Verstraeten Edwin, Cluydts Raymond, Pevernagie Dirk, Hoffmann Guy
Department of Cognitive and Physiological Psychology, Lab for CAS Research: Cognition, Neuropsychology & Sleep, Vrije Universiteit/Free University Brussels, Belgium.
Sleep. 2004 Jun 15;27(4):685-93.
As the effects of general slowness and decreased attentional capacity on higher executive attention have not been fully taken into account in the sleep apnea literature, we statistically controlled for basic attentional performance in evaluating executive attention per se in sleep apnea patients.
A case-controlled design was used with comparison of basic and executive attentional tasks.
Thirty-six polysomnographically diagnosed patients (mean apnea-hypopnea index = 60.5 +/- SD 31.6) participated, together with 32 healthy controls.
Neuropsychological tests included Trail Making part A and B, Symbol Digit Modalities (SDMT), Digit Span forward and backward, Stroop Color-Word, Five-Point design fluency, and an Attentional Flexibility task. Patients' vigilance data indicated time-on-task decrements after 10 minutes. Moreover, their performance was significantly reduced on the SDMT (effect size d = 0.93), the Digit Span forward task (d = 0.44), the number of errors on the basic 2-choice reaction time subtest of the Attentional Flexibility task (d = 0.74) and the mean RT on the actual Attentional Flexibility subtest (d = 0.54). It has been argued that the latter poor performance was probably primarily related to the task's phonologic loop component of working memory rather than to an attentional switching deficit per se. No other performance differences were found between patients and healthy controls.
In addition to vigilance decrements, attentional capacity deficits clearly emerge, ie, slowed information processing and decreased short-term memory span. However, no specific clinical indications for executive attentional deficits--such as disinhibition, distractibility, perseveration, attentional switching dysfunction, decreased design fluency, or an impaired central executive of working memory--are found in patients with severe sleep apnea. Their cognitive performance seems very similar to the cognitive decline found after sleep loss and qualitatively different from patients with chronic obstructive pulmonary disease, suggesting sleepiness as the primary factor in a parsimonious explanation for the attention deficits in sleep apnea, without the need to assume prefrontal brain damage.
由于睡眠呼吸暂停文献中尚未充分考虑一般反应迟缓及注意力容量下降对高级执行性注意力的影响，我们在评估睡眠呼吸暂停患者的执行性注意力本身时，对基本注意力表现进行了统计学控制。
采用病例对照设计，比较基本注意力任务和执行性注意力任务。
36例经多导睡眠图诊断的患者（平均呼吸暂停低通气指数=60.5±标准差31.6）参与研究，另有32名健康对照者。
神经心理学测试包括连线测验A和B、符号数字模式测验（SDMT）、顺背和倒背数字广度、斯特鲁普颜色-文字测验、五点设计流畅性测验以及注意力灵活性任务。患者的警觉性数据显示，任务进行10分钟后，任务持续时间减少。此外，他们在SDMT（效应量d=0.93）、顺背数字广度任务（d=0.44）、注意力灵活性任务的基本二选一反应时子测验中的错误数量（d=0.74）以及实际注意力灵活性子测验中的平均反应时（d=0.54）上的表现显著降低。有人认为，后者表现不佳可能主要与任务工作记忆的语音回路成分有关，而非注意力转换缺陷本身。患者与健康对照者之间未发现其他表现差异。
除警觉性下降外，注意力容量缺陷明显出现，即信息处理速度减慢和短期记忆跨度减小。然而，在重度睡眠呼吸暂停患者中未发现执行性注意力缺陷的特定临床指征，如去抑制、易分心、持续动作、注意力转换功能障碍、设计流畅性降低或工作记忆的中央执行功能受损。他们的认知表现似乎与睡眠剥夺后发现的认知衰退非常相似，且在性质上与慢性阻塞性肺疾病患者不同，这表明嗜睡是对睡眠呼吸暂停注意力缺陷进行简洁解释的主要因素，无需假设存在前额叶脑损伤。
