An interventional study of Electrical Stimulation in Refractory Epilepsy, sponsored by Dartmouth-Hitchcock Medical Center. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-22.
Sponsored by Dartmouth-Hitchcock Medical Center · Not applicable, Interventional, and Basic science
This study will enroll patients with epilepsy who are being evaluated for epilepsy surgery and have intracranial EEG electrodes. In this study, the aim is to record brain signals from areas important in social and emotional processing and to understand how electrical brain stimulation - called neuromodulation - affects such processing. Patients enrolled in this study will be asked to view images depicting a variety of emotionally positive, negative, or neutral themes. As the patient views these images, a small amount of imperceptible and painless electric current will be used to map function of certain parts of a human brain. The overarching goal of the study is to determine if neuromodulation can be used in certain areas of the brain to treat cognitive disorders such as memory loss and post-traumatic stress disorder.
One to two study tasks will be performed by each participant to help us understand how the brain processes emotion and how stimulation effects emotional processing.
These study tasks will last up to several minutes each, and generally require participants to view pictures while EEG recordings are made from the electrodes placed in specific areas of the brain. The routine video/EEG monitoring and brain function testing should not be disrupted or prolonged by the study testing, and if a participant has a seizure during the testing, it will be recorded as usual for review by participant's providers.
The following study procedures will likely be carried out in each individual case:
Recording from areas important in social and emotional processing.
A computer monitor will be used to present pictures of people engaged in social interaction. Additionally, the researchers will present individual participants with well standardized tasks designed to understand the nature of emotions. Some of these images may be emotionally disturbing. Should participants become uncomfortable with viewing such images, participants would be provided with a choice to not participate in this study.
Using brain stimulation to map function of certain parts of your brain.
A brain stimulator will be used -normally used to map where important brain regions are located-to understand new functions of the brain. Each participant will be presented with pictures on a computer screen. As participant(s) views these pictures, the brain stimulator may be activated (this is not something that is felt by a person) and an electrical stimulation through the implanted electrodes will be delivered to specific regions of the brain. Research team will be measuring how brain stimulation may affect each individual's emotional response to a specific stimulus.
This questionnaire will be given to ensure the stimulation doesn't increase any unpleasant emotional experience for participants. This will take place before and during the stimulation of a specific part of the brain.
261 studies on the registry are indexed under Drug Resistant Epilepsy; 99 are open to participants now.
This study's enrollment of 16 is below the median of 30 across 208 interventional studies indexed under Drug Resistant Epilepsy.
Browse Drug Resistant Epilepsy studies →Dartmouth-Hitchcock Medical Center is the lead sponsor of 472 studies on the registry; 68 are open to participants now.
Of its 30 completed or terminated interventional studies of FDA-regulated products, 20 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
This part will include 24 randomly chosen images from each of four categories (total of 96 images varying in valence and arousal) and will be presented block-randomized amygdala stimulation.
Other: Electrical Stimulation
This part will include 24 randomly chosen images from each of four categories (total of 96 images varying in valence and arousal) and will be presented without amygdala stimulation.
We will use a computer randomized stimulation of specific areas in the amygdala while showing a computer randomized set of pictures.
Z-score Gamma Power in Amygdala Per Valence Category
Valence of each image is assessed by each subject using a Likert-type rating scale with a range of 1 to 7, where 1 represents most negative valence, 4 as neutral, and 7 as most positive. Valence categories are defined in the following manner: negative = 1.0 to 3.0, neutral = 3.1 to 5.0, negative = 5.1 to 7.0. Activation is measured by gamma frequency power (mµV²/30-100 Hz) at 0-1000 msec following image presentation in the basolateral amygdala electrode contact and compared to baseline defined as -500 msec to 0 of image presentation. Gamma power is transformed to z-score (baseline to following image presentation) for individual observations. Z-score of 0 indicates no change from baseline. Positive z-score indicates activation of the basolateral amygdala compared to baseline. Gamma frequency range is defined as 30-100 Hz in intracranial EEG. Power was estimated via a multitaper time-frequency transformation approach. Statistics was done using linear-mixed effects models (LMEs).
Time frame: 0 to 1000 MS following image presentation
Effect of Amygdala Stimulation on Perception of Valence
Here we assess the effect of basolateral amygdala stimulation on valence ratings. Participants rate the emotional valence of each image in a Likert scale range of 1-7 (1= maximum negative valence, 4=maximum neutral valence, and 7 maximum positive valence) for each of the 96 images. We randomly apply electrical stimulation during perception and of 50% of the images presented. We analyze the effect of stimulation on image rating in the following manner: we grouped the images into three categories, negative (1 to 3), neutral (3.1 to 5), and positive (5.1 to 7) based on subject specific ratings. 2. We then used a multivariate model to assess the effect of stimulation on perception of neutral, negative, and positive categories across 9 patients.
Time frame: Valence ratings were assessed immediately following the viewing of each image during performance of the task.
| Milestone | Entire Study Population |
|---|---|
| Started | 16 |
| Completed | 15 |
| Not completed | 1 |
| Withdrew: Adverse event | 1 |
Valence of each image is assessed by each subject using a Likert-type rating scale with a range of 1 to 7, where 1 represents most negative valence, 4 as neutral, and 7 as most positive. Valence categories are defined in the following manner: negative = 1.0 to 3.0, neutral = 3.1 to 5.0, negative = 5.1 to 7.0. Activation is measured by gamma frequency power (mµV²/30-100 Hz) at 0-1000 msec following image presentation in the basolateral amygdala electrode contact and compared to baseline defined as -500 msec to 0 of image presentation. Gamma power is transformed to z-score (baseline to following image presentation) for individual observations. Z-score of 0 indicates no change from baseline. Positive z-score indicates activation of the basolateral amygdala compared to baseline. Gamma frequency range is defined as 30-100 Hz in intracranial EEG. Power was estimated via a multitaper time-frequency transformation approach. Statistics was done using linear-mixed effects models (LMEs).
| z-score | Gamma Power in the Amygdala According to Valence Category |
|---|---|
| Gamma power positive images | 1.21 ± 0.23 |
| Gamma power, negative valence images | 1.88 ± 0.78 |
| Gamma power, neutral images | 1.24 ± 0.24 |
Here we assess the effect of basolateral amygdala stimulation on valence ratings. Participants rate the emotional valence of each image in a Likert scale range of 1-7 (1= maximum negative valence, 4=maximum neutral valence, and 7 maximum positive valence) for each of the 96 images. We randomly apply electrical stimulation during perception and of 50% of the images presented. We analyze the effect of stimulation on image rating in the following manner: we grouped the images into three categories, negative (1 to 3), neutral (3.1 to 5), and positive (5.1 to 7) based on subject specific ratings. 2. We then used a multivariate model to assess the effect of stimulation on perception of neutral, negative, and positive categories across 9 patients.
| units on a scale | Entire Study Population |
|---|---|
| Neutral no stimulation | 3.27 ± 0.78 |
| Neutral stimulation | 3.64 ± 0.48 |
| Positive valence; no stimulation | 5.26 ± 0.67 |
| Positive valence; stimulation | 5.08 ± 0.94 |
| Negative valence, no stimulation | 2.02 ± 0.66 |
| Negative valence, stimulation | 2.08 ± 0.59 |
Collected over during testing sessions for this study or 1 day. Non-serious events are listed at a 1% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Stimulation | 0/15 (0%) | 0/15 (0%) | 1/15 (6.7%) |
| No Stimulation | 0/15 (0%) | 0/15 (0%) | 1/15 (6.7%) |
| Event | Stimulation | No Stimulation |
|---|---|---|
| Covid-19 InfectionRespiratory, thoracic and mediastinal disorders | 1/15 | 1/15 |
| SeizureNervous system disorders | 1/15 | 1/15 |
This population is the same as the recruited patients in participant flow
| Age, Categorical(Participants) | The Entire Study Population |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 15 |
| >=65 years | 0 |
| Sex: Female, Male(Participants) | The Entire Study Population |
|---|---|
| Female | 6 |
| Male | 9 |
| Ethnicity (NIH/OMB)(Participants) | The Entire Study Population |
|---|---|
| Hispanic or Latino | 1 |
| Not Hispanic or Latino | 14 |
| Unknown or Not Reported | 0 |
| Race (NIH/OMB)(Participants) | The Entire Study Population |
|---|---|
| American Indian or Alaska Native | 0 |
| Asian | 0 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 0 |
| White | 14 |
| More than one race | 0 |
| Unknown or Not Reported | 1 |
Documents are hosted by the registry — open the source record to download them.
Plan to share: No — The study results will be available on ClinicalTrials.gov and will be published in appropriate clinical journal upon completion.
This study is completed, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
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Dartmouth-Hitchcock Medical Center