Therapeutic effects of long-term continuous positive airway pressure treatment on improving leptomeningeal collateral circulation in obstructive sleep apnea syndrome patients.

OBJECTIVE: This study aims to use methods of scoring collaterals on CT angiography to analyze changes in collateral circulation in untreated patients with moderate and severe OSAS before and after nasal continuous positive airway pressure (CPAP) treatment.

PATIENTS AND METHODS: Ninety-eight moderate and severe OSAS patients treated with nasal CPAP and seventy-four controls that weren't treated with CPAP, were involved in this study. Two independent neuroradiologists evaluated intracranial collaterals by using Miteff scale, modified Tan scale. Intracranial collaterals differences were compared between OSAS group (before and after treated) and control group. Correlations between intracranial collaterals and clinical parameters were analyzed.

RESULTS: Compared with pre-therapy of moderate and severe groups, apnea-hypopnea index (AHI), oxygen desaturation index (ODI), epworth sleepness scale (ESS) were lower after treatment. The lowest oxygen saturation, average blood oxygen saturation, Miterff scale, modified Tan scale in moderate and severe groups were significantly increased after treatment. We documented significant decrease of Miterff scale after two years in moderate and severe OSAS group without CPAP therapy (n = 32, p < 0.01). Conversely, mild OSAS group without CPAP therapy did not change Miterff scale after two years (n = 32, p > 0.05). Multivariate Logistic regression analysis showed that AHI had significant impact on Miterff scale and modified Tan scale. Severe OSAS were independently related with Miterff scale (odds ratio 0.343, 95% confidence interval 0.301-0.391, p < 0.01) and modified Tan scale (odds ratio 0.267, 95% confidence interval 0.095-0.754, p = 0.013).

CONCLUSIONS: Long-term CPAP treatment is a viable therapeutic choice for improving leptomeningeal collateral circulation in OSAS patients.