Obstructive Sleep Apnea and Stroke
Ischemic stroke (or acute stroke) is the second leading cause of long-term disability. Many who suffer from ischemic stroke also have obstructive sleep apnea (OSA). Currently, ischemic stroke treatment therapies have a very limited therapeutic window and are not widely applicable to most patients. The treatment of OSA in patients with acute ischemic stroke is now being looked to as a novel, therapeutic approach to preventing stroke.
Pathogenesis of Sleep Apnea
According to a paper published in the American Journal of Respiratory and Critical Care Medicine, “Central sleep apnea is generally the product of an unstable ventilatory control system (high loop gain) with increased controller gain (high hypercapnic responsiveness) generally being the cause.” OSA is generally caused by physiologic characteristics, primarily those that impact the airway and is considered to be a risk factor for stroke. Central sleep apnea may be a consequence of stroke, or a cause in the elderly.
Linking Sleep Apnea to Stroke
As mentioned in the 2019 AAST Annual Course presentation, “Obstructive Sleep Apnea and Stroke: Evidence, Mechanisms, and Treatment Strategies,” due to sleep inconstancies during the night, patients with OSA appear to be at a greater risk for developing diurnal (daytime) hypertension. Those with an increased severity of sleep apnea have an increased risk of developing hypertension. Patients with moderate to severe sleep apnea are at a greater risk (two to three times more likely) for developing hypertension over time. Hypertension is the most prevalent risk factor for stroke.
Consequences of Sleep Apnea
In addition to an increased risk of developing hypertension, patients with sleep apnea are susceptible to:
- Neuro-cognitive dysfunction
- Drowsiness-related accidents
- Cardiovascular and metabolic morbidity and mortality
According to the American Heart Association’s 2017 statistics report on heart disease and stroke, stroke is the second leading cause of death worldwide and the third leading cause of death in the United States. In the United States alone, strokes cost an estimated $34 billion each year, which includes the cost of acute and chronic health care services, medications, and missed days of productivity.
To learn more about OSA and stroke, view the full article in the 2020 Q4 issue of A2Zzz.