Emmady Prabhu D., Asuncion Ria Monica D., Anilkumar Arayamparambil C.
UNC school of Medicine, Atrium Health
University of Santo Tomas, Medicine and Surgery
The electroencephalogram (EEG) is a noninvasive technique for measuring neurophysiological activity. This evaluation modality serves as a valuable tool for analyzing the brain's complex functions by detecting electrical activity. EEG signals reflect the brain’s electrical function and are recorded by placing electrodes on the scalp to measure cortical neuron activity. Hans Berger first used EEG in humans in 1924, publishing his findings in 1929. EEG records voltage fluctuations over time from multiple scalp electrodes arranged in a specific pattern to sample different cortical regions. These signals represent fluctuating dendritic potentials from superficial cortical layers, requiring voltage amplification for proper recording. However, extracranial electrodes do not effectively capture deep brain activity. EEG waveforms result from the summation of excitatory (EPSPs) and inhibitory postsynaptic potentials (IPSPs) in cortical neurons. Some benign EEG variants appear normal but may be mistaken for epileptiform activity. Abnormal EEG waveforms include both epileptiform and nonepileptiform abnormalities. Recognizing the differences requires understanding normal EEG patterns across different physiological states in children and adults. Electroencephalographers must also distinguish artifacts from true abnormalities and identify benign variants. This article reviews abnormal EEG waveforms and their clinical significance.
脑电图（EEG）是一种用于测量神经生理活动的非侵入性技术。这种评估方式通过检测电活动，成为分析大脑复杂功能的宝贵工具。EEG信号反映大脑的电功能，通过将电极放置在头皮上以测量皮质神经元活动来进行记录。汉斯·伯格于1924年首次在人类身上使用EEG，并于1929年发表了他的研究结果。EEG记录按照特定模式排列的多个头皮电极随时间的电压波动，以对不同的皮质区域进行采样。这些信号代表来自皮质浅层波动的树突电位，需要进行电压放大才能进行适当记录。然而，颅外电极无法有效捕捉深部脑活动。EEG波形是由皮质神经元中兴奋性（兴奋性突触后电位）和抑制性突触后电位的总和产生的。一些良性EEG变异看似正常，但可能被误认为癫痫样活动。异常EEG波形包括癫痫样和非癫痫样异常。要识别这些差异，需要了解儿童和成人在不同生理状态下的正常EEG模式。脑电图检查人员还必须区分伪迹与真正的异常，并识别良性变异。本文综述了异常EEG波形及其临床意义。
