Magnetoencephalography in Absence Seizures

NCT ID: NCT00884351

Last Updated: 2017-07-02

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

Total Enrollment

5 participants

Study Classification

OBSERVATIONAL

Study Start Date

2009-04-15

Study Completion Date

2011-06-15

Brief Summary

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Background:

* An absence seizure is a type of seizure that usually begins in childhood and goes away by early adulthood. Scientists do not yet know where absence seizures begin in the brain. Some evidence suggests that these seizures begin in the thalamus, a structure deep in the brain, but other studies suggest that they begin in the frontal cortex, at the front part of the brain.
* Magnetoencephalography is a type of brain scanning procedure that is useful in determining information about what happens to the brain during epileptic seizures. Understanding where absence seizures come from may help doctors find new treatments for them.

Objectives:

* To gain a better understanding of which parts of the brain are affected in absence seizures.

Eligibility:

* Patients 7 to 35 years of age who have been diagnosed with absence seizures.

Design:

* Procedures are for research purposes only, not to diagnose or treat a particular medical condition.
* Two outpatient visits to the National Institutes of Health Clinical Center: evaluation and scanning.
* Researchers will evaluate potential participants with a medical history, physical examination, and electroencephalography (EEG). These tests will be performed under another protocol, 01-N-0139.
* Patients will undergo magnetoencephalography (MEG) and magnetic resonance imaging (MRI) of the brain. The study procedures will be performed one time; however, an MEG or MRI scan may need to be repeated for technical reasons. Researchers will not do more than two MEG or MRI scans.
* The MEG will record very small magnetic field changes produced by the activity of the brain. An EEG will be recorded at the same time as the MEG.
* The MRI will use a magnetic field to take pictures of the inside of the brain.
* The MEG will take 3 hours to complete (2 hours for preparation, 1 hour in the scanner). The MRI will take approximately 1 hour.

Detailed Description

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Objective:

This protocol will test the hypothesis that the 3-Hz spike-wave discharges seen in absence epilepsy originate in the thalamus. We will use an emerging modality, magnetoencephalograpy (MEG), to test this hypothesis.

Study Population:

33 patients with absence seizures.

Design:

This is a non-invasive imaging study that involves a 275-channel whole head MEG recording and a structural MRI for co-registration of MEG data.

Outcome Measure:

The primary outcome measure is the source localization of spike-wave discharges on magnetoencephalography.

Conditions

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Seizures

Study Design

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Study Time Perspective

PROSPECTIVE

Eligibility Criteria

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Inclusion Criteria

1. Age 7-35
2. Absence of seizures based on clinical and electroenecephalography data. Patients who have other seizure types (myoclonic, generalized tonic-clonic) in addition to absence seizures may be included.
3. Patients who have other neurologic disorders may be included, as long as they are able to consent/assent.

Exclusion Criteria

1. Contraindications to MEG studies (Dental braces, permanent retainers, metal dental caps/crowns/fillings)
2. Contraindications to MRI studies (such as pacemakers, cochlear devices, surgical clips, metallic implants, orthopedic pins, shrapnel, permanent eyeliner, vagus nerve stimulator)
3. Claustrophobia or anxiety disorders exacerbated by MRI
4. Pregnancy
5. Inability to provide consent/assent
Minimum Eligible Age

7 Years

Maximum Eligible Age

35 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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National Institute of Neurological Disorders and Stroke (NINDS)

NIH

Sponsor Role lead

Locations

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National Institutes of Health Clinical Center, 9000 Rockville Pike

Bethesda, Maryland, United States

Site Status

Countries

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United States

References

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Avoli M, Gloor P. Role of the thalamus in generalized penicillin epilepsy: observations on decorticated cats. Exp Neurol. 1982 Aug;77(2):386-402. doi: 10.1016/0014-4886(82)90252-7. No abstract available.

Reference Type BACKGROUND
PMID: 7095066 (View on PubMed)

Bernasconi A, Bernasconi N, Natsume J, Antel SB, Andermann F, Arnold DL. Magnetic resonance spectroscopy and imaging of the thalamus in idiopathic generalized epilepsy. Brain. 2003 Nov;126(Pt 11):2447-54. doi: 10.1093/brain/awg249. Epub 2003 Aug 5.

Reference Type BACKGROUND
PMID: 12902313 (View on PubMed)

Castro-Alamancos MA. Neocortical synchronized oscillations induced by thalamic disinhibition in vivo. J Neurosci. 1999 Sep 15;19(18):RC27. doi: 10.1523/JNEUROSCI.19-18-j0005.1999.

Reference Type BACKGROUND
PMID: 10479720 (View on PubMed)

Other Identifiers

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09-N-0125

Identifier Type: -

Identifier Source: secondary_id

090125

Identifier Type: -

Identifier Source: org_study_id

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