The parts of the brain that modulate breathing during sleep can become damaged by a stroke. New research sheds light on how sleep testing can better reach stroke patients.
By Lisa Spear
Once a person has experienced a stroke, they have a much higher chance of having sleep-disordered breathing. This is likely due to brain damage, especially from strokes that occur in the back of the brain, in the brainstem, which regulates breathing and nerve function to the airways.
“Strokes in the back of the brain can actually weaken the airway and make the airway more susceptible to collapse,” says Mark Boulos, MD, MSc, University of Toronto assistant professor and staff neurologist at Sunnybrook Health Sciences Centre.
Despite a high risk of obstructive sleep apnea (OSA), not all stroke patients are able to receive the gold standard in sleep diagnostic testing, in-lab polysomnography (PSG), for reasons that stem from the cost of the test to wanting to avoid the discomfort of an overnight stay in a sleep lab.
Many patients might find the in-lab test so inconvenient that they decide to skip it altogether.“Patients really don’t like in-laboratory sleep studies,” says Boulos.
For those stroke or transient ischemic attack (TIA) patients who don’t want or who can’t travel to have an in-lab sleep test, home sleep apnea tests (HSAT) could provide a cost-effective solution to reach as many patients as possible, according to a new research abstract that was published in the abstract supplement for the now cancelled 2020 annual meeting of the American Academy of Neurology (AAN).1 The research, coauthored by Boulos, found that when HSATs are deployed, more stroke patients are diagnosed with OSA. As a result, more of these patients are treated appropriately for their sleep-disordered breathing and experience less daytime sleepiness.
According to Boulos, an AAN member, the results are particularly important because if a stroke patient experiences OSA, they are more likely to have many other associated adverse health outcomes.
People who have sleep apnea following a stroke have a higher chance of having another stroke and have a higher chance of dying.2 These patients experience declines in quality of life and they are more sleepy. “There are all these super negative consequences of having sleep apnea after stroke, and not only is it bad, it is also very prevalent,” says Boulos.
About 50% to 70% of patients will have sleep apnea after a stroke, according to research funded by The National Institutes of Health.3
To compare in-lab with home sleep studies, Boulos and his colleagues recruited 250 patients who had a stroke or transient ischemic attack within the past 6 months. These patients had primarily come from stroke clinics and a stroke hospital ward and none of them had a prior diagnosis of sleep apnea.
The researchers randomized the patients to the use of HSATs versus in-laboratory PSGs.
They found a higher percentage of the group assigned HSATs actually complied with having a sleep study done, whereas fewer people in the in-lab PSG group were willing to follow through. “Patients were essentially saying ‘I don’t really want to bother using this [PSG] test, it is so inconvenient,’” Boulos says.
“Patients just like using home sleep tests so much more. And ultimately what happened is that we found in the home sleep testing arm, compared to the in-lab testing arm, more people were diagnosed with sleep apnea, not because this is a better diagnostic tool, but because more people, simply, used it.”
As a result, more patients screened with home sleep studies received CPAP and these patients experienced an increase in performance of daytime activities after 6 months.
There are also monetary benefits to opting for HSATs. The researchers conducted a cost analysis and found that these home-based solutions are more cost-effective for diagnosing sleep apnea compared to in-lab tests. According to the abstract, a home-based approach to OSA detection may also improve outcomes and reduce expenses in other clinical populations.
Lisa Spear is associate editor of Sleep Review.
1. Boulos M, Kamra M, Colelli D, et al. Screening for obstructive sleep apnea in stroke and TIA patients using a home sleep apnea test vs. In-laboratory polysomnography: A randomized controlled trial. Neurology. 2020 April 14;94(15 Suppl):2040.
2. Davis AP, Billings ME, Longstreth WT Jr, Khot SP. Early diagnosis and treatment of obstructive sleep apnea after stroke: Are we neglecting a modifiable stroke risk factor? Neurol Clin Pract. 2013 Jun;3(3):192-201.
3. Hermann DM, Bassetti CL. Sleep-related breathing and sleep-wake disturbances in ischemic stroke. Neurology 2009;73:1313–22.