Noninvasive Pre-surgical Evaluation of Patients With Focal Epilepsy and Establishment of a Normative Imaging Database

Summary

Objectives: The overall study objective is to compare the sensitivities and specificities of morphometric analysis techniques using structural MRI images based on pre- and postsurgical localization of epileptic foci in patients undergoing presurgical evaluation for medically refractory epilepsy. To carry out these analyses, we aim to establish an age-stratified normative imaging database using healthy volunteers. Additional objectives are to identify abnormal networks in these patients using resting state fMRI/EEG and MEG/EEG, and to use language and memory fMRI tasks to examine the effects of epileptogenic zones and surgery on cognitive function and the networks associated with these functions. Study population: 300 adults and children (age 8 and older) with uncontrolled focal epilepsy, and 200 age-stratified healthy volunteers. Design: A retrospective and prospective natural history study. Research procedures for patients in this study include neuropsychological testing and 1-4 MRI sessions during presurgical evaluation and an additional 1-3 MRI sessions and neuropsychological testing approximately 12 months post-operatively. Research testing (such as research neuropsychological tests or MRI scanning sequences) will be done during a visit for clinical testing whenever possible, likely reducing the number of required visits. Patients will also have optional MEG and 7T structural imaging. Data will also be obtained from patients who have already undergone epilepsy surgery if they had procedures as outlined in the protocol and are willing to share the data. Healthy volunteers will receive a subset of the pre-operative procedures for patients, requiring at least 3 visits. In order to ensure adequate data acquisition, subjects may be re-scanned up to three times for the portions of the study in which they participated, possibly requiring additional visits. Outcome measures: The main outcomes will be establishment of normative values for morphometric analysis methods in age-stratified normal controls, and comparison of the sensitivity and specificity of these measures to pre- and postsurgical localization of the epileptogenic zone. Secondary outcome measures will include determination of the sensitivity and specificity of source localization using MEG/EEG and resting state fMRI/EEG, and to evaluate changes in activation during rest, as well as language and memory fMRI tasks in patients pre- and postsurgically, to examine the effects of epileptogenic zones and surgery on cognitive function and the networks underlying these functions. ...

Description

Eligibility

Age range

8–120 years

Sex

All

Healthy volunteers

Yes

Interventions

• Device
  MRI

  MRI of the brain is routinely used to identify abnormal areas of cortex in patients with medically refractory epilepsy. MRI evaluations of brain may be performed at field strengths of 1.5T, 3T, and/or 7T, under conditions designated by the FDA as constituting nonsignificant risk.

• Device
  MEG

  MEG/EEG: Magnetoencephalography (MEG) is commonly used during epilepsy pre-surgical evaluations to help with localizing epileptic foci. MEG will be obtained as clinically indicated, usually in patients with unclear seizure focus localization who are undergoing presurgical evaluation, particularly when they have frequent interictal discharges on EEG. MEG records very small magnetic fields generated by the brain at rest, or in response to a task or to epileptic activity. Resting state MEG/EEG analysis will be used for research purposes only.

Location