Human Thalamus in Propagation of Temporal Lobe Seizures and Memory Formation

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).

Study Overview

• Status: Enrolling by invitation
• Conditions: Epilepsy
• Intervention / Treatment: Other: Cognitive experiment; Other: Electrical stimulation of the brain

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94304
      • Stanford Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

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

Exclusion Criteria:

• Unable to provide informed consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Epilepsy Patients with Thalamic Electrode Implants; Patients will undergo cognitive testing and electrical stimulation experiments.	Other: Cognitive experiment; Record brain activity during memory encoding; Other: Electrical stimulation of the brain; Measure accuracy and reaction time during cognitive tasks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: National Institute of Neurological Disorders and Stroke (NINDS)
• Investigators: Principal Investigator: Josef Parvizi, MD PhD, Stanford University

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2024
• Primary Completion (Estimated): August 1, 2029
• Study Completion (Estimated): August 1, 2029

Study Registration Dates

• First Submitted: August 11, 2025
• First Submitted That Met QC Criteria: November 8, 2025
• First Posted (Actual): November 12, 2025

Study Record Updates

• Last Update Posted (Actual): November 12, 2025
• Last Update Submitted That Met QC Criteria: November 8, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: Intracranial Electroencephalography
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy; Therapeutics; Surgical Procedures, Operative; Electric Stimulation Therapy; Deep Brain Stimulation
• Other Study ID Numbers: 11354 (DAIDS ES); 1R01NS137650-01A1 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Once data collection and analysis for a Specific Aim is complete, we will share our data.
• IPD Sharing Time Frame: Within 2 years
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No