On top of several other associated risk factors, poor sleep could mean an increased risk of stroke, according to a new study review published in the journal Neurology.

The problems come especially when people experience sleep-disordered breathing (SDB) and sleep-wake disorders, researchers found. They gathered information from nearly 2,700 previous studies on sleep and neurology to perform a meta-analysis of the data.   

They found that more than 50 percent of stroke patients showed some kind of pre-stroke SDB and that the disordered tended to improve during stroke recovery. But when the disordered breathing and sleep-wake disorders persist during stroke recovery, they can hinder stroke recovery.

According to 29 studies of sleep-disordered breathing and stroke, the researchers found a pattern of the worst cases of SDB associated with acute stroke. And 53 percent of stroke patients still showed symptoms related to SDB four weeks post-stroke. The analysis of these study cohorts also showed that SDB could cause paradoxical embolism and an association between the disorder and brainstem stroke, researchers found. And a combination of two types of SDB—central sleep apnea and Cheyne-Stokes breathing—were associated with heart failure in chronic stroke patients.

They found that excessive sleep occurred mostly after acute stroke. They also found that insomnia prevalence among stroke patients might be as high as about 50 percent. And about 12 or 13 percent showed restless leg syndrome, with 11 percent of ischemic stroke patients showing REM sleep behavior disorder.

The researchers also looked at the relationship between stroke risk factors and these sleep disorders, including possible treatments such as sleeping aid drugs, CPAP machines and recommended weight loss.

The meta-analysis authors recommended more specific awareness of sleep disorders in stroke patients and as a risk factor for stroke. They recommended sleep treatments for patients post-stroke to improve stroke recovery and for patients before stroke who have other risk factors as a way to minimize their overall stroke risk.