Spatio-Temporal Responses of Emotional Conflict and Psychiatric Correlation in Adolescent Epilepsy Patients

Research Background

Epilepsy patients often experience comorbid mental disorders such as depression and anxiety, which negatively impact their quality of life. Emotional regulation is a critical cognitive process that is frequently impaired in patients with mental disorders, such as those with depression. Adults with epilepsy also face difficulties with emotion regulation, especially in higher-order cognitive processing stages. However, the spatio-temporal frequency associations of these functional brain deficits in epilepsy patients, especially in adolescents, have not been fully explored. Therefore, this study aims to use magnetoencephalography (MEG) to analyze the spatio-temporal characteristics of emotional conflict processing in adolescent epilepsy patients and associate these findings with the severity of anxiety and depression symptoms evaluated through self-report scales.

Research Source

The main authors of this study are F. Kathryn King, M. Scott Perry, Christos Papadelis, and Crystal M. Cooper, hailing from Cook Children’s Health Care System, University of Texas at Arlington, Texas Christian University School of Medicine, and UT Southwestern Medical Center. The paper was published on June 7, 2024, in the journal Epilepsy & Behavior.

Research Process

Participants

This study included 53 adolescent participants, consisting of 28 epilepsy patients (14 with focal epilepsy and 14 with generalized epilepsy) and 25 healthy controls. The age range of participants was 10 to 20 years, with an average age of 14.62 (±2.63) years. The diagnosis of epilepsy was based on clinical symptoms and video/EEG monitoring, with exclusion criteria including severe neurological or developmental disorders.

Psychiatric Symptom Assessment

The 7-item Generalized Anxiety Disorder Questionnaire (GAD-7) and the 9-item Patient Health Questionnaire (PHQ-9) were used to assess the severity of anxiety and depression symptoms among participants. The results showed no significant differences between epilepsy patients and healthy controls in the severity of anxiety and depression symptoms. However, patients with focal epilepsy tended to have higher depression symptom severity, though these differences were not statistically significant.

Emotional Conflict Task

An emotional face-word Stroop task was used to test emotional conflict responses, where participants had to respond to the expressed emotion of displayed faces while ignoring the emotional words overlaid on the faces. The task included 74 black-and-white face images presented for 1000 ms each, with an inter-trial interval of 3-5 seconds, totaling 444 trials.

MEG Data Collection and Processing

MEG data were recorded using a whole-head Neuromag® Triux 306 sensor system, with a sampling rate of 1 kHz. High spatial and temporal resolution head models were computed using the Boundary Element Method (BEM) head model, and source localization was estimated using Dynamic Statistical Parametric Mapping (DSPM).

Data Analysis

Cluster-Based Permutation Tests were used to detect differences in brain activity during the emotional conflict task between adolescent epilepsy patients and controls. The results indicated that epilepsy patients exhibited delayed brain responses during emotional conflict processing, particularly in the 500 ms to 1000 ms time window.

Main Results

Behavioral Performance

Behaviorally, controls exhibited slower reaction times and lower accuracy during emotional conflict, while epilepsy patients did not show this typical behavioral interference effect. There were behavioral pattern differences between epilepsy subgroups, with focal epilepsy patients showing interference in reaction time, while generalized epilepsy patients did not demonstrate significant behavioral differences.

Brain Response Differences

MEG data analysis revealed that epilepsy patients had reduced brain activity within specific spatio-temporal windows (500-1000 ms), primarily located in the left post-central gyrus, middle cingulate gyrus, left precuneus, hippocampus, fusiform gyrus, and right middle cingulate gyrus, orbitofrontal cortex, and anterior cingulate cortex (ACC).

Time-Frequency Analysis

Time-frequency analysis disclosed event-related desynchronization (ERD) in the beta band within the left pre-subgenual cingulate cortex during the 600-1000 ms period, associated with the inhibition responses to emotional conflict.

Psychiatric Symptom Correlation

There was a significant correlation between neural activity and the severity of psychiatric symptoms among epilepsy subgroups. In focal epilepsy patients, brain activity in the 500-600 ms time window was related to anxiety and depression symptoms, while in generalized epilepsy patients, brain activity in the 600-700 ms window was associated with anxiety symptoms.

Conclusion and Significance

This study revealed for the first time the spatio-temporal characteristics and neural correlations of emotional conflict processing in adolescent epilepsy patients and found differential associations between brain responses and psychiatric symptoms among epilepsy subgroups. These findings provide potential research and therapeutic targets to further understand and treat emotional regulation deficits in epilepsy patients. Future research should consider epilepsy types, foci, age, and comorbid psychiatric symptoms to provide personalized treatments for epilepsy patients.

Research Highlights

• This study is the first to use MEG to explore the spatio-temporal characteristics of emotional conflict processing in adolescent epilepsy patients.
• Differences in behavioral and brain responses during the emotional conflict task were found among epilepsy subgroups.
• The study confirmed the association between brain activity and the severity of psychiatric symptoms, providing potential therapeutic targets.

This research has made significant progress in revealing the emotional conflict processing and neural mechanisms of adolescent epilepsy patients, offering new directions and insights for future research and treatment.