Background and Purpose: Sleep apnea (SA) is emerging as a risk factor of stroke, and stroke itself can also influence the sleep. However, investigation of SA in acute ischemic stroke is scanty. We evaluated the prevalence of SA in early stage of stroke and analyzed the SA degree and ischemic stroke subtypes and severity.
Methods: We prospectively performed overnight polysomnography (PSG) in consecutive acute ischemic stroke patients who were admitted to the stroke unit within 72 hours from onset. PSG was performed on the first night, and severe stroke patients who could not stand the PSG were excluded. The apnea-hypopnea index (AHI) was calculated using the total number of apneas and hypopneas per hour sleep, and categorized into mild (AHI 5-14/hour), moderate (15-29), and severe (≥ 30). Ordinal logistic regression was performed to predict the factor associated with severity of SA (no, mild, moderate and severe).
Results: From Aug 2015 to March 2016, a total of 141 patients were enrolled: mean age 63.5 ± 13.3 years, 69.5% male, median (IQR) NIHSS 3 (1-6). Among them, 124 (87.9%) patients had SA (AHI ≥ 5/hour) of any degree: 41.1% mild, 21.8% moderate, and 37.1% severe. Higher NIH stroke scale was associated with SA severity (p = 0.010). According to the stroke subtype by TOAST classification, cardioembolism was associated with more severe SA (p = 0.043).
Conclusion: SA is frequently found in acute phase of ischemic stroke. Higher degree of SA is associated with severe stroke and cardioembolic etiology.