Original Article A silent pre-stroke damage: obstructive sleep apnea syndrome

Objectives: We investigated the prevalence of silent cerebro-vascular lesions and atrophy in patients with obstructive sleep apnea syndrome (OSAS) and the correlation between OSAS severity and prevalence of silent cerebrovascular lesions in Turkish patients. Methods: Study subjects were 56.35 OSAS, polysomnography (PSG)- confirmed patients who visited the sleep disorders clinic in our university hospital. None had a history of cerebrovas - cular disease (CVD). The control group consisted of normal subjects who had no history of snorring, apnea, exces- sive daytime sleepiness and had under 10 score of epworth sleepiness score. We performed a cross-sectional study on OSAS severity and the prevalence of silent cerebrovascular lesions and atrophy detected by brain MRI analysis. Results: The control group included 21 subjects, the moderate OSAS (AHI 15 to < 30/h) group included 7 patients with a mean AHI of 22.0 ± 5.3/h while the severe OSAS (AHI ≥ 30/h) group included 28 patients with a mean AHI of 60.0 ± 27.4/h. A larger percentage of patients with severe OSAS had a higher BMI than those with moderate OSAS and control subjects (P < 0.05). Silent ischemic gliotic lesions was identified in 10 (38.2%) control subjects, 27 (61.8%) with moderate and severe OSAS. Among control subjects and the moderate, and severe OSA groups, 10 (38.2%), 6 (85.7%) and 21 (77.7%) respectively, had periventricular hyperintensity (PVH); most PVH was mild to moderate. Conclusion: Results indicate that patients with moderate to severe (AHI ≥ 15/h) OSAS have a higher prevalence of silent cerebrovascular lesion than those with no OSAS.