持续气道正压治疗对阻塞性睡眠呼吸暂停综合征脑电频谱的影响

目的　通过对有效持续气道正压 (CPAP)治疗前和治疗中阻塞性睡眠呼吸暂停综合征(OSAS)患者的睡眠脑电功率谱进行分析 ,了解CPAP治疗对大脑电活动的影响。方法　 2 6例OSAS患者均经多导睡眠图 (PSG)监测确诊。通过快速傅立叶转换 ,计算C3 /A2 导联脑电图的边缘频率 (SEF)、中心频率 (MPF)、α、β、δ、θ指数 ,比较治疗前和CPAP治疗中睡眠结构以及上述参数的变化。 结果　经CPAP治疗可以显著降低睡眠中的睡眠呼吸紊乱指数和改善睡眠结构。慢波睡眠的缺乏比率由 19/ 2 6降为 10 / 2 6 (P =0 0 2 5 )。快速动眼睡眠 (REM)次数由 1 81± 0 2 5增至 2 6 5± 0 17(P =0 0 2 3) ;慢性睡眠占总睡眠时间 (TST)的比率由 (2 9± 1 1) %增至 (6 0± 1 2 ) % ,(P =0 0 43)。REM占TST的比率由(12 0± 1 7) %增至 (2 1 1± 1 6 ) % (P =0 0 0 1) ;Ⅰ、Ⅱ期睡眠占TST的比率由 (85 1± 2 1) %降至 (73 0± 1 9) % ,(P =0 0 ) ;入睡后清醒次数由 (12 2± 1 3)次降为 (9 4± 1 0 )次 (P =0 0 33)。Ⅰ、Ⅱ期浅睡眠次数由 (4 6 4± 4 2 )次降为 (36 7± 2 4)次 ,Ⅰ、Ⅱ期睡眠次数比较差异无显著性 (P =0 0 5 1)。总睡眠期、Ⅰ、Ⅱ期、REM睡眠的平均SEF分别从 (14 4± 0 4)Hz、(15 4± 0 4)Hz、(13 7±

Electroencephalogram spectral power analysis of obstructive sleep apnea syndrome patients before and during continuous positive airway pressure therapy

OBJECTIVE: To investigate the instant effects of continuous positive airway pressure (CPAP) on EEG spectral power changes in obstructive sleep apnea syndrome (OSAS) patients. METHODS: 26 OSAS patients were included. The diagnosis was made by polysomnography (PSG). The CPAP pressure was titrated during the first night of therapy. During another night in two weeks after the diagnostic study, the patients accepted the whole night CPAP treatment while PSG was monitored. C(3)/A(2) was analyzed by using fast fourier transform (FFT). Spectral edge frequency (SEF), median power frequency (MPF), alpha index, beta index, delta index and theta; index during CPAP therapy were compared with those parameters before treatment. RESULTS: Sleep architecture was improved significantly during therapy. The ratio of slow wave sleep (SWS) deficiency reduced from 19/26 to 10/26 (P = 0.0250). There were more times of REM sleep (1.81 +/- 0.25) vs (2.65 +/- 0.17) (P = 0.023). A significant increase of total SWS time over total sleep time (TST) (2.9 +/- 1.1)% vs (6.0 +/- 1.2)% (P = 0.043) was observed, as well as total REM sleep time over TST (12.0 +/- 1.7)% vs (21.1 +/- 1.6)% (P = 0.001). Total stage I and stage II time over TST reduced greatly [from (85.1 +/- 2.1)% to (73.0 +/- 1.9)% (P = 0.000)]. So did the number of wake after sleep onset [from (12.2 +/- 1.3) to (9.4 +/- 1.0) (P = 0.033). The total number of stage I, stage II decreased from (46.4 +/- 4.2) to (36.7 +/- 2.4), but the difference was not significant (P = 0.051). Spectral analysis of EEG showed a decrease of mean SEF in total sleep period (TSP) (14.4 +/- 0.4) Hz vs (13.6 +/- 0.3) Hz (P = 0.003), stage I (15.4 +/- 0.4) Hz vs (14.8 +/- 0.5) Hz (P = 0.040), stage II (13.7 +/- 0.3) Hz vs (12.8 +/- 0.3) Hz (P = 0.007) and REM sleep (15.0 +/- 0.5) Hz vs (13.8 +/- 0.6) Hz (P = 0.028), as well as 0.018 and 0.047]. delta index was increased in stage II sleep (P = 0.030) but not in other sleep stages. CPAP had no obvious influence on theta; index (P > 0.05). The median of SEF in TSP (14 vs 13) Hz (P = 0.0056), stage I (16 vs 15) Hz (P = 0.04) and stage II (13 vs 13) Hz (P = 0.002). Changes of MPF were not as significant as that of SEF, but mean MPF was decreased during TSP and stage IV. CPAP significantly reduced mean beta index [from (8.4 +/- 0.5)% to (7.5 +/- 0.5)% (P = 0.012)] in total sleep period as well as in stage I, II, III and IV sleep (P < 0.015). alpha index in TSP, stage III and IV sleep was decreased significantly (P = 0.045, 0.018 and 0.047 respectively). delta index was increased in stage II sleep (P = 0.030) but not in other sleep stages. CPAP had no obvious influence on theta; index (P > 0.05). CONCLUSIONS: CPAP has an acute effect in improving the sleep architecture and EEG power spectrum. The SEF, beta index and alpha index are more sensitive than MPF, delta index and theta; index to CPAP therapy. These changes may be related to the recovery of cerebral function in OSAS patients after CPAP therapy. More studies need to be conducted to investigate how these changes happen and their relation to daytime cerebral function.