Human Intracranial Electrophysiology

Overview

This study will enroll patients with epilepsy who are being evaluated for epilepsy surgery and have electrodes implanted in the brain and/or have electrodes on the scalp. Additionally, this study will recruit normal and online controls (participants who do not have epilepsy). Participants will be asked to participate in 1 to 2 (30-90 minutes) daily sessions designed to test aspects of human cognition such as memory, speech, language, feeling, movement, attention, sound perception, and emotions. Generally, this will involve working on a computer, looking at pictures or watching videos, and answering questions. Additionally, participants may be asked to be hooked up to additional equipment such as eye tracker, electrical stimulator, heart rate monitor, sweat monitor or other non-invasive equipment. The overall aim of this study is to use human intracranial electrophysiology (the recording of the electrical activity of the human brain) to study localization and function of the human brain.

Detailed description

This project aims to study the mechanisms of brain function by using Human Intracranial Electrophysiology (HIE) methods and is a continuation of the "Localization of Human Brain Function" study done at Dartmouth-Hitchcock Medical Center (DHMC). HIE refers to the recording of brain signals using electrodes which are surgically inserted into the human brain for the clinical purpose of localizing the origins of epileptic seizures.

Secondary to clinical goals, such patients with intracranial EEG electrodes can be safely recruited to participate in research studies, i.e. the research "piggybacks" on procedures that are performed strictly for a clinical purpose. Brain signals obtained using HIE methods during performance of specific tasks have unique properties rich with insight into the inner workings of the human brain. HIE methods can be used together with electrical brain stimulation (EBS) techniques to better understand relationship between brain and behavior. Furthermore, HIE methods can be recorded together with other non-invasive bio-physiological data streams such as pupillometry, electrodermal activity (EDA), cardiac monitoring, and respiratory monitoring to understand the relationship between the brain and many aspects of human physiology.

Interventions

• Other Memory Tasks
  Participants will be asked to view pictures and videos presented on a computer screen and will be asked to recall the details of presented pictures or videos sometime later.
• Other Attention/arousal tasks
  Participants will be asked to perform a continuous performance task, such as continuous addition of numbers. Additionally, participants may be presented with images and may be asked to rate the significance or arousal values for each image.
• Other Language tasks
  Participants will be asked to view pictures of actions or things and will be asked to name them. Participants may also be asked to read words or passages.
• Other Visuospatial tasks
  Participants will be asked to copy 3 dimensional designs or make judgements of angle size.
• Other Auditory Tasks
  Participants will be presented with short, approximately 8-minute clips of music from various genres ( i.e. classical, country, rock, etc.) with an attention task (modified sustained attention to response task) nested within each trial. Participants will receive approximately 8 music stimuli and 1 control stimulus (pink noise) twice over the course of two testing sessions ( 90 mins each). Additionally, participants will be asked to answer questions about their hearing, music preferences/training
• Procedure Brain Stimulation
  A brain stimulator will be used to understand new functions of the brain. Participants will be presented with pictures on a computer screen and may be asked to tell researchers what is seen or remembered by participants. As pictures are viewed by the participants, the brain stimulator may be activated, which would not be something that would be felt by an individual participant.
• Other Social Emotional Task
  Participants will be asked to view presented pictures and videos of people engaged in social interaction. Additionally, participants will be presented with the standardized tasks that are designed to help the researchers with understanding the nature of emotions. Some of these images may be emotionally disturbing. If participants are not comfortable viewing such images, they will be asked to refrain from participation in this study.
• Other Recording of facial expressions
  Some participants may be asked permission to record the video of their facial expressions during performance of a research task. Generally, this will include only research tasks investigating brain representation of social/emotional information. Automated analysis of facial expression may be used in certain experiments to provide information on experience of emotional states such as happiness and sadness related to the images being presented.
• Other Judgement/Impulsivity Task
  Certain study participants may be enrolled into research tasks designed to activate regions important for judgment and impulse control. These tasks will present participants with choices of varying monetary rewards and ask them to make judgements to measure one's tendency to prefer immediate over delayed rewards.

Primary outcome measures

• Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with memory. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with language. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with emotions. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with movement. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with attention and executive function. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Using scalp and intracranial EEG, measure changes in electrical activity of the human brain associated with sound perception. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]

Secondary outcome measures (4)

• The degree of correlation between the brain activation and respiratory activity. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• The degree of correlation between the brain activation and electrodermal activity. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Measure the degree of correlation between the brain activation and sweat variations. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]
• Measure the degree of correlation between the brain activation and cardiac physiology. [Time frame: Evaluated for each patient during monitoring period of approximately 2 weeks.]

Eligibility criteria

Patients with Intracranial EEG: Inclusion Criteria

• Patients must be age 18 years or older. There is no upper age limit.
• Patients must have a diagnosis of refractory epilepsy undergoing intracranial EEG recording for clinical purposes.

Patients with Intracranial EEG: Exclusion Criteria

• Patient has additional neurological condition (such as stroke or dementia) or a psychiatric condition (such as active psychosis or suicidal ideation) and are deemed inappropriate for the study
• Patients are not able to provide informed consent for any reason (e.g. encephalopathic, experiencing a seizure)

Patients with Scalp EEG: Inclusion Criteria

• Patients must be age 18 years or older. There is no upper age limit.
• Patients must have a probable diagnosis of epilepsy.

Patients with Scalp EEG: Exclusion Criteria

• Patient has additional neurological condition (such as stroke or dementia) or a psychiatric condition (such as active psychosis or suicidal ideation) and are deemed inappropriate for the study
• Patients are not able to provide informed consent for any reason (e.g. encephalopathic, experiencing a seizure)

Normal Controls: Inclusion Criteria

• Participants must be age 18 years or older. There is no upper age limit.
• Participants must be able to provide informed consent for themselves.

Normal Controls: Exclusion Criteria

• Determined not to be appropriate normal control for the study population

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Basic science

Study locations

United States · 1 center

• Dartmouth-Hitchcock Medical Center — Lebanon

Identifiers

NCT: NCT05529264 · STUDY02001606

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗