Human Thalamus in Propagation of Temporal Lobe Seizures and Memory Formation

N/AEnrolling By InvitationNCT07226908

Stanford University100 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

100

Conditions

Epilepsy

Interventions

Cognitive experimentOTHER

Record brain activity during memory encoding

Electrical stimulation of the brainOTHER

Measure accuracy and reaction time during cognitive tasks

Eligibility

Sex: ALLMin age: 18 YearsMax age: 65 Years

Medical Language ↔ Plain English

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

Locations (1)

Stanford Hospital

Stanford, California, United States

Outcomes

Primary Outcomes

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).

Time frame: 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.

Time frame: 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.

Time frame: 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.

Time frame: 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.

Data from ClinicalTrials.gov

This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.