Cerebrospinal fluid influx drives acute ischemic tissue swelling

TLDR

The brain is surrounded by cerebrospinal fluid that normally protects and clears waste, and recent studies show CSF transport also influences neurodegeneration and sleep. In rodents, multimodal imaging revealed that stroke triggers arterial constrictions via spreading depolarization, causing a large CSF influx that swells the brain. The study shows that CSF influx after stroke contributes to brain swelling. Mestre et al., Science, this issue p.

Abstract

Spreading edema after stroke The brain is enveloped in a cushion of cerebrospinal fluid (CSF), which normally provides protection and helps to remove metabolic waste. CSF transport has also recently been shown to play unexpected roles in neurodegeneration and sleep. Mestre et al. used multimodal in vivo imaging in rodents and found that, after a stroke, an abnormally large volume of CSF rushes into the brain, causing swelling (see the Perspective by Moss and Williams). This influx of CSF is caused by constrictions of arteries triggered by a well-known propagating chemical reaction-diffusion wave called spreading depolarization. CSF transport can thus play a role in brain swelling after stroke. Science , this issue p. eaax7171 ; see also p. 1195