Objective

Cognitive impairment in temporal lobe epilepsy is widely acknowledged as one of the most well-known comorbidities. This study aimed to explore cognitive impairment and to determine the potential clinical, radiological, and quantitative electroencephalography markers for cognitive impairment in temporal lobe epilepsy patients versus extra-temporal lobe epilepsy.

Methods

Forty-five patients with temporal lobe epilepsy and forty-five patients with extra-temporal lobe epilepsy were recruited for an administered digit span test, verbal fluency test, mini-mental state examination, digital symbol test, and Montreal cognitive assessment. Also, they were subjected to magnetic resonance imaging assessment for hippocampal atrophy and a quantitative electroencephalography assessment for electroencephalography markers (median frequency, peak frequency, and the alpha-to-theta ratio).

Results

Patients with extra-temporal lobe epilepsy showed non-significant higher epilepsy durations and a higher frequency of seizures. Temporal lobe epilepsy patients showed a more statistically significant family history of epilepsy (37.7%), more history of febrile convulsions (13.3%), higher hippocampal atrophy (17.8%), and lower cognitive scales, especially mini-mental state examination and Montreal cognitive assessment; lower digital symbol test, verbal fluency test, and backward memory of digit span test. Also, temporal lobe epilepsy patients had a strong negative correlation with electroencephalography markers: median frequency, peak frequency, and the alpha-to-theta ratio (r = − 0.68, P < 0.005 and r = − 0.64, P < 0.005 and r = − 0.66, P < 0.005 respectively).

Conclusion

Cognitive impairment in patients with temporal lobe epilepsy was correlated with hippocampal atrophy and quantitative electroencephalography abnormalities, especially peak frequency, median frequency, and alpha-to-theta ratio that could be used alone for the identification of early cognitive impairment.

Trial registration

Clinicaltrials.gov: NCT04376671.

中文翻译：

---

颞叶癫痫与颞叶外癫痫轻度认知障碍的海马萎缩和定量脑电图标志物

目标

颞叶癫痫的认知障碍被广泛认为是最知名的合并症之一。本研究旨在探索认知障碍，并确定颞叶癫痫患者与颞叶外癫痫患者认知障碍的潜在临床、放射学和定量脑电图标志物。

方法

招募了 45 名颞叶癫痫患者和 45 名颞叶外癫痫患者进行数字跨度测试、语言流畅性测试、小型精神状态检查、数字符号测试和蒙特利尔认知评估。此外，他们还接受了海马萎缩的磁共振成像评估和脑电图标志物的定量脑电图评估（中频、峰值频率和 α 与 θ 之比）。

结果

颞叶外癫痫患者的癫痫持续时间较长，癫痫发作频率较高，但并不显着。颞叶癫痫患者的癫痫家族史（37.7%）、热性惊厥史（13.3%）、海马萎缩程度更高（17.8%）、认知量表较低，尤其是小型精神状态检查和蒙特利尔认知量表评估；下位数字符号测试、语言流畅度测试、数字跨度后向记忆测试。此外，颞叶癫痫患者与脑电图标志物呈强烈负相关：中位频率、峰值频率和 α-θ 比（r  = − 0.68，P  < 0.005 和r  = − 0.64，P  < 0.005 和r  = − 0.66， 分别为P < 0.005）。

结论

颞叶癫痫患者的认知障碍与海马萎缩和定量脑电图异常相关，尤其是峰值频率、中位频率和 α-θ 比值可单独用于识别早期认知障碍。

试用注册

Clinicaltrials.gov：NCT04376671。