the effects of BHB on cerebral edema following ischemic stroke and its mechanisms. The mice were fed a ketogenic diet (KD) or a normal diet for 4 weeks before transient middle cerebral artery occlusion (MCAO). Alternatively, the mice received BHB (5 g·kg