Stimulation of the Thalamus for Arousal Restoral in Temporal Lobe Epilepsy

NCT ID: NCT04897776

Last Updated: 2025-12-26

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

5 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-10-31

Study Completion Date

2025-07-15

Brief Summary

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The goal is to provide a novel therapeutic option for temporal lobe epilepsy patients when focal impaired awareness seizures cannot be stopped by medications, surgical or laser ablation, or by neurostimulation. The goal is restore consciousness when seizures cannot be stopped. If successful, addition of bilateral thalamic stimulation to existing responsive neurostimulation to rescue consciousness would greatly alter clinical practice and patient outcomes.

Importantly, previous approaches aim to stop seizures, whereas this study aims to use thalamic stimulation to improve a major negative consequence when seizures cannot be stopped. The potential impact extends beyond temporal lobe epilepsy to other seizure types, and may also extend more broadly to inform treatment of other brain disorders associated with impaired consciousness and cognition.

Detailed Description

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Impaired consciousness during seizures has a major negative impact on quality of life for people with epilepsy. Consequences include risk of motor vehicle accidents, drowning, poor work and school performance, and social stigmatization. Impaired ictal/postictal arousal may also compromise breathing leading to sudden unexpected death in epilepsy. Although the primary goal of epilepsy care is to stop seizures, restoring conscious awareness in patients whose seizures cannot be stopped (by medications, surgery or deep brain stimulation) could significantly improve outcome. Disorders of consciousness other than epilepsy have long been known to arise from dysfunction of subcortical-cortical arousal circuits. Deep brain stimulation (DBS) of the thalamic intralaminar central lateral nuclei (CL) is a promising approach to restore conscious arousal currently being trialed for chronic disorders of consciousness. Recent neuroimaging and EEG studies have shown that transient impaired consciousness in temporal lobe epilepsy (TLE) seizures also depends on subcortical-cortical arousal including thalamic CL. Translational studies from this research group further demonstrate depressed CL function in limbic seizures, and most importantly that thalamic CL stimulation has the potential to restore physiological and behavioral arousal in the ictal and postictal periods. DBS treatment of epilepsy has advanced rapidly with FDA approval of responsive neurostimulation (RNS, NeuroPace) and thalamic anterior nucleus stimulation (Medtronic). Investigational devices such as the Medtronic Summit RC+S provide a unique opportunity for responsive stimulation of up to four separate brain regions, enabling conventional sites such as hippocampus (HC) to be combined with innovative targets such as thalamic CL. Meanwhile, collaborators Mayo Clinic have developed the Epilepsy Personal Assistant Device (EPAD), a custom application running on a hand-held device with bi-directional communication with the RC+S. The EPAD will enable cloud-based data storage, seizure diaries, and automatic behavioral tests. Therefore, the goal is to develop and pilot test the feasibility and safety of bilateral thalamic CL stimulation using RC+S to restore conscious arousal in TLE seizures which are not stopped by conventional responsive neurostimulation, offering hope to greatly improve quality of life in these patients.

Conditions

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Epilepsy, Temporal Lobe

Keywords

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Thalamic Stimulation Hippocampal Stimulation Awareness Ictal Awareness Post-ictal Awareness Consciousness Temporal Lobe Epilepsy Epilepsy Quality of Life Cognition Neurostimulation Deep Brain Stimulation Responsive Neurostimulation Intralaminar Thalamus Thalamic Central Lateral Nucleus Device Behavioral Assessment

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

CROSSOVER

After controlling for implant effects and hippocampal stimulation, there will be a period of blinding for thalamic stimulation. Physician and patient will not know which seizures during this period receive stimulation or sham stimulation. The primary outcome measure will be comparing behavioral awareness scores during this period, sham stimulation compared to therapeutic stimulation.
Primary Study Purpose

TREATMENT

Blinding Strategy

DOUBLE

Participants Investigators

Study Groups

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Therapeutic Thalamic Stimulation

Four months post implant, the neurostimulator device will provide patients with hippocampal stimulation for all seizures. For seizures longer than five seconds, thalamic stimulation will be administered at a therapeutic level established based on the physician's evaluation and patient specific parameters established at a previous visit. This will occur in half of the seizures the patient experiences and will be randomly assigned during this phase of the study.

If no benefit is experienced during this phase of the study, patients may participate in an optional randomized CL stimulation phase for an additional four months.

Group Type EXPERIMENTAL

Central Thalamic Stimulation

Intervention Type DEVICE

Stimulation of the bilateral thalamic CL is a promising approach in human patients to improve conscious arousal. To restore conscious arousal by stimulation of the thalamic intralaminar CL it is necessary to provide bilateral stimulation, placing one lead in each thalamus. Bilateral thalamic CL stimulation was shown previously to improve human conscious arousal and is based on existing research in patients with disorders of consciousness.

Hippocampal Stimulation

Intervention Type DEVICE

The hippocampus has been a target for brain stimulation for seizure reduction in epilepsy. While the efficacy of HC stimulation varies considerably among different studies, the surgical procedure and therapeutic electrical stimulation are well tolerated by patients, with few peri-operative complications being reported, and histopathologic analysis not revealing a difference between stimulated and non-stimulated hippocampal tissue (Han et al. 2014)

Non-Therapeutic Thalamic Stimulation

Four months post implant, the neurostimulator device will provide patients with hippocampal stimulation for all seizures. For seizures longer than five seconds, thalamic stimulation will be administered at below therapeutic threshold to control for implant and placebo effects. This will occur in half of the seizures the patient experiences and will be randomly assigned during this phase of the study.

If no benefit is experienced during this phase of the study, patients may participate in an optional randomized CL stimulation phase for an additional four months.

Group Type SHAM_COMPARATOR

Hippocampal Stimulation

Intervention Type DEVICE

The hippocampus has been a target for brain stimulation for seizure reduction in epilepsy. While the efficacy of HC stimulation varies considerably among different studies, the surgical procedure and therapeutic electrical stimulation are well tolerated by patients, with few peri-operative complications being reported, and histopathologic analysis not revealing a difference between stimulated and non-stimulated hippocampal tissue (Han et al. 2014)

Interventions

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Central Thalamic Stimulation

Stimulation of the bilateral thalamic CL is a promising approach in human patients to improve conscious arousal. To restore conscious arousal by stimulation of the thalamic intralaminar CL it is necessary to provide bilateral stimulation, placing one lead in each thalamus. Bilateral thalamic CL stimulation was shown previously to improve human conscious arousal and is based on existing research in patients with disorders of consciousness.

Intervention Type DEVICE

Hippocampal Stimulation

The hippocampus has been a target for brain stimulation for seizure reduction in epilepsy. While the efficacy of HC stimulation varies considerably among different studies, the surgical procedure and therapeutic electrical stimulation are well tolerated by patients, with few peri-operative complications being reported, and histopathologic analysis not revealing a difference between stimulated and non-stimulated hippocampal tissue (Han et al. 2014)

Intervention Type DEVICE

Eligibility Criteria

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Inclusion Criteria

1. All patients will have evidence of mesial temporal seizures based on either

1. Intracranial EEG monitoring with mesial temporal lobe onset
2. or scalp EEG evidence of temporal lobe seizures and other evidence of mesial temporal lobe epilepsy.
2. Subject's seizure focus, based upon clinical history, semiology, electroencephalographic (EEG) findings, and/or neuroimaging, shall demonstrate bilateral or unilateral mesial temporal lobe epilepsy, and subject shall not be good candidate for surgical resection.
3. Focal epilepsy with disabling seizure counts mean of ≥ 2 per month. Disabling seizures are those with significant negative impact on the patient's life, involving impaired conscious awareness. Seizures counts will be based on patient's self-report. Note that patient's typically have more disabling seizures than they are able to self-report, and may also have additional non-disabling seizures in addition to the disabling seizures required for enrolment.

i. Mean seizure count ≥ 2 per month is established initially for the preceding 6 months at time of Enrollment, using seizures reported by the patient and/or caregiver. Seizures during EMU admissions are not included.
4. Drug resistance to at least two antiseizure medications (ASM) with adequate dose and duration.
5. Subject is willing to remain on stable ASM from the Baseline phase through the end of the Randomized CL Stimulation phase. Stable is defined as same medications, but dose adjustments are allowed within accepted therapeutic ranges. Also, short-term benzodiazepines allowed for acute seizure worsening as in prior studies.
6. Apart from epilepsy, subject must be medically and neurologically stable and must have no other medical condition in the opinion of the treating physician that would preclude the patient from participation. This could include conditions like severe ischemic cardiac disease, progressive dementia or other disorders that could affect surgical eligibility or compliance.
7. The local treating epilepsy center has recommended the patient for brain stimulation therapy on clinical grounds and without reference to this protocol.
8. Age 18 to 75 years, inclusive, at time of consent.
9. Ability and willingness to provide informed consent and participate in the study protocol.
10. Subject can interpret and to respond, in accordance with the study protocol, to the advisory indicators provided by the device. This includes the ability to recharge the device.
11. Subject has seizures that are distinct, stereotypical events that can be reliably counted by the patient or caregiver.
12. Subject can reasonably be expected to maintain a seizure diary alone or with the assistance of a competent individual.
13. Subject can complete regular office visits and telephone appointments in accordance with the study protocol requirements.
14. A female subject must have a negative pregnancy test and if sexually active, must be using a reliable form of birth control for the duration of the trial, be surgically sterile, or be at least two years post-menopausal.
15. Subject has been informed of his or her eligibility for resective surgery as a potential alternative to the study, if such surgery is a reasonable option.
16. Subject speaks and reads English.
17. Subject's anatomy will permit implantation of the Medtronic Investigational Summit RC+S generator within 20 mm of the skin surface.
18. Subject is capable of completing the proposed neuropsychology evaluation and will score no lower than 2 standard deviations below average on the Wechsler Adult Intelligence Scale.

Exclusion Criteria

1. Subject has a contraindication to magnetic resonance imaging.
2. Subject has a significant substance abuse history (alcohol, prescription, or illicit medications) within the preceding two years with evidence of impact on daily function.
3. Subject participated in another drug or device trial within the preceding 30 days.
4. Demonstrates that they fulfill criteria on any of the three subscale of the SCID-5-PD for borderline, antisocial, or narcissistic personality disorders and these criteria are then corroborated by psychiatric interview, and that this would significantly affect participation in the study.
5. Suicide attempt in the past year.
6. Arrest for assault or possession of drugs or weapons with intent to sell/distribute in the past year.
7. Subject is implanted with pacemaker, implantable cardiac defibrillator, cardiac management product, or a medical device that interferes with the RC+S device. This includes, but is not limited to, direct brain neurostimulators, spinal cord stimulators, vagus nerve stimulators (VNS), and cochlear implants. Patients with a vagus nerve stimulator implanted but turned off through the duration of the study may be enrolled, provided their clinical status has been stable for at least one month with VNS turned off. Alternatively, patients with a VNS may have the previously disabled VNS removed at time of surgery to implant the Medtronic RC+S.
8. Subject has confirmed active diagnosis of psychogenic or non-epileptic seizures.
9. Subject has confirmed diagnosis of primary generalized seizures.
10. Subject has experienced unprovoked status epilepticus in the preceding year.
11. Subject has had therapeutic surgery to treat epilepsy that may interfere with electrode placement.
12. Subject has progressive neurological disorder or medical condition that would prevent the participant to fully participate in the clinical trial.
13. Subject has severe chronic pulmonary disease or cardiac disease, local, systemic acute or chronic infectious illness.
14. Subject is on anticoagulants and is unable to discontinue them peri-surgically, as required by the neurosurgeon or Investigator.
15. Subject has significant platelet dysfunction from medical conditions or medications (including, particularly, aspirin or sodium valproate). If platelet dysfunction is suspected, subject can be enrolled only if a hematologist, the Investigator, and the neurosurgeon judge it to be advisable.
16. Subject is ineligible for cranial surgery.
17. Subject scores equal to or below a full-scale intelligence quotient (FSIQ) of 70, as measured by the Wechsler Adult Intelligence Scale.
18. Pregnancy.
19. Any condition or finding that in the judgement of the site PI significantly increases risk or significantly reduces the likelihood of benefit from participation in the study.
Minimum Eligible Age

18 Years

Maximum Eligible Age

75 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Mayo Clinic

OTHER

Sponsor Role collaborator

Dartmouth-Hitchcock Medical Center

OTHER

Sponsor Role collaborator

National Institute of Neurological Disorders and Stroke (NINDS)

NIH

Sponsor Role collaborator

Yale University

OTHER

Sponsor Role lead

Responsible Party

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Hal Blumenfeld, MD, PhD

Professor of Neuroscience and of Neurosurgery

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Hal Blumenfeld, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Yale University

Barbara Jobst, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Dartmouth-Hitchcock Medical Center

Gregory Worrell, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

Mayo Clinic

Locations

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Yale New Haven Hospital

New Haven, Connecticut, United States

Site Status

Mayo Clinic

Rochester, Minnesota, United States

Site Status

Dartmouth-Hitchcock Medical Center

Lebanon, New Hampshire, United States

Site Status

Countries

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United States

References

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Han CL, Hu W, Stead M, Zhang T, Zhang JG, Worrell GA, Meng FG. Electrical stimulation of hippocampus for the treatment of refractory temporal lobe epilepsy. Brain Res Bull. 2014 Oct;109:13-21. doi: 10.1016/j.brainresbull.2014.08.007. Epub 2014 Sep 6.

Reference Type BACKGROUND
PMID: 25200252 (View on PubMed)

Geller EB, Skarpaas TL, Gross RE, Goodman RR, Barkley GL, Bazil CW, Berg MJ, Bergey GK, Cash SS, Cole AJ, Duckrow RB, Edwards JC, Eisenschenk S, Fessler J, Fountain NB, Goldman AM, Gwinn RP, Heck C, Herekar A, Hirsch LJ, Jobst BC, King-Stephens D, Labar DR, Leiphart JW, Marsh WR, Meador KJ, Mizrahi EM, Murro AM, Nair DR, Noe KH, Park YD, Rutecki PA, Salanova V, Sheth RD, Shields DC, Skidmore C, Smith MC, Spencer DC, Srinivasan S, Tatum W, Van Ness PC, Vossler DG, Wharen RE Jr, Worrell GA, Yoshor D, Zimmerman RS, Cicora K, Sun FT, Morrell MJ. Brain-responsive neurostimulation in patients with medically intractable mesial temporal lobe epilepsy. Epilepsia. 2017 Jun;58(6):994-1004. doi: 10.1111/epi.13740. Epub 2017 Apr 11.

Reference Type BACKGROUND
PMID: 28398014 (View on PubMed)

Salanova V, Witt T, Worth R, Henry TR, Gross RE, Nazzaro JM, Labar D, Sperling MR, Sharan A, Sandok E, Handforth A, Stern JM, Chung S, Henderson JM, French J, Baltuch G, Rosenfeld WE, Garcia P, Barbaro NM, Fountain NB, Elias WJ, Goodman RR, Pollard JR, Troster AI, Irwin CP, Lambrecht K, Graves N, Fisher R; SANTE Study Group. Long-term efficacy and safety of thalamic stimulation for drug-resistant partial epilepsy. Neurology. 2015 Mar 10;84(10):1017-25. doi: 10.1212/WNL.0000000000001334. Epub 2015 Feb 6.

Reference Type BACKGROUND
PMID: 25663221 (View on PubMed)

Schiff ND, Giacino JT, Kalmar K, Victor JD, Baker K, Gerber M, Fritz B, Eisenberg B, Biondi T, O'Connor J, Kobylarz EJ, Farris S, Machado A, McCagg C, Plum F, Fins JJ, Rezai AR. Behavioural improvements with thalamic stimulation after severe traumatic brain injury. Nature. 2007 Aug 2;448(7153):600-3. doi: 10.1038/nature06041.

Reference Type BACKGROUND
PMID: 17671503 (View on PubMed)

Kremen V, Brinkmann BH, Kim I, Guragain H, Nasseri M, Magee AL, Pal Attia T, Nejedly P, Sladky V, Nelson N, Chang SY, Herron JA, Adamski T, Baldassano S, Cimbalnik J, Vasoli V, Fehrmann E, Chouinard T, Patterson EE, Litt B, Stead M, Van Gompel J, Sturges BK, Jo HJ, Crowe CM, Denison T, Worrell GA. Integrating Brain Implants With Local and Distributed Computing Devices: A Next Generation Epilepsy Management System. IEEE J Transl Eng Health Med. 2018 Sep 26;6:2500112. doi: 10.1109/JTEHM.2018.2869398. eCollection 2018.

Reference Type BACKGROUND
PMID: 30310759 (View on PubMed)

Related Links

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Other Identifiers

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1UG3NS112826-01

Identifier Type: NIH

Identifier Source: secondary_id

View Link

2000030289

Identifier Type: -

Identifier Source: org_study_id