Researchers Devise Simple, Fast Method to Diagnose Sleep Disorders Among Stroke Survivors

Do strokes and disordered breathing during sleeping go hand-in-hand? Yes, according to BUSM researchers. Upper-airway obstruction occurring during sleep—or sleep-disordered breathing is common in stroke patients. These patients don’t recover as quickly and are more likely to die or have a recurrent stroke, especially among nonwhite racial and ethnic populations. The American Heart Association/American Stroke Association guidelines recommend considering sleep studies in patients with acute stroke and transient ischemic attack. However, screening is rare after stroke and outpatient sleep study testing (polysomnography) may take weeks or months to perform.

Now the BUSM researchers in a new study, have found that while most stroke patients have an undiagnosed sleep disorder called sleep apnea, (a serious disorder that can contribute to dangerous increases in blood pressure and increases risk of cardiovascular disease, like heart attack and stroke), their hospital-based screening and testing method correctly identified most patients with mild or worse sleep apnea.

“Our study underscores how common sleep apnea is among stroke patients, as approximately 80 percent of our patients had at least mild and almost 50 percent had moderate or severe, sleep apnea. We showed that screening our patients and using a portable sleep testing device during admission resulted in an early diagnosis for this treatable disorder,” explained corresponding author Hugo J. Aparicio, MD, MPH, assistant professor of neurology and an investigator at the Framingham Heart Study.

The researchers screened for sleep apnea during a quality improvement study conducted at Boston Medical Center (BMC). They compared the use of three questionnaires (STOP-BANG, Berlin Questionnaire and the Epworth Sleepiness Scale) that screen for sleep-disordered breathing to a diagnosis made using a portable sleep study testing device that patients wore overnight in the hospital.

They observed that one questionnaire, STOP-BANG, was easy to administer, brief and had good sensitivity for screening stroke patients for this disorder. “In addition, the portable sleep testing device results were highly consistent with the gold standard testing with outpatient polysomnography, and we were able to diagnose the disorder early after the stroke, where interventions were most likely to occur, such as referral to a sleep medicine specialist,” said Aparicio, who also serves as a neurologist at BMC.

According to the researchers, if medical providers can diagnose sleep apnea during admission for stroke, patients can then subsequently be referred to a sleep medicine specialist and be treated through interventions such as improved sleep hygiene, devices like a CPAP (continuous positive airway pressure) machine, or even surgery.

The researchers believe it is important for everyone, not just stroke patients, to know about the common signs and symptoms of sleep apnea including loud snoring, often feeling tired or fatigued during the day, witnessed apneas (when someone stops breathing during sleep), difficult to treat high blood pressure, and morning headaches. “While the disorder occurs more commonly among overweight and obese individuals and among persons with a history of stroke or heart attack, it is under-recognized and underdiagnosed in the general population as well.”

These findings appear online in the Journal of Clinical Medicine.

Funding for this study was provided by Boston University’s Spivack Neurosciences Program and Aram V. Chobanian Assistant Professorship and from the National Institute of Neurological Disorders and Stroke (L30 NS093634).