目的 探讨脑电图(electroencephalographic，EEG)对乙型脑炎的临床诊断价值。方法 收集62例确诊为乙型脑炎患者的EEG、CT和MRI检查结果，分别于入院后1个月、3个月进行随访，分析EEG特征及其与影像学、预后的关系。结果 62例EEG检查异常率为100%，发现2种类型的异常表现:弥散持续性δ波、棘波或尖波的癫样波。EEG与MRI、CT异常检出率比较，差异均有统计学意义(χ²=5.37，P=0.02;χ²=23.15，P<0.01)。62例中8例死于乙型脑炎急性期，10例失访。EEG异常类型与预后无相关性(P=0.75)。结论 乙型脑炎EEG与预后没有关联性，但作为一种辅助检查，在乙型脑炎的早期发现和提供诊断依据等方面有着重要的作用。

Objective To analyze the relationship of electroencephalographic (EEG) in Japanese encephalitis (JE) with CT, MRI and prognosis and to explore the clinical value of EEG in diagnosing JE. Methods Sixty two patients with JE were examined by EEG, CT and MRI. Follow-up examination was undertaken at 1 and 3 months after hospitalization. Results The abnormal incidence of EEG in 62 JE patients was 100% and higher than that of MRI (χ²=5.37,P=0.02) and CT (χ²=23.15,P<0.01). Two patterns of EEG were noted which included diffuse continuous delta and epileptiform discharges of spikes or sharp waves. Eight patients died in the acute stage and 10 patients were lost from follow-up. At 3 months, 21 patients had complete, 15 partial and 8 poor recovery. The EEG pattern did not correlate with the outcome (P=0.75). Conclusions In JE, EEG shows diffuse continuous delta and epileptiform discharges of spikes or sharp waves occasionally. Although there is no correlation of EEG pattern with the outcome of JE, the abnormal incidence of EEG is high and EEG can be used as reference for early diagnosis in JE disease.