Objective: This protocol will test the hypothesis that successful left hemisphere epilepsy surgery for children and adults improves abnormalities in the functional anatomy of language that may be associated with uncontrolled localization-related seizures. We will use an established modality, functional magnetic resonance imaging (fMRI), which has been used extensively for evaluation of patients with epilepsy, as our primary outcome measure, and an emerging modality, magnetoencephalography (MEG), as a secondary measure. We will explore methods of MEG data analysis for comparison with fMRI results.

Study Population:

150 patients with localization-related epilepsy who are surgical candidates

50 healthy volunteers.

Design: This is a non-invasive imaging study that will employ a test battery including standard neuropsychological tests, structural MRI, fMRI, and a 275-channel whole-head MEG recording, for evaluation of the functional anatomy of language. The test battery will be performed pre-operatively and at 12 months after surgery.

Main outcome measure: Measurement of the "laterality index" comparing left and right hemisphere regional activation on fMRI before and after surgery, in patients after left sided or right-sided surgery, and healthy controls.

Secondary outcome measure: Measurement of the "laterality index" comparing left and right hemisphere regional activation on MEG before and after surgery.

• INCLUSION CRITERIA FOR PATIENTS:

  1. Age 7-55
  2. Documentation of localization-related epilepsy based on clinical, neuropsychological and imaging criteria
  3. Failure of seizures to respond to adequate therapy with at least two standard antiepileptic drugs
  4. Willingness to be considered for surgery
  5. Fluency in English. Non-native speakers may be included if their fluency is equivalent to that of a native speaker.

INCLUSION CRITERIA FOR HEALTHY VOLUNTEERS:

1. Age 7-55
2. Willingness to participate in and complete the study
3. Right-handedness assessed by the Edinburg handedness inventory
4. Fluency in English

EXCLUSION CRITERIA FOR PATIENTS:

1. Contra-indications to MRI studies (such as pacemakers, cochlear devices, surgical clips etc. metallic implants, orthopedic pins, shrapnel, permanent eyeliner, vagus nerve stimulator)
2. Claustrophobia or anxiety disorders exacerbated by the MRI scanner
3. People with neurological or psychiatric disease or taking medications that would affect fMRI and MEG language studies
4. Pregnancy. All females of child bearing potential must have a negative test prior to MRI scanning
5. Patients on phenobarbital or chronic benzodiazepines

EXCLUSION CRITERIA FOR HEALTHY VOLUNTEERS:

1. Contra-indications MRI studies (metallic implants, recent orthopedic pins, cochlear implants, surgical clips, cardiac pacemakers and defibrillation devices, shrapnel, permanent eyeliner, vagus nerve stimulator)
2. Any medical condition or chronic medication that might affect fMRI or MEG language activation by affecting cerebral structure or function, such as diabetes, hypertension, antihypertensive medications, pyshcotropic agents.
3. Pregnancy. All females of child bearing potential must have a negative test prior to MRI scanning.