Departments of Neurology, National Institute of Mental Health and Neurosciences, Hosur Road, Bangalore, Karnataka, India.
Seizure. 2024 Aug;120:157-164. doi: 10.1016/j.seizure.2024.07.004. Epub 2024 Jul 3.
The analysis of EEG demands expertise and keen observation to distinguish epileptiform discharges from benign epileptiform variants (BEVs), a frequent source of erroneous interpretation. The prevalence of BEVs varies based on geographical, racial, and ethnic characteristics. However, most data on BEVs originates from Western populations, and additional studies on different cohorts would enrich the existing literature.
We reviewed EEGs from our institutional database to study the prevalence of benign epileptiform variants and analyzed their frequency, topography, and other characteristics. Additionally, we investigated the co-existence of epileptiform discharges with BEVs.
We identified 296 patients with BEVs after reviewing 3000 EEGs (9.9%). The most common BEV was small sharp spikes (SSS), observed in 114 patients (3.8%). Wicket waves, 6 Hz spike and slow wave, 14 and 6 Hz positive bursts, and Rhythmic Temporal Theta of Drowsiness (RTTD) were identified in 67 (2.2%), 40 (1.3%), 39 (1.3%), and 35 (1.16%) patients, respectively and one patient with Subclinical Rhythmic EEG Discharges in Adults (SREDA). Additionally, we observed the co-existence of epileptiform discharges with BEVs, most commonly with SSS (27.8%).
The present study is a large study with 3000 EEGs to describe the BEV characteristics. BEVs were seen in 9.9% of patients, BSSS being the most common. There were minor differences in frequency, gender or age distribution compared to existing literature. We demonstrated the co-existence of epileptiform discharges. Morphological characteristics remain the cornerstone in recognising BEVs. EEG readers need to be aware of features of BEVs to avoid wrongly interpretation.
分析脑电图需要专业知识和敏锐的观察力，以便将癫痫样放电与良性癫痫样变异（BEV）区分开来，而后者是导致错误解读的常见原因。BEV 的发生率因地理位置、种族和民族特征而异。然而，大多数关于 BEV 的数据都来自于西方人群，对不同队列进行进一步研究将丰富现有的文献。
我们回顾了我们机构数据库中的脑电图，以研究良性癫痫样变异的发生率，并分析了它们的频率、分布和其他特征。此外，我们还研究了癫痫样放电与 BEV 的共存情况。
在对 3000 份脑电图进行回顾后，我们共发现 296 例 BEV 患者（9.9%）。最常见的 BEV 是小尖波（SSS），见于 114 例患者（3.8%）。棘慢复合波、6Hz 棘慢波、14Hz 和 6Hz 正相波、困倦时节律性颞区 theta 波（RTTD）分别见于 67 例（2.2%）、40 例（1.3%）、39 例（1.3%）和 35 例（1.16%）患者，且 1 例患者存在亚临床节律性脑电图放电成人（SREDA）。此外，我们观察到癫痫样放电与 BEV 共存，最常见的是与 SSS 共存（27.8%）。
本研究是一项包含 3000 份脑电图的大型研究，用于描述 BEV 的特征。9.9%的患者存在 BEV，最常见的是 BSSS。与现有的文献相比，其在频率、性别或年龄分布方面存在一些差异。我们证明了癫痫样放电与 BEV 的共存。形态学特征仍然是识别 BEV 的基石。脑电图解读者需要了解 BEV 的特征，以避免错误解读。
