Department of Neurology, Korea University College of Medicine, Seongbuk-Gu, Seoul, South Korea.
Sleep Med. 2011 Apr;12(4):416-21. doi: 10.1016/j.sleep.2010.08.018. Epub 2011 Mar 5.
It has been reported that patients with restless legs syndrome (RLS) may have cognitive deficit. The authors performed EEG and ERP analysis during daytime to identify electrophysiologic relations with cognitive dysfunction in unmedicated RLS patients.
Seventeen drug naive RLS patients (53.7±9.6 years) and 13 age-matched healthy controls participated in the present study. EEG was recorded during the waking-resting state and during a visual oddball task. RLS severities were determined using the International RLS Severity Scale. Stanford sleepiness scale (SSS) and bothersomeness visual analog scale (VAS) scores were determined immediately after ERP sessions. EEG power spectra and P300 amplitude and latency were compared for patients and controls. Clinical variables were correlated with P300 findings.
Waking-resting EEG showed that RLS patients had significantly higher beta activity in frontocentral regions than controls. SSS scores were not different in the two groups. But the bothersomeness VAS scores of RLS patients were significantly higher than those of controls. Furthermore, P300 latency was significantly longer in patients, and patients had significantly lower P300 amplitudes in frontal and central locations. In addition, P300 latency was found to be significantly correlated with bothersomeness during the ERP test, whereas P300 amplitude showed no such tendency.
Our study supports the notion that RLS patients have an underlying cognitive dysfunction. Significant correlations found between P300 latency and bothersomeness, a lack of sleepiness during the ERP test, and increased beta activity in resting state EEGs suggest that a combination of inattention and cortical dysfunction underlie cognitive dysfunction in RLS.
有报道称，不安腿综合征（RLS）患者可能存在认知缺陷。作者在白天进行脑电图和 ERP 分析，以确定未经药物治疗的 RLS 患者认知功能障碍与电生理的关系。
本研究纳入了 17 名未经药物治疗的 RLS 患者（53.7±9.6 岁）和 13 名年龄匹配的健康对照者。在清醒-休息状态和视觉Oddball 任务期间记录 EEG。使用国际 RLS 严重程度量表（International RLS Severity Scale）评估 RLS 严重程度。在 ERP 后立即测定斯坦福嗜睡量表（Stanford sleepiness scale，SSS）和困扰视觉模拟量表（bothersomeness visual analog scale，VAS）评分。比较患者和对照组的 EEG 功率谱和 P300 振幅和潜伏期。将临床变量与 P300 结果进行相关性分析。
清醒-休息 EEG 显示，RLS 患者额-中央区域的β活动明显高于对照组。两组 SSS 评分无差异。但 RLS 患者的困扰 VAS 评分明显高于对照组。此外，患者的 P300 潜伏期明显延长，额、中央部位的 P300 振幅明显降低。此外，P300 潜伏期与 ERP 测试期间的困扰程度显著相关，而 P300 振幅则无此趋势。
本研究支持 RLS 患者存在潜在认知功能障碍的观点。在 ERP 测试中，P300 潜伏期与困扰程度显著相关，且测试期间无嗜睡感，静息状态 EEG 中β活动增加，这表明注意力不集中和皮质功能障碍共同导致 RLS 的认知功能障碍。
