Event-related potential biomarkers in temporal lobe epilepsy: N170, vertex positive potential, late positive potential, and P3 signatures of depression comorbidity.

Abstract

Objective: This study aimed to identify which components of the event-related potentials N170, vertex positive potential, late positive potential, and P3 were most significantly associated with depression in temporal lobe epilepsy.

Methods: Patients with temporal lobe epilepsy were divided into two groups based on the presence or absence of comorbid depression as diagnosed by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition: those with depression (epilepsy patients with depression group) and those without depression (epilepsy patients without depression group). Both groups were matched for age, education, and seizure-related parameters. A control group of volunteers without epilepsy and depression was also included. Participants underwent electroencephalographic recordings while performing the Oddball task, and the emotional conflict Stroop face-word task. The electroencephalographic data were analyzed using the EEGLAB software.

Results: The study included 20 patients in the epilepsy patients with depression group and 16 in the epilepsy without depression group, matched for age, gender, and seizure-related parameters. In the epilepsy patients with depression group, the N170 peak amplitude and latency, the vertex positive potential peak latency, and the area under the late positive potential waveform were significantly greater, while the P3 peak latency was shorter compared to the epilepsy without depression group. The areas under the curve for N170, vertex positive potential, late positive potential, and P3 were 0.755, 0.692, 0.645, and 0.731, respectively. Notably, when these four event-related potential components were combined, the areas under the curve increased to 0.922, with a sensitivity of 0.950 and specificity of 0.812 for assessing depression based on the 17-item Hamilton Depression Rating Scale score.

Conclusion: Specific features of N170, vertex positive potential, late positive potential, and P3 components were significantly associated with depression in patients with temporal lobe epilepsy. These findings suggest that event-related potential components may provide an objective and quantitative approach to enhance the assessment and treatment of depression in epilepsy.