Enlarged Perivascular Space and Its Correlation with Polysomnography Indicators of Obstructive Sleep Apnea

There is increasing evidence of a causal interaction between obstructive sleep apnea (OSA) and white matter hyperintensity (WMH). WMH and enlarged perivascular space (EPVS) are the neuroimaging markers for cerebral small vessel disease (CSVD). Thus, this study aimed to determine whether a contextual relationship existed between OSA and EPVS.

In this study, 107 participants underwent 1-night polysomnography, brain magnetic resonance imaging (MRI) and health screening examinations and were classified as 63 OSA patients (mild, moderate, and severe groups), and 44 healthy controls. We assessed the sleep characteristics in OSA group, quantified the total EPVS from MRI and related them to the measures of polysomnography-obtained sleep parameters.

Polysomnography revealed that 63 OSA patients had sleep architecture alteration. A higher proportion of N2 phase sleep (N2%), lower percentage of N3 sleep (N3%) and REM sleep (REM%), as well as increased arousal index (AI), oxygen desaturation index (ODI) and decreased lowest arterial oxygen saturation (LSaO2) were detected. The results also indicated a higher prevalence and a larger number of EPVS, and a lower Mini Mental State Scale (MMSE) scale score in OSA group. LSaO2, N3% and REM% were negatively correlated with the total EPVS, whereas ODI, AI and N2% were positively correlated with the total EPVS.

The findings suggested that OSA patients had sleep disturbances with a higher incidence and more severe EPVS. Furthermore, the EPVS in OSA might be secondary to sleep disturbances, intermittent hypoxemia and the respiratory event-related hemodynamic changes. Thus, our findings highlighted that increased risk for EPVS in OSA is a potential contributor to increased stroke risk in OSA.