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Enrolling by invitationNCT06521437Updated Sep 12, 2025

Hippocampal Network Function in Epilepsy

An interventional study of TMS targeting the hippocampus indirectly via its network in Mesial Temporal Lobe Epilepsy, sponsored by University of Chicago. Enrolling by invitation at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-12.

Sponsored by University of Chicago · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
34
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

The aim of this pilot study is to understand hippocampal network function in mesial temporal lobe epilepsy (MTLE) and to test whether transcranial magnetic stimulation (TMS) targeting the network of the hippocampus can change hippocampal-dependent memory task performance and epileptic activity in people with (MTLE). Positive findings would implicate the hippocampal network as a source of these typical primary MTLE symptoms.

Subjects with a primary diagnosis of MTLE will be enrolled in a non-randomized, non-blinded pilot experiment to test target engagement and preliminary efficacy of a novel neurostimulation approach targeting the hippocampal network. At baseline, subjects will undergo neurocognitive testing for hippocampal-dependent memory and functional magnetic resonance imagining (fMRI) neuroimaging assessment of brain structure and task-dependent activity. They will also receive scalp-electroencephalography (EEG) to measure interictal epileptiform discharge (IED) frequency at baseline, and will complete a seizure diary for one month. They will then receive high-frequency repetitive TMS targeting an area of parieto-occipital cortex defined based on fMRI connectivity with the hippocampus measured at baseline. The baseline assessments will then be repeated, using an alternate form of the memory test. The investigators will analyze changes from baseline in memory task performance, fMRI activity of the hippocampal network, IED frequency, and reported seizure frequency.

Read the detailed description

The purpose of this pilot study is to investigate hippocampal network dysfunction associated with mesial temporal lobe epilepsy (MTLE) and to examine whether network-targeted transcranial magnetic stimulation (TMS) can affect hippocampal connectivity, cognitive performance, and epileptic activity observed in adult subjects with MTLE.

Subjects will be recruited through the University of Chicago Medicine Comprehensive Epilepsy Center and other local epilepsy centers. Subjects will complete up to 8 experimental sessions (1 baseline experiment/assessment, up to 5 TMS sessions, up to 2 post-treatment experiments/assessments), spread over a two-month period. During the baseline and post-treatment sessions, subjects will undergo electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). EEG will be utilized to examine interictal epileptiform discharge (IED) frequency at rest as well as task-related neural activity recorded from non-invasive scalp EEG electrodes at locations conforming to the International 10-20 positioning system with additional anterior temporal electrodes. MRI scanning procedures will take approximately 45 minutes and include native anatomical (MP-RAGE) as well as functional (EPI) sequences to assess hippocampal network function and task-related activity. During both, the EEG and MRI procedures, subjects will perform a memory task.

One month following the baseline session, subjects will return to the lab for up to 5 TMS intervention sessions. During the one-month period preceding TMS, subjects will complete a daily seizure diary to track baseline seizure frequency prior to the intervention. TMS parameters are determined based on the allowable dosage of TMS delivery, calculated based on published standards for experimental TMS protocols, and in accordance with standard operating procedures for TMS. Subjects will receive brief (\~2 to 40s) trains of repetitive TMS with long (>10s) inter-train intervals. Each train of repetitive TMS will include between 20 and 40 individual pulses delivered at frequencies hypothesized to have different effects on memory (e.g., in the theta range). Individual pulse intensity will be calibrated using the motor-threshold method. Post-treatment sessions will once again comprise EEG and fMRI procedures as described above. Following the post-treatment sessions, subjects will continue to complete a daily seizure diary for the next 30 days to track any changes to seizures following treatment. Pre- and post-stimulation data will be compared to assess effects of the intervention on memory performance, hippocampal network function, and epileptic activity.

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Conditions studied

  • Mesial Temporal Lobe Epilepsy
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In context

Lead sponsor

University of Chicago is the lead sponsor of 907 studies on the registry; 182 are open to participants now.

Of its 99 completed or terminated interventional studies of FDA-regulated products, 68 (69%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Diagnosis of (pharmacoresistant) MTLE
  • Age 18+ years old
  • Native English speakers
  • Normal or corrected-to-normal near and far vision
  • Stable antiepileptic drugs (AED) regimen (unchanged for at least 1 month)

Exclusion criteria

Exclusion criteria:

  • Diagnosis of neurological illness other than MTLE
  • Taking drugs that impair cognition other than anticonvulsive medication for the treatment of MTLE (e.g., antipsychotics or psychostimulants).
  • Children under the age of 18 years
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Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
34 participants (estimated)

Study arms

  • Experimental
    Experiment 1

    Subjects will be tested for baseline performance on a memory task while in an MRI scanner and with scalp EEG. Subjects will then receive multiple sessions, of repetitive transcranial magnetic stimulation. Post-treatment, baseline assessments will be repeated. Overall study period per subject: 2 months

    Device: TMS targeting the hippocampus indirectly via its network

Interventions

  • DeviceTMS targeting the hippocampus indirectly via its network

    Subjects will receive high-frequency repetitive TMS to a parieto-occipital location defined in each subject based on high resting-state fMRI connectivity with the hippocampus at baseline

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What researchers measure

Primary outcomes

  1. Epileptic activity (IEDs)

    Scalp EEG is used to measure IEDs, identified via clinical assessment and quantified

    Time frame: Measured at baseline and 1 day after stimulation

Secondary outcomes

  1. Memory task performance

    Subjects memorize word pairs and then attempt to recall the missing word given one item from each pair after a delay. Total number of words pairs recalled will be measured.

    Time frame: The memory task is administered at baseline and 1 day after the last stimulation session. Recall will be measured approximately 15 minutes after seeing the word pairs.

  2. fMRI connectivity of the hippocampal network

    Subjects will undergo MRI neuroimaging assessment of brain structure and resting-state function. The correlation between the hippocampus and parietal cortex will be measured.

    Time frame: First day of study (baseline session) and 1 day after last stimulation session.

  3. Seizure frequency reported in seizure diary

    Subjects will complete an online seizure diary daily. Number of daily seizures reported will be measured.

    Time frame: From the baseline session to 30 days following the post-treatment sessions

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Study locations

1 site
  • University of Chicago
    Chicago, Illinois 60637, United States
08

References and documents

Publications

  • Rossi S, Hallett M, Rossini PM, Pascual-Leone A; Safety of TMS Consensus Group. Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and research. Clin Neurophysiol. 2009 Dec;120(12):2008-2039. doi: 10.1016/j.clinph.2009.08.016. Epub 2009 Oct 14. PubMed 19833552 ↗

Individual participant data

Plan to share: No

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 12, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT06521437
Lead sponsor
University of Chicago
Responsible party
Sponsor
First posted
Jul 26, 2024
Start date
Jul 1, 2024
Primary completion
Dec 2028 (estimated)
Completion
Dec 2028 (estimated)
Last update
Sep 12, 2025

Study contacts

Joel Voss, PhD
principal investigator · University of Chicago

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

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