PURPOSE When performed correctly, hyperventilation (HV) for three minutes provokes absence seizures in virtually all children, a finding suggestive of a diagnosis of childhood absence epilepsy (CAE). Interestingly, some children experience absence seizures while performing HV in the office yet do not experience absences during HV on subsequent routine EEG. In most instances, HV during routine EEG is performed in the supine position, while in the office HV is done with the child sitting-up. Therefore, we hypothesized that the position in which HV is performed may influence its yield in provoking absence seizures. METHODS We conducted a randomized multi-center controlled trial among children (4-10 years old) with suspected CAE. During a routine EEG, children were asked to perform HV twice, in the supine and sitting positions. RESULTS Twenty children (four males) diagnosed with CAE were included in the analysis. Seventeen of the 20 patients experienced absence seizures while sitting and 13 experienced seizures during supine HV (p = 0.031). All patients that had absence seizures during supine HV also had seizures during sitting HV. Among patients with absences in both positions, seizure duration was significantly shorter during sitting HV (mean 8.69 seconds) than during supine HV (mean 12 seconds) (p = 0.042). An opposite tendency was seen in the younger age group (4-7 years), with shorter seizures in the supine HV group (5.6 seconds supine, 7.57 seconds sitting, p = 0.019). CONCLUSIONS HV in the sitting position may increase the yield of provoking absence seizures during routine EEGs, thereby improving its sensitivity in the diagnosis of CAE.

中文翻译：

---

常规脑电图检查中无癫痫发作：过度换气期间孩子的位置会影响诊断率吗？

目的正确执行三分钟的换气过度（HV）会引起几乎所有儿童的癫痫发作，这一发现暗示了对儿童癫痫发作（CAE）的诊断。有趣的是，一些孩子在办公室进行HV时会出现神志不清的癫痫发作，而在随后的常规脑电图上进行HV时不会失神。在大多数情况下，常规EEG期间的HV是仰卧姿势进行的，而在办公室，HV是在儿童仰卧起坐的情况下进行的。因此，我们假设执行HV的位置可能会在引起失神发作时影响其产量。方法我们对疑似CAE的儿童（4-10岁）进行了一项多中心随机对照试验。在例行脑电图检查中，要求儿童在仰卧位和坐位进行两次HV。结果分析包括20名被诊断为CAE的儿童（4名男性）。20例患者中有17例在坐时出现癫痫发作，而13例在仰卧HV期间癫痫发作（p = 0.031）。所有在仰卧HV期间无癫痫发作的患者在坐HV期间也有癫痫发作。在两个位置均不存在的患者中，坐位HV（平均8.69秒）的发作时间明显比仰卧HV（平均12秒）的发作时间短（p = 0.042）。在较年轻的年龄组（4-7岁）中观察到相反的趋势，仰卧HV组的癫痫发作时间较短（仰卧5.6秒，坐姿7.57秒，p = 0.019）。结论坐位的HV可能会增加常规EEG发作性癫痫发作的发生率，从而提高其在CAE诊断中的敏感性。