Human Thalamus in Propagation of Temporal Lobe Seizures and Memory Formation

NCT07226908 | Enrolling By Invitation

• 2 other identifiers: 113541R01NS137650-01A1
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of the study is to examine how two key subregions of the human thalamus (ANT and PLV) are connected with other brain structures (Aim 1), how seizures involve the two thalamic subregions differently and how the map of cortico-thalamic ictal propagation matches the intrinsic connectivity maps identified in the same individuals (Aim 2), and the effect of ANT and PLV stimulations on memory formation (Aim 3).

Conditions

Epilepsy

Keywords

Intracranial Electroencephalography

Outcome Measures

Primary Outcomes (6)

• Cerebro-cerebral evoked potentials

  To map thalamocortical and corticothalamic causal effective connectivity, the study team will use the well-known method of repeated single electrical pulse stimulation with intracranial EEG. Study team will measure the amplitude and timing to first peak of cerebro-cerebral evoked potentials (CCEPs).

  During experiment up to 2 weeks

• fMRI BOLD activity

  To map thalamocortical and corticothalamic functional connectivity, he study team will obtain 8 runs of 6mins resting state fMRIs. Study team will measure the correlation of BOLD activity across voxels of interest.

  During experiment up to 2 weeks

• Epileptogenicity Index (EI)

  The study team will identify seizure onset zones (SOZs) using the measure of Epileptogenicity Index (EI) applied to data collected through intracranial EEG, and will label the SOZs as medial temporal lobe epilepsy (mTLE) versus nonmedial TLEs.

  During experiment up to 2 weeks

• Seizure propagation

  Seizure propagation to ANT and PLV will be examined through intracranial EEG data within individuals by measuring EI and the propagation latencies from SOZ to ANT and PLV recording sites will be noted.

  During experiment up to 2 weeks

• Coordinated activity across HPC and ANT

  Successful memory encoding is associated with coordinated activity across hippocampus (HPC) and ANT (i.e., high frequency activity in ANT locked to the phase of hippocampal theta). Using intracranial EEG data, the study team will follow traditional analyses of changes in power in the canonical EEG bands (e.g., 3-7 Hz, theta band, 40-150 Hz, high gamma, etc.) as well as computationally derived aperiodic features of the signal \[i.e., using the fitting oscillations \& one over f (FOOOF) function\]. Response onset latency of neural activity will determine with simultaneous recordings across HPC, ANT, and PLV how each ROI is engaged in time during a given experimental condition (i.e., encoding trials later recalled and trials not later recalled). We will also use validated methods of phase amplitude coupling (PAC) and intersite phase coherence (ISPC) to quantify cross regional relationships.

  During experiment up to 2 weeks

• Cognitive task performance

  In total, each patient will be asked to encode 200 words across the 5 sessions.

  During experiment up to 2 weeks

Study Arms (1)

Epilepsy Patients with Thalamic Electrode Implants

OTHER

Patients will undergo cognitive testing and electrical stimulation experiments.

Other: Cognitive experiment; Other: Electrical stimulation of the brain

Interventions

Cognitive experiment OTHER

Record brain activity during memory encoding

Epilepsy Patients with Thalamic Electrode Implants

Electrical stimulation of the brain OTHER

Measure accuracy and reaction time during cognitive tasks

Epilepsy Patients with Thalamic Electrode Implants

Eligibility Criteria

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

You may qualify if:

• No medical or surgical contraindication to electrode implantation
• Patient capable of understanding the scope of our project or signing informed consent independently

You may not qualify if:

• Unable to provide informed consent

Sponsors & Collaborators

• Stanford University: lead
• National Institute of Neurological Disorders and Stroke (NINDS): collaborator

Study Sites (1)

Stanford Hospital

Stanford, California, 94304, United States

Location

MeSH Terms

Conditions

Epilepsy

Interventions

Deep Brain Stimulation

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Surgical Procedures, Operative

Study Officials

• Josef Parvizi, MD PhD

  Stanford University

  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: Professor of Neurology and Neurological Sciences (Adult Neurology)

Study Record Dates

• First Submitted: August 11, 2025
• First Posted: November 12, 2025
• Study Start: September 1, 2024
• Primary Completion (Estimated): August 1, 2029
• Study Completion (Estimated): August 1, 2029
• Last Updated: November 12, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Within 2 years

Locations

US (1)