A primary goal is to relate EEG based rsFC to changes in excitability of the brain. Since the excitability recorded with the MEPs reflect antiepileptic drug effects [1,2] it is assumed that these changes will be more pronounced after withdrawal of…
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Source
Brief title
Condition
- Seizures (incl subtypes)
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary study parameter is that changes in excitability of the brain
studied with MEPs evoked by TMS, are reflected in the EEG either as evoked
discharges or as increased rsFC.
Secondary outcome
A secondary endpoint is the rejection of the null-hypothesis that the
excitability of the brain is not increased in the condition without the use of
AEDs compared to the condition that the patient is on the steady-state
maintenance doses of AEDs as prescribed.
Background summary
Transcranial magnetic stimulation (TMS) is a non-invasive method that can be
used to stimulate the human brain. Due to recent developments, it is now
possible to record TMS and EEG simultaneously. In this way, the changes in
brain activity induced by TMS can be recorded with EEG. It has been shown that
TMS in relation with the measurement of Motor Evoked Potentials (MEPs) reflects
the changes in excitability of the brain. MEPs, however, are highly variable in
between and within subjects. The simultaneously recorded EEG might be an
alternative to measure the excitability of the brain. Furthermore, it has been
shown that TMS while recording simultaneously EEG (TMS-EEG) is a new research
field to measure directly drug effects on brain excitability.
Study objective
A primary goal is to relate EEG based rsFC to changes in excitability of the
brain. Since the excitability recorded with the MEPs reflect antiepileptic drug
effects [1,2] it is assumed that these changes will be more pronounced after
withdrawal of anti-epileptic drugs (AEDs). Secondary objectives: The secondary
goal is to assess TMS-EEG recordings systematically with regard to abnormal
discharges and the diagnostic value of these discharges.
Study design
To study the excitability of the brain in relation to medication for patients
with focal epilepsy (n=103). The AEDs as prescribed will be tapered according
to standard clinical procedures during their pre-surgical video-EEG
examination. TMS-EEG will be applied before withdrawal of AEDs, while the
patient is on the usual maintenance of AEDs, before the start of the video-EEG
session and after withdrawal of AEDs, at the end of the session. For each of
the conditions it will be investigated whether the EEG reflects abnormal
discharges and whether these findings are of diagnostic and/or localizing value
and whether rsFC has changed after withdrawal of AEDs. For comparison, the
excitability of the brain as measured in each condition, before and after
withdrawal of AEDs by Motor Threshold (rMT) measurements (which is the gold
standard) will be related to the changes in rsFC.
Study burden and risks
TMS is a widely used non-invasive brain stimulation technique, based on the
principle of electromagnetic induction. In the current study, healthy
participants and patients will be stimulated with a protocol that falls within
the safety guidelines, i.e. high-frequency stimulation is not used [3]. It is
not expected that epileptic seizures are induced in healthy volunteers and
there is a slight chance that seizures are induced in epilepsy patients.
However, when patients with a lowered cortical excitability threshold (e.g., as
a consequence of anti-epileptic drug treatment) are stimulated, the risk of
inducing habitual spells or even a seizure might be increased. Such a case will
be managed by the neurologist/clinical neurophysiologist and in epilepsy
specialised care takers according to the protocols in place at Kempenhaeghe.
Sterkselseweg 61
5591 VE Heeze
NL
Sterkselseweg 61
5591 VE Heeze
NL
Listed location countries
Age
Inclusion criteria
* Patients and healthy volunteers need to be 18 years or older and should be able to perceive magnetic stimulation, i.e. do not fulfil any of the exclusion criteria as mentioned in section 4.3.
* The patients included should be candidate for a video-EEG recording as part of their pre-surgical investigations.
* The decision for withdrawal of AEDs is a clinical decision, which is not influenced by the protocol requirements of this study.
* The patients included all are selected to have a pre-surgical simultaneous EEG and fMRI investigation.
Exclusion criteria
* Serious head trauma or brain surgery
* Large or ferromagnetic metal parts in the head (except for a dental wire)
* Implanted cardiac pacemaker or neurostimulator
* Pregnancy
* Skin diseases at intended electrode sites (EMG, EEG, TMS)
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL57098.091.16 |