阻塞型睡眠呼吸中止症患者的額葉功能與事件相關電位的探討

阻塞型睡眠呼吸中止症(Obstructive sleep apnea/hypopnea, OSAH)患者因夜間睡眠時上呼吸道反覆阻塞，導致呼吸中止、睡眠不連續及血中氧氣飽和度下降。臨床上，OSAH患者常出現日間過度嗜睡、警覺性與注意力的降低，甚至有認知功能的損傷。本研究藉完整的額葉功能評估及事件相關電位(P300)配合多頻道睡眠檢查(polysomnography, PSG)，探討OSAH患者額葉功能、P300之表現、兩者的相關性及其致病機轉。本研究收集了22名經PSG確定為OSAH的患者(男：女=17：5;平均年齡為51.0±11.1歲)與27名控制組(男：女=14：13; 平均年齡為56.0±7.8歲)，均接受額葉功能測驗、P300檢查與自評量表。相較於控制組，OSAH患者的部分額葉功能有顯著降低。OSAH患者P300之Pz與Oz振幅呈現顯著降低；潛時雖較正常組延長，但並無統計學上的顯著差異。此外，OSAH患者在Epworth嗜睡量表有較高得分，其差異也達顯著意義。P300的潛時與部分的額葉功能測驗變項間存在有顯著相關。PSG結果顯示睡眠結構的變化與額葉認知功能有顯著性相關。本研究發現1) OSAH患者具額葉功能缺損，2) 與智能相關之P300 於OSAH患者呈現顯著異常，3) OSAH患者之額葉功能表現與P300潛時具相關性，4) OSAH患者的認知功能缺損，可能是由於睡眠結構的異常所造成的。

關鍵字

阻塞型睡眠呼吸中止症；額葉功能；事件相關電位

並列摘要

Patients with obstructive sleep apnea/hypopnea (OSAH) which leads to the repeated cessation of breathing, sleep fragmentation, and oxygen desaturation during sleep, often complain excessive daytime sleepiness, vigilance alteration, and cognitive decline. Using comprehensive Frontal Test Battery and event-related potentials (P300), the aims of this study are 1) to evaluate the subtypes of frontal dysfunction, 2) to investigate the effect of P300, and 3) to clarify the possible mechanism of cognitive dysfunction in patients with OSAH syndrome. 22 OSAH patients, based on polysomnography (PSG) (M/F: 17/5, mean age: 51.0 ± 11.1 years) and 27 normal controls (M/F: 14/13, mean age: 56.0 ± 7.8 years) underwent comprehensive Frontal Test Battery and P300 assessments. In comparison with controls, the OSAH patients showed significant impairment in the ‘higher-level’ cognition and significant decreased amplitude in Pz and Oz recordings. In OSAH patients, there was significant negative correlation between high executive function and P300 latency. Furthermore, attention and memory were correlated with sleep architecture in OSAH patients. We conclude that the OSAH patients may manifest with significant ‘high-level’ frontal dysfunction and P300 amplitude decrement. There is a good correlation between executive dysfunction and P300 latency. We suggest that the cognitive impairment might be due to change of sleep architecture in OSAH patients.