Posted on May 06, 2009, 10 a.m.
By gary clark
Stroke victims who also suffer from sleep apnea, the common breathing disorder that affects sleep quality, are at a higher risk of death within the first month following a stroke – and they are more disabled following discharge from the hospital – a stroke-sleep study finds.
Scientists have long known that sleep apnea, a breathing disorder that is associated with the collapse of the pharyngeal airway and can cause dangerous blood pressure fluctuations - is linked to many types of cardiovascular conditions. Now researchers from the University of Rochester Medical Center have found that sleep apnea also leads to a poorer prognosis in stroke victims. Working in collaboration with sleep apnea expert Dr. Virend Somers, the investigators used a standard questionnaire to assess the risk of sleep apnea in 174 patients who were diagnosed with acute ischemic stroke in the emergency department of Mayo Clinic between June 2007 and March 2008. In some cases, the partners of the study participants helped provide information. Of the patients, 60 percent were found to be at high risk for obstructive sleep apnea - and all seven of those who were previously diagnosed with sleep apnea had a higher risk of death within the first month following their stroke. Moreover, after the researchers adjusted the results for age and stroke severity, they found that patients with diagnosed or undiagnosed sleep apnea were more disabled at the time of discharge, concluding that "a high risk of obstructive sleep apnea was a predictor of having a worse outcome."
"We know that obstructive sleep apnea has been linked to a multitude of cardiovascular problems, yet it is concerning that the vast majority of cases remain undiagnosed," says Latha Stead, M.D., professor and chair of the Department of Emergency Medicine at the University of Rochester Medical Center. "In the context of recovering from a stroke, sleep apnea can have a serious impact, and for that reason we encourage people to become more aware of obstructive sleep apnea and to get treatment," she adds. The findings were reported at the recent annual meeting of the American Academy of Neurology held in Seattle, WA.
While the reason for the association between sleep apnea and poorer outcomes following a stroke is not exactly known, Stead surmises that since blood is not properly oxygenated during a sleep cycle disrupted by sleep apnea, it is more difficult for the brain and related tissue affected by a stroke to heal. "The important message is that in the Emergency Department setting, it's critical to investigate all of the known risk factors that indicate a poor prognosis following a stroke," Stead emphasizes. "The next step is to begin routine screening for obstructive sleep apnea as part of the emergency department evaluation of stroke patients," she notes.
News Release: Poor sleep quality leads to poorer prognosis after stroke www.eurekalert.org April 28, 2009