After a stroke, more time in bed may affect memory, experts reveal

A good night’s sleep is essential for health and emotional well-being. However, the same cannot be said for people who survived a stroke of transient ischemic attack (TIA). After a stroke or TIA, spending more time in bed, either sleeping or trying to sleep, may not be beneficial for cognitive function, reveals new research.

Sleep and brain function post stroke

According to a new study published in Neurology , added sleep duration is associated with poorer thinking and memory skills. To understand the link between sleep and brain function in individuals who suffered a stroke, the researchers studied 422 adults with an average age of 66 from Edinburgh and Hong Kong who had recently experienced a mild stroke or TIA. One to three months following the event, all participants underwent brain scans, were asked to complete sleep questionnaires, and take cognitive assessments.

They found that spending more time in bed was linked to lower scores on tests of thinking and memory skills and changes in their brains that can lead to dementia or a second stroke.

What is a stroke

A stroke occurs when blood flow to part of the brain is interrupted or reduced, depriving brain tissue of oxygen and nutrients. A transient ischemic attack (TIA), often referred to as a 'mini stroke,' involves a brief blockage of blood flow. While symptoms usually resolve within minutes or hours, a TIA can be an early warning sign of a more serious stroke.

Sleep after a stroke

The researchers observed that spending more time in bed does not equate to sleep. Difficulty falling asleep, fragmented sleep, poor quality sleep, or other problems are signs of a sleep disorder. The study found that both people with longer in-bed times and with longer sleep durations were more likely to have these brain changes.

The study, however, does not prove that these sleep issues cause these brain changes and thinking problems; it only shows an association.

What do experts think

Disturbed sleep is not great for health. “These results show that disturbed sleep may be a marker of adverse brain health, even for people with mild strokes or TIAs. While many people know that a lack of sleep can lead to health issues, less is known about the effects of sleeping longer at night or spending a long time in bed trying to make up for having trouble sleeping—whether people are doing this consciously or not,” study author Joanna M. Wardlaw, MD, of the University of Edinburgh in the United Kingdom said in a statement.
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In the study, the researchers found that people who spent a longer time in bed were more likely to have signs of damage to small blood vessels in the brain, including a greater volume of white matter hyperintensities, or areas in the white matter of the brain where brain tissue has been damaged. These participants were also more likely to have slightly lower scores on the test of thinking and memory skills.

People who had longer sleep duration were more likely to have small areas of microhemorrhages, or microbleeds, in the brain.

“More research is needed to confirm these findings and also to look at whether prolonged sleep has negative effects on people who have never had a stroke or TIA. Of course, research is also needed on whether improving people’s sleep patterns after stroke could ward off some of these possible detrimental effects,” Wardlaw added.