Abstract:

Objective  To investigate the clinical and EEG features of ischemic stroke patients with abnormal discharges.  Methods  Clinical data and 24-hour EEG monitoring of 162 ischemic stroke patients were analyzed retrospectively. One-year follow-up was carried out and post-ischemic epilepsy was diagnosed.  Results  Among 162 ischemic stroke patients, 24-hour EEG was abnormal in 87 cases (53.70%). According to the correspondence of site of infarcts and abnormal discharges, these 87 cases were classified into 2 groups: matched group (N = 24, 27.59%) and unmatched group (N = 63, 72.41%). There was no significant difference between 2 groups in terms of Oxfordshire Community Stroke Project (OCSP) and TOAST classification (P = 0.792, 0.111), while there was significant difference between 2 groups on the site of infarcts (P = 0.000). In matched group, the infarcts were mainly located in cortex (N = 23, 95.83%). However, in unmatched group, the infarcts were mainly located in cortex and basal ganglia (N = 27, 42.86%), or in basal ganglia only (N = 24, 38.10%). In matched group, 24-hour EEG showed slowing of background activities, and sharp waves and sharp and slow wave complex which were corresponding to the infarct sites. The abnormal discharges could only be recorded around the infarct unilaterally. In unmatched group, the epileptiform discharges were recorded in both contralateral and ipsilateral ischemic hemispheres, usually with widespread slow waves and asymmetric background. The infarcts were limited, but abnormal discharges were widespread. For example, the infarct was located in deep brain, while scalp abnormal discharges were recorded. Although there was no significant difference in terms of epilepsy incidence between 2 groups (P = 0.908), the types of epilepsy were statistically different between 2 groups (P = 0.000). In matched group, the main type was partial seizure. But in unmatched group, the main types of epilepsy were secondary generalized seizure and generalized seizure.  Conclusions  Infract site has an influence on the abnormal EEG pattern, and the unmatched location of ischemic region and abnormal EEG may be indicative for the seizure type of post-ischemic epilepsy.

Key words: Brain ischemia, Epilepsy, Electroencephalography

摘要：

目的 探讨缺血性卒中后异常脑电发放的临床及脑电图特征。方法 回顾分析162 例缺血性卒中患者临床和24 h 动态脑电图特征。结果 162 例缺血性卒中患者中87 例（53.70%）24 h 动态脑电图异常，其中24 例（27.59%）梗死灶部位与脑电图异常放电部位相一致（一致组）、63 例（72.41%）不一致（不一致组）。两组患者缺血性卒中临床分型［英国牛津郡社区脑卒中项目（OCSP）分型］和病因分型（TOAST 分型）差异均无统计学意义（P = 0.792，0.111），梗死灶部位差异有统计学意义（P = 0.000）。一致组患者24 h 动态脑电图可见背景节律慢化，以及尖波和尖-慢复合波，且与梗死灶部位相一致；不一致组患者各导联背景节律均发生变化，梗死灶位于单侧大脑半球者可见对侧大脑半球异常放电，梗死灶范围局限但脑电图可见异常放电范围广泛，梗死灶仅位于皮质下脑深部结构但可于头皮电极记录到异常放电。两组患者癫痫发生率差异无统计学意义（P = 0.908），而癫痫发作类型差异有统计学意义（P = 0.000）。结论 梗死灶部位影响异常脑电活动的发放和扩布，其与记录到异常放电的导联部位不一致对缺血性卒中后癫痫发作类型和预后有提示作用。

关键词: 脑缺血, 癫痫, 脑电描记术