Lum Leanna M, Connolly Mary B, Farrell Kevin, Wong Peter K H
Department of Diagnostic Neurophysiology, B.C. Children's Hospital, Vancouver, British Columbia, Canada.
Epilepsia. 2002 Nov;43(11):1372-8. doi: 10.1046/j.1528-1157.2002.35101.x.
Hyperventilation-induced high-amplitude rhythmic slowing (HIHARS) in children may be associated with clinical episodes of altered awareness. The presence of automatisms has been proposed as a distinguishing feature that helps to differentiate absence seizures from nonepileptic causes of decreased responsiveness. This retrospective, controlled, video-EEG study compared the clinical characteristics of episodes of HIHARS with loss of awareness with those of absence seizures.
The database of a tertiary Children's Hospital was searched for patients studied between April 1993 and April 1997 who had at least one episode of HIHARS with loss of awareness. The absence control group was obtained by selecting the next patient, after an HIHARS study subject, who met the following criteria: (a) had at least one absence seizure occurred during hyperventilation in the EEG recording, and (b) had a diagnosis of idiopathic generalized epilepsy. The video-EEG and medical histories of all patients were reviewed and summarized.
We reviewed video-EEG recordings of 77 episodes of HIHARS with loss of awareness from 22 children and 107 absence seizures during hyperventilation from 22 children. Eye opening and eyelid flutter were seen more frequently in absence seizures, whereas fidgeting, smiling, and yawning occurred more frequently during HIHARS episodes. Arrest of activity, staring, and oral and manual automatisms were observed in both groups.
Automatisms are common in both HIHARS and absence seizures. Yawning, smiling, and particularly fidgeting occur more commonly and eye opening and eyelid flutter less commonly in HIHARS. However, episodes of HIHARS with loss of awareness clinically mimic absence seizures, and these conditions can be distinguished reliably only by EEG.
儿童过度换气诱发的高幅节律性慢波（HIHARS）可能与意识改变的临床发作有关。有人提出自动症的存在是一个有助于区分失神发作与反应性降低的非癫痫性病因的显著特征。这项回顾性、对照、视频脑电图研究比较了伴有意识丧失的HIHARS发作与失神发作的临床特征。
检索一家三级儿童医院的数据库，查找1993年4月至1997年4月期间接受研究且至少有一次伴有意识丧失的HIHARS发作的患者。失神对照组是通过在一名HIHARS研究对象之后选择下一名符合以下标准的患者获得的：（a）脑电图记录中过度换气期间至少发生一次失神发作，（b）诊断为特发性全身性癫痫。对所有患者的视频脑电图和病史进行了回顾和总结。
我们回顾了22名儿童的77次伴有意识丧失的HIHARS发作的视频脑电图记录以及22名儿童在过度换气期间的107次失神发作。睁眼和眼睑颤动在失神发作中更常见，而坐立不安、微笑和打哈欠在HIHARS发作期间更频繁出现。两组均观察到活动停止、凝视以及口部和手部自动症。
自动症在HIHARS和失神发作中都很常见。打哈欠、微笑，尤其是坐立不安在HIHARS中更常见，而睁眼和眼睑颤动在HIHARS中较少见。然而，伴有意识丧失的HIHARS发作在临床上模仿失神发作，并且这些情况只能通过脑电图可靠地区分。
