Patients who experience an increase in brain swelling in the first 24 hours following a bleed, or brain haemorrhage, are more likely to have worse outcomes than those who don't, researchers found.
A similar risk was identified among those who experienced worsening swelling within 72 hours of diagnosis.
Early intervention to prevent swelling could potentially limit the severity of brain damage, leading to better recovery after stroke, experts say.
Brain bleed
Strokes occur when blood flow to part of the brain is either blocked by a clot or disrupted following a bleed, depriving brain tissue of oxygen and nutrients. Around 15 per cent of strokes are due to bleeding in the brain, known as a haemorrhagic stroke.
Swelling after a haemorrhagic stroke can increase pressure inside the skull, causing further harm to the brain. There are currently no treatments to reduce brain swelling.
A team of scientists, led by the University of Edinburgh, analysed data from more than 1500 people across nine different studies that measured levels of brain swelling in patients following a haemorrhagic stroke.
Worsening swelling
Researchers compared brain scans at diagnosis and after 24 and 72 hours, to examine changes in swelling volume. This was linked with reports of death or dependency at 90 days.
They found the likelihood of death or dependence increased by four per cent for each 1ml increase in swelling during the first 24 hours, and by two per cent for each 1ml of swelling in the 72 hours after onset.
Understanding the pathways and mechanisms that lead to brain swelling could help to identify potential drug targets, opening new possibilities for treatments, experts say.
A future trial, led by the same research team, will test potential drugs that could modify swelling during the early stages of brain heamorrhage, targeting inflammatory pathways which could enhance protective responses or inhibit harmful ones.
The study was funded by the Stroke Association and British Heart Foundation.