The research project was conducted in the Hôpitaux de Toulouse, France
Cerebral autoregulation in patients with obstructive sleep apnea syndrome during wakefulness
Article first published online: 19 JAN 2009
© 2009 The Author(s). Journal compilation © 2009 EFNS
European Journal of Neurology
Volume 16, Issue 3, pages 386–391, March 2009
How to Cite
Nasr, N., Traon, A. P.-L., Czosnyka, M., Tiberge, M., Schmidt, E. and Larrue, V. (2009), Cerebral autoregulation in patients with obstructive sleep apnea syndrome during wakefulness. European Journal of Neurology, 16: 386–391. doi: 10.1111/j.1468-1331.2008.02505.x
- Issue published online: 5 FEB 2009
- Article first published online: 19 JAN 2009
- Received 20 July 2008 Accepted 17 October 2008
- brain circulation and metabolism;
- cerebrovascular disease/stroke;
- Doppler ultrasound;
- sleep apnea;
- transcranial Doppler
Background and purpose: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for stroke. Impairment of cerebral autoregulation may play a potential role in the pre-disposition to stroke of OSAS patients. In this study, we aimed to assess dynamic cerebral autoregulation (DCA) during wakefulness in OSAS patients and a group of matched controls.
Methods: Patients and controls were examined in the morning after an overnight complete polysomnography. Mean cerebral blood flow velocity (CBFV) in the middle cerebral artery and mean arterial blood pressure (ABP) were continuously recorded using transcranial Doppler and Finapres. DCA was assessed using the Mx autoregulatory index. Mx is a moving correlation coefficient between mean CBFV and mean ABP. More positive value of Mx indicates worse autoregulation.
Results: Eleven OSAS patients (mean age ± SD; 52.6 ± 7.9) and 9 controls (mean age ± SD; 49.1 ± 5.3) were enrolled. The mean apnea–hypopnea index (AHI) in the OSAS group was of 22.7 ± 11.6. No significant difference was found between the two groups as for age, body mass index, mean ABP and endtidal CO2 pressure. Cerebral autoregulation was impaired in OSAS patients compared with controls (Mx index: 0.414 ± 0.138 vs. 0.233 ± 0.100; P = 0.009). The severity of autoregulation impairment correlated to the severity of the sleep respiratory disturbance measured by the AHI (P = 0.003).
Conclusion: Cerebral autoregulation is impaired in patients with OSAS during wakefulness. Impairment of cerebral autoregulation is correlated with the severity of OSAS.