Brain Featured

Behind the Research: How at-home sleep tests can help diagnose sleep apnea in patients with stroke

Dr. Mark Boulos

Could a portable home sleep monitor one day be a tool to diagnose sleep apnea in routine clinical practice?

Dr. Mark Boulos, stroke neurologist and sleep expert, is among a team of Sunnybrook researchers who are exploring this in patients who have had a stroke or transient ischemic attack (TIA).

“To our knowledge, this is the first trial in the world to study stroke and TIA patients using a home sleep apnea test versus an in-laboratory sleep test, to assess which one is more effective for diagnosing obstructive sleep apnea,” says Dr. Boulos, study principal investigator, stroke neurologist, and sleep expert in Sunnybrook‘s Hurvitz Brain Sciences Program.

A transient ischemic attack or TIA happens when blood flow to the brain is temporarily interrupted. It can also be a warning sign of a future stroke. Often patients who have had a stroke or TIA experience sleep disorders, such as Obstructive Sleep Apnea (OSA), which happens when a patient’s breathing stops many times during sleep. This can lead to issues with thinking, memory, and other health concerns.

The results of this study have been published in the journal Stroke.

Dr. Boulos shares insight on the study findings and how they could benefit patients in the future.

What is your study looking at?

We know that in post-stroke/TIA patients, OSA is prevalent, but it is often underdiagnosed because patients may find having in-laboratory sleep testing to be inconvenient or uncomfortable. In-laboratory sleep testing is also quite expensive for the healthcare system. Our team wanted to investigate whether screening for OSA in these patients using at-home sleep apnea tests could increase diagnosis and treatment when compared to in-laboratory sleep tests.

What is an at-home sleep test and how does it work?

Home sleep apnea tests are devices that can be used when a person is sleeping to monitor breathing and oxygen levels. The monitoring kit includes sensors which go around your chest, a finger clip which tracks heart rate, and a nasal cannula or tube that measures airflow and oxygen. Past studies have demonstrated at-home sleep apnea devices can be as accurate as 95 per cent compared to in-laboratory sleep studies. 

Dr. Mark Bolous wears a sleep monitor

How was this studied?

We studied 250 patients with stroke or TIA. Half of the participants underwent the home sleep test and the other half, the in-laboratory sleep test. Patients completed assessments and questionnaires at baseline and during six-month follow-up appointments. Patients diagnosed with OSA were offered continuous positive airway pressure (CPAP) to manage symptoms.

What did the study find?

Our study demonstrated that in patients with stroke or TIA, those who used a home sleep apnea test were more likely to be diagnosed with OSA compared to those who underwent the in-laboratory sleep test (approximately 49 per cent compared to 35 per cent). The main reason for this was because many patients were unwilling or unable to be tested in the sleep laboratory.

Overall, there was an increase in OSA diagnosis and treatment, reduced daytime sleepiness and improved functional outcomes. In-home sleep apnea testing was also demonstrated to be a cost-effective approach for the diagnosis of OSA compared to the in-laboratory sleep test.

Dr. Mark Bolous wears a sleep monitor

What does it mean for patients?

In our study, significantly more patients had a positive experience with sleep testing after undergoing a home sleep apnea test compared to after undergoing an in-laboratory sleep test.

Use of an ambulatory approach (such as a home-based sleep test) to diagnose sleep apnea may improve clinical outcomes such as daytime sleepiness and functional outcomes, while also improving patients’ experiences with sleep testing.

How will these findings help clinicians?

This study provides clinicians with an alternative approach to diagnose sleep apnea, which may ultimately improve functional outcomes, improve patient’s experiences with sleep testing, as well as serve as a cost-effective approach for the diagnosis of sleep apnea. It could one day lead to home-based approaches for the diagnosis of sleep apnea and other neurological conditions.

Read the full study in Stroke »