Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark, Department of Clinical Medicine, Aarhus University, Denmark.
Department of Clinical Neurophysiology, Danish Epilepsy Centre, Dianalund, Denmark.
Epileptic Disord. 2022 Apr 1;24(2):315-322. doi: 10.1684/epd.2021.1392.
To characterize in detail the electroclinical features of typical absence seizures and elucidate whether EEG or semiology features, alone or in combination, can predict long-term therapeutic outcome.
We analysed video-EEG recordings from 213 typical absence seizures from 61 patients with idiopathic generalized epilepsy. We extracted semiological features, in addition to hallmark manifestations (motor/behavioural arrest, non-responsiveness), their location, timing and frequency. We evaluated the duration and frequency of generalized spike-wave discharges and the presence of polyspikes. We used a supervised machine-learning approach (random forest) to search for classifier features for long-term therapeutic outcome (>one year).
Besides the hallmark manifestations, additional semiological features were identified in 87% of patients (75% of seizures). The most common additional semiological features were automatisms and eye blinking (observed in 45% and 41.5% of seizures, respectively). Automatisms were associated with longer seizure duration, and oral automatisms occurred earlier compared to limb automatisms (4.03 vs. 6.19 seconds; p=0.005). The mean duration of the ictal spike-wave discharges was nine seconds, and the median frequency was 3 Hz. Polyspikes occurred in 46 seizures (21.6%), in 19 patients (31%). Median follow-up was five years, and 73% of the patients were seizure-free at the end of the follow-up. None of the semiological features, alone or in combination, were predictors of therapeutic outcome. The only significant classifier was the presence of polyspikes, predicting a non-seizure-free outcome with an accuracy of 73% (95% CI: 70-77%), positive predictive value of 92% (95% CI: 84-98%) and negative predictive value of 60% (95% CI: 39-81%).
Semiological features, in addition to behavioural arrest and non-responsiveness, are common in typical absence seizures, but they do not predict long-term therapeutic outcome. The presence of polyspikes has a high positive predictive value for unfavourable therapeutic outcome, and their presence should therefore be included when reporting EEGs in patients with typical absence seizures.
详细描述典型失神发作的临床电特征，并阐明脑电图或症状学特征，单独或联合使用，是否可以预测长期治疗效果。
我们分析了 61 例特发性全面性癫痫患者 213 例典型失神发作的视频脑电图记录。除了标志性表现（运动/行为中止、无反应）外，我们还提取了症状学特征，包括其位置、时间和频率。我们评估了全面性棘慢波放电的持续时间和频率以及多棘波的存在。我们使用监督机器学习方法（随机森林）来寻找长期治疗效果（>1 年）的分类器特征。
除标志性表现外，87%的患者（75%的发作）还存在其他症状学特征。最常见的附加症状学特征是自动症和眨眼（分别观察到 45%和 41.5%的发作）。自动症与发作持续时间较长有关，口腔自动症比肢体自动症出现得更早（4.03 秒对 6.19 秒；p=0.005）。发作期棘慢波放电的平均持续时间为 9 秒，中位数频率为 3Hz。46 次发作（21.6%）、19 名患者（31%）出现多棘波。中位随访时间为 5 年，随访结束时 73%的患者无发作。单独或联合使用的症状学特征均不能预测治疗效果。唯一有意义的分类器是多棘波的存在，其准确性为 73%（95%CI：70-77%），阳性预测值为 92%（95%CI：84-98%），阴性预测值为 60%（95%CI：39-81%），可预测非无发作的治疗结局。
除行为中止和无反应外，典型失神发作中常见症状学特征，但不能预测长期治疗效果。多棘波的存在对治疗效果不佳有较高的阳性预测值，因此在报告典型失神发作患者的脑电图时应包括多棘波的存在。
