Continuous Thetaburst Stimulation for the Treatment of Refractory Epilepsy - Safety, Feasibility and Proof-of-concept

The purpose of this study is to investigate a novel stimulation protocol of repetitive transcranial magnetic stimulation (rTMS) for the treatment of unifocal neocortical epilepsy, namely continuous thetaburst stimulation (cTBS). As this is a pilot study, the primary endpoint is on safety and tolerability of the treatment. However, information on clinical efficacy and mechanism of action will also be collected.

Study Overview

• Status: Terminated
• Conditions: Epilepsies, Partial
• Intervention / Treatment: Device: continuous thetaburst stimulation

Detailed Description

1. Study design:

   This is an open label prospective pilot trial of continuous thetaburst stimulation (cTBS) in patients with unifocal neocortical epilepsy.

   The study comprises a 13-week period, consisting of 4 weeks baseline seizure frequency assessment, a one-week treatment period with baseline assessments on Monday (T0) and stimulation sessions from Tuesday to Friday (T1-T4), and an 8-week follow-up period with short-term assessments immediately after the final stimulation session on Friday afternoon (T4) and long-term assessments after 2 weeks (FU2) and 8 weeks (FU8).

2. Objectives:

   The primary objective is to assess the feasibility, safety and tolerability of cTBS in refractory epilepsy patients. The secondary objectives are to assess the clinical efficacy and associated mechanism of action of cTBS in unifocal neocortical epilepsy.

3. Rationale:

An open label prospective design allows to make a first estimate on the safety, feasibility and tolerability of cTBS in refractory epilepsy patients. There are currently no reports available of cTBS performed in epilepsy patients. The ultimate aim is to assess clinical efficacy of cTBS with regard to seizure frequency, but a feasibility and safety study is a prerequisite in order to achieve this goal.

• Study Type: Interventional
• Enrollment (Actual): 7
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Ghent, Belgium, 9000
    • University Hospital Ghent

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Refractory unifocal neocortical epilepsy with a well-defined ictal onset zone based on a standardized presurgical evaluation
• ≥ 4 seizures/month, for at least six months
• On a stable drug regimen for at least 2 months
• IQ >70
• Reliable completion of a seizure diary by patient or caretakers
• Therapeutic compliance in the past
• Informed consent signed

Exclusion Criteria:

• Pregnancy, short-term birth wish or childbearing age without adequate birth control
• History of psychogenic non-epileptic seizures
• Intracranial metal hardware (excluding dental filling): surgical clips, shrapnell, electrodes under the stimulation area
• Presence of pacemaker, implantable cardioverter-defibrillator (ICD), permanent medication pumps, cochlear implants or deep brain stimulation (DBS)

Patients with a vagus nerve stimulator are not excluded, provided that adequate distance between the coil and the implanted material can be maintained.

As the short duration of the study will not interfere with an ongoing presurgical evaluation and/or its eventual conclusion, the patients in the course of the evaluation or awaiting surgery are also eligible for inclusion.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: continuous thetaburst stimulation; Transcranial magnetic stimulation over the epileptogenic focus using a cTBS stimulation protocol.

Device: continuous thetaburst stimulation; On 4 consecutive days patients receive 5 cTBS trains with a 10min intertrain-interval. One cTBS train consists of 600 pulses delivered in bursts at theta frequency (200ms) during 40s. Each burst comprises 3 pulses at 50Hz. Focal stimulation occurs over the epileptogenic focus (EF), perpendicular to the local gyral geometry, using online neuronavigation. Stimulation intensity is set relative to the resting motor threshold (rMT) determined at baseline (80% rMT). Stimulation intensity is further adjusted to the coil-cortex distance at the EF with the following formula: adjusted MT% (AdjMT) = rMT + 2,7*(DEF-DM1) [DEF = distance over EF; DM1 = distance over M1]. If rMT exceeds the capacity of the stimulator output, stimulation intensity is 100% of maximal stimulator output (MSO).; Other Names: rTMS; cTBS

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Seizure induction	Induction of epileptic seizures during or in-between rTMS stimulation trains as a measure of safety	Throughout stimulation, 4 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Seizure diary	Self-reported seizure frequency throughout the study as a measure of clinical efficacy. Four separate seizure diaries are provided: Baseline period: 4 weeks prior to treatment; Treatment week: from monday to friday evening; Follow-up part 1: two weeks following the treatment week; Follow-up part 2: week 3 to week 8 following treatment Patients note down if the seizure was habitual, atypical or if it was an episode of uncertain etiology (eg. non-epileptic)	Throughout the study, lasting 13 weeks
Adverse events diary	Description of all experienced adverse event during the study as a measure of safety and tolerability.	Throughout the study, lasting 13 weeks
Number of interictal epileptiform discharges (IEDs) on hd-EEG	A 15min hd-EEG is recorded and IEDs are counted during acquisition. Comparison of number of IEDs between the different time points as a measure of clinical efficacy.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up), 2 weeks after stimulation and 8 weeks after stimulation (long-term follow-up)
Number of interictal epileptiform discharges (IEDs) on normal EEG	Fifteen min EEG with 21 scalp electrodes is recorded immediately before and following each stimulation session. Number of IEDs are counted and compared between pre- and post acquisition as a measure of clinical efficacy.	Throughout the study, lasting 13 weeks: assessment immediately before and after each treatment session
Cortical resting motor threshold (rMT)	Cortical resting motor threshold is determined using single-pulse TMS over the primary motor cortex (M1) (ipsilateral to epileptogenic focus). Motor-evoked potential (MEP) is measured over the first dorsal interosseus (FDI) of the contralateral hand. Using a threshold tracking tool (Adaptive PEST) the minimally required stimulation intensity that elicits an MEP of 50 microvolt is determined. RMT at different time points throughout the study is compared to assess the effect of the treatment on cortical excitability as a measure of mechanism of action.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up), 2 weeks after stimulation and 8 weeks after stimulation (long-term follow-up)
TMS-EEG evoked potentials (TEPs)	TMS-EEG evoked potentials are measured over the epileptogenic focus and the primary motor cortex by performing single-pulse TMS (100 consecutive pulses jittered around an interval of 5s) with continuous EEG acquisition. The EEG is processed in order to obtain quantitative and comparable TEPs measures that reflect cortical excitability. These TEP measures obtained at different time points throughout the study are compared to assess the effect of the treatment on cortical excitability as a measure of mechanism of action.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up), 2 weeks after stimulation and 8 weeks after stimulation (long-term follow-up)
Magnetic resonance imaging (MRI)	Resting-state functional MRI (rs-fMRI) is acquired at the four main time points of the study to assess the effects of treatment on functional connectivity as a measure of mechanism of action.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up), 2 weeks after stimulation and 8 weeks after stimulation (long-term follow-up)
High-density EEG (hd-EEG)	A 128-channel EEG for resting-state EEG acquisition is obtained at the four main time points of the study to assess the effects of treatment on functional connectivity as a measure of mechanism of action.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up), 2 weeks after stimulation and 8 weeks after stimulation (long-term follow-up)
Change in Montreal Cognitive Assessment score (MoCA)	Score ranging from 0 [worst cognitive state] to 30 [best cognitive state], with a score of 26 or higher reflecting normal cognitive function. Cognitive assessment as a measure of safety: comparison at different time points throughout the study using MoCA version 7, 7.2 and 7.3 respectively.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up) and 8 weeks after stimulation (long-term follow-up)
Change in Computerized Visual Searching Task (CVST)	A 24-figure task assessing mean trial time [the faster the better] and number of errors [the lower the better] Assessment of mental flexibility and information processing as a measure of safety: comparison at different time points throughout the study.	Throughout the study, lasting 13 weeks: baseline (before treatment), following final stimulation session (short-term follow-up), 2 weeks after stimulation and 8 weeks after stimulation (long-term follow-up)
Change in Quality of life in epilepsy-31 (QOLIE-31)	Questionnaire scoring quality of life (QoL) ranged from 0 [lowest QoL] to 100 [highest QoL] (with associated T-value per score) as a measure of well-being.	Throughout the study, lasting 13 weeks: baseline (before treatment) and 8 weeks after stimulation (long-term follow-up)
Change in Beck depression inventory (BDI-II)	Questionnaire scoring depression ranged from 0 to 63 as a measure of well-being.	Throughout the study, lasting 13 weeks: baseline (before treatment) and 8 weeks after stimulation (long-term follow-up)
Change in Positive affect negative affect schedule (PANAS)	Questionnaire scoring affect as a measure of well-being.	Throughout the study, lasting 13 weeks: baseline (before treatment) and 8 weeks after stimulation (long-term follow-up)
Change in State-trait anxiety inventory (STAI)	Questionnaire scoring anxiety as a state (now) or a trait (more generally) separately, ranged from 20 [less anxious] - 80 [more anxious] as a measure of well-being.	Throughout the study, lasting 13 weeks: baseline (before treatment) and 8 weeks after stimulation (long-term follow-up)
Change in Visual analogue scale (VAS) of general well-being	Score ranged from 0 [lowest well-being] to 100 [highest well-being] as a measure of well-being.	Throughout the study, lasting 13 weeks: baseline (before treatment) and 8 weeks after stimulation (long-term follow-up)
Change in Visual analogue scale (VAS) of tolerability of the treatment	Score ranged from 0 [absolutely tolerable] -100 [absolutely intolerable] as a measure of tolerability and feasibility.	Throughout the study: after each treatment session and at the end of the study (8 weeks after stimulation)

Collaborators and Investigators

• Sponsor: University Hospital, Ghent
• Investigators: Principal Investigator: Kristl Vonck, MD, PhD, University Hospital, Ghent

Publications and helpful links

General Publications

• Huang YZ, Edwards MJ, Rounis E, Bhatia KP, Rothwell JC. Theta burst stimulation of the human motor cortex. Neuron. 2005 Jan 20;45(2):201-6. doi: 10.1016/j.neuron.2004.12.033.
• Nyffeler T, Cazzoli D, Hess CW, Muri RM. One session of repeated parietal theta burst stimulation trains induces long-lasting improvement of visual neglect. Stroke. 2009 Aug;40(8):2791-6. doi: 10.1161/STROKEAHA.109.552323. Epub 2009 Jun 11.
• Sun W, Mao W, Meng X, Wang D, Qiao L, Tao W, Li L, Jia X, Han C, Fu M, Tong X, Wu X, Wang Y. Low-frequency repetitive transcranial magnetic stimulation for the treatment of refractory partial epilepsy: a controlled clinical study. Epilepsia. 2012 Oct;53(10):1782-9. doi: 10.1111/j.1528-1167.2012.03626.x. Epub 2012 Sep 5.
• Fregni F, Otachi PT, Do Valle A, Boggio PS, Thut G, Rigonatti SP, Pascual-Leone A, Valente KD. A randomized clinical trial of repetitive transcranial magnetic stimulation in patients with refractory epilepsy. Ann Neurol. 2006 Oct;60(4):447-55. doi: 10.1002/ana.20950.
• Theodore WH, Hunter K, Chen R, Vega-Bermudez F, Boroojerdi B, Reeves-Tyer P, Werhahn K, Kelley KR, Cohen L. Transcranial magnetic stimulation for the treatment of seizures: a controlled study. Neurology. 2002 Aug 27;59(4):560-2. doi: 10.1212/wnl.59.4.560.
• Cantello R, Rossi S, Varrasi C, Ulivelli M, Civardi C, Bartalini S, Vatti G, Cincotta M, Borgheresi A, Zaccara G, Quartarone A, Crupi D, Lagana A, Inghilleri M, Giallonardo AT, Berardelli A, Pacifici L, Ferreri F, Tombini M, Gilio F, Quarato P, Conte A, Manganotti P, Bongiovanni LG, Monaco F, Ferrante D, Rossini PM. Slow repetitive TMS for drug-resistant epilepsy: clinical and EEG findings of a placebo-controlled trial. Epilepsia. 2007 Feb;48(2):366-74. doi: 10.1111/j.1528-1167.2006.00938.x.
• Nyffeler T, Wurtz P, Luscher HR, Hess CW, Senn W, Pflugshaupt T, von Wartburg R, Luthi M, Muri RM. Repetitive TMS over the human oculomotor cortex: comparison of 1-Hz and theta burst stimulation. Neurosci Lett. 2006 Nov 27;409(1):57-60. doi: 10.1016/j.neulet.2006.09.011. Epub 2006 Oct 17.
• Goldsworthy MR, Pitcher JB, Ridding MC. The application of spaced theta burst protocols induces long-lasting neuroplastic changes in the human motor cortex. Eur J Neurosci. 2012 Jan;35(1):125-34. doi: 10.1111/j.1460-9568.2011.07924.x. Epub 2011 Nov 25.
• Carrette S, Boon P, Klooster D, Van Dycke A, Carrette E, Miatton M, Raedt R, Delbeke J, Meurs A, Vonck K. Continuous theta burst stimulation for drug-resistant epilepsy. Front Neurosci. 2022 Aug 17;16:885905. doi: 10.3389/fnins.2022.885905. eCollection 2022.

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2015
• Primary Completion (Actual): April 1, 2018
• Study Completion (Actual): September 1, 2018

Study Registration Dates

• First Submitted: August 24, 2015
• First Submitted That Met QC Criteria: December 16, 2015
• First Posted (Estimate): December 21, 2015

Study Record Updates

• Last Update Posted (Actual): February 15, 2022
• Last Update Submitted That Met QC Criteria: January 31, 2022
• Last Verified: January 1, 2022

More Information

Terms related to this study

• Keywords: treatment resistant; transcranial magnetic stimulation; partial epilepsy; unifocal neocortical; thetaburst stimulation
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy; Epilepsies, Partial; Drug Resistant Epilepsy
• Other Study ID Numbers: EC/2015/0596