Electrochemical and Electrophysiological Study

NCT05273970 | Enrolling By Invitation

• 1 other identifier: STUDY00000295
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

This study will utilize computerized algorithms in combination with real-time intracranial neurophysiological and neurochemical recordings and microstimulation to measure cognitive and affective behavior in humans. Questionnaires or simple behavioral tasks (game-like tasks on a computer or an iPad) may also be given to additionally characterize subjects on related cognitive or affective components. Importantly, for the purposes of understanding the function of the human brain, neural activity can be recorded and probed (i.e. microstimulation) while subjects are performing the same computerized cognitive and affective tasks. These surgeries allow for the in vivo examination of human neurophysiology and are a rare opportunity for such research. The questionnaires and assessments proposed will provide insights into disorders (and anxiety, depression) and psychological status that we hope to understand in relation to the neurochemistry measures. They will also provide baseline information that may be used to characterize and group the population to further refine our understanding of the neural responses. In addition to computerized testing, we plan to characterize subjects' behavior on related cognitive or affective components. Some neuropsychological questionnaires, many of which are administered for clinical reasons, may also be given to patients and healthy control subjects. All patients undergoing epilepsy surgery or deep brain stimulation undergo a standard clinical neuropsychological battery to assess aspects of cognitive function. This is a regular aspect of their clinical assessment carried out prior to consideration for study inclusion. All participants are selected uniformly because they are undergoing surgery for intracranial electrode implantation. No particular ethnic group or population is targeted by or excluded from the study. Those to be considered for inclusion in the proposed study performing more than 2 standard deviations below the mean on any aspect of cognitive functioning as determined by standard preoperative neuropsychological testing will be excluded from the study.

Conditions

Medically Intractable Epilepsy; Cognition

Keywords

epilepsy monitoring; seizure localization; neurotransmitters; electrophysiological parameters; Electrochemical gradients; Fast Scan Cyclic Voltammetry; SEEG

Outcome Measures

Primary Outcomes (3)

• Neurotransmitter Concentration Fluctuation in Visual Memory

  Neurotransmitter concentrations will be recorded through Fast Scan Cyclic Voltammetric methods during cognitive psychological tasks for visual memory administered on a laptop.

  During Hospitalization - 1-2 weeks

• Neurotransmitter Concentration Fluctuation and Pupillary Diameter in Sustained Attention Tasks

  Neurotransmitter concentrations will be recorded through Fast Scan Cyclic Voltammetric methods and and pupillary diameter will be observe with a pupillometer during cognitive psychological tasks for sustained attention administered on a laptop.

  During Hospitalization - 1-2 weeks

• Neurotransmitter Concentration Fluctuation in Neuroeconomics Tasks

  Neurotransmitter concentrations will be recorded through Fast Scan Cyclic Voltammetric methods during cognitive psychological tasks for neuroeconomics administered on a laptop.

  During Hospitalization - 1-2 weeks

Study Arms (1)

Behavioral testing under intracranial monitoring

EXPERIMENTAL

Patients will undergo behavioral tasks while being monitored by intercranial electrodes

Other: Behavioral testing under intracranial monitoring

Interventions

Behavioral testing under intracranial monitoring OTHER

After standard of care surgery to implant the electrodes is complete and patients have have recovered satisfactorily from the procedure, they will be asked to perform some computer based tasks to answer questions about pretend financial decisions, pay attention to certain images, watch videos, look at images, listen to sounds, or move a joystick.

Behavioral testing under intracranial monitoring

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 to 80 years, inclusive.
• Patients who are candidates for electrode implantation due to pharmacologically intractable epilepsy, or other neurological/psychological disorders for which subdural electrode implantation may be clinically required for treatment.
• Patients competent to give informed consent/assent for the research protocol and parents of children under 18 who are competent to give informed consent on behalf of the child.
• Fluency in English (necessary for uniform cognitive testing).
• Committee approved candidates for brain surgery.
• Medications must be at stable doses for at least 1 month before surgery

You may not qualify if:

• Clinically significant cognitive dysfunction.
• Terminal illness associated with \<12 month survival.
• Contraindication to MRI imaging, e.g., morbid obesity, metallic devices such as cardiac pacemakers, some aneurysm clips, or shrapnel.
• Current pregnancy or pregnancy planned during the course of the study.
• Cognitive function less than 2 standard deviations below normal on preoperative neuropsychological testing

Sponsors & Collaborators

• University of Arizona: lead
• Arizona State University: collaborator
• Virginia Polytechnic Institute and State University: collaborator

Study Sites (1)

Banner - University Medical Center, Phoenix campus

Phoenix, Arizona, 85006, United States

Location

Study Officials

• Robert Bina, MD

  University of Arizona

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor - Neurosurgery

Model Details: Recordings will be obtained from intracranial electrodes placed for clinical or approved research purposes during neurosurgical procedures, and/or thereafter, while patients are followed in the epilepsy monitoring unit (EMU). Electrodes approved for human use may be placed on the cortex or within subcortical structures. Recordings may be obtained during passive conditions and task-based recordings designed to study particular regions of interest will be carried out in the EMU, as well as passive without task performance. Patients undergoing surgery for invasive functional brain mapping may also undergo electrical microstimulation in addition to neurophysiological recording. Stimulation is typically delivered in 2-5 second bursts (25-50 Hz, 0.3 ms pulse width, 1-15 mA). Recording and microstimulation may take place either intra-operatively and/or post-operatively in the EMU.

Study Record Dates

• First Submitted: February 28, 2022
• First Posted: March 10, 2022
• Study Start: September 7, 2022
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): February 1, 2027
• Last Updated: December 17, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Data will be available for ASU and VT from initiation of the project, all the way through data analysis.
• Access Criteria: Virginia Tech and ASU will have access to the de-identified data via encrypted email or the University of Arizona's REDCap EDM.

Locations

US (1)