Characterizing Prevalence of Psychiatric Conditions and the Fear-Potentiated Startle Response in Trauma-Exposed People with Epilepsy Restricted; Files Only

Zeleke, Helena (Spring 2023)

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Epilepsy is a neurological condition characterized by recurrent, uncontrolled neuronal activity and affects ~50 million people globally. Prior literature suggests that depression, PTSD, and suicidality are more prevalent among people with epilepsy than in people without epilepsy; however, most prior studies are limited in their generalizability as their sampling excludes racially marginalized and highly trauma-exposed individuals and/or fails to include seizure-free comparison groups. Existing knowledge of the overlapping neurocircuitry between certain types of epilepsy (e.g., medial temporal lobe epilepsy) and PTSD also suggests that people with epilepsy may exhibit PTSD-like alterations in their psychophysiological responses, namely altered fear-potentiated startle response (FPS). However, this hypothesis has yet to be systematically tested. This study examined prevalence of PTSD symptoms, depression symptoms, suicidality, and history of suicide attempt among 3,012 racially marginalized and low resourced civilians. Additionally, we measured and compared FPS in 8 people with epilepsy to the FPS of 8 rigorously matched seizure-free controls. The modified PTSD symptom (mPSS) scale was used to measure PTSD symptoms and Beck’s Depression Inventory was used to measure depression and suicidality symptoms. Self-report survey questions were used to assess past suicide attempt and seizures/epilepsy status. FPS was measured using EMG data collected during a fear conditioning acoustic startle task. Participants with seizures/epilepsy showed significantly higher prevalence of depression symptoms, suicidality, history of suicide attempt, PTSD symptoms, and probable PTSD diagnosis than participants without seizures/epilepsy, even after controlling for trauma load. FPS did not differ significantly between the epilepsy and no epilepsy groups; however, a near-significant interaction between task phase and epilepsy status was detected. Our study shows that, within a majority racially-marginalized sample with high levels of trauma exposure, people with epilepsy are still more likely to have a variety of psychiatric comorbidities than people without epilepsy. This finding underscores the vulnerability of individuals with a history of seizures/epilepsy as well as the importance of accessible psychotherapy for this at-risk group. Furthermore, our FPS data serves as a first step in characterizing the fear response of people with epilepsy, our understanding of which can be bolstered with future studies using larger sample sizes. 

Table of Contents

Introduction 2

Characteristics and Prevalence of Epilepsy 2

Epilepsy, Trauma, and Post-traumatic Stress Disorder 2

Other Psychiatric Comorbidities in Epilepsy 4

Epilepsy and Depression 4

Epilepsy and Suicidality 4

Startle Response and Fear Neurocircuitry in Epilepsy 5

Study Aims 7

Methods 8

Demographic and Clinical Variables 8

Statistical analyses 10

Fear-Potentiated Startle Response Data Collection and Analysis 10

Participants 10

Startle procedure 11

Startle data processing 12

Statistical analyses 12

Results 13

Participant Demographics 13

Psychological Symptoms in People with and without Seizures/Epilepsy 13

Relationship Between Trauma Exposure, Seizure/Epilepsy Status, and Psychological Symptoms 13

Relationship Between Fear-Potentiated Startle Response and Epilepsy 14

Discussion 15

Limitations and Future Directions 18

Conclusion 18

References 19

Figures and Tables 26

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