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Cerebral Metabolic Changes Associated With Thalamic Stimulation

Phase 3
Terminated
Conditions
Epilepsy
Interventions
Procedure: Positron Emission Tomography (PET) Scan
Procedure: Magnetic Resonance Imaging (MRI)
Other: Neuropsychological Testing
Registration Number
NCT01141764
Lead Sponsor
The Hospital for Sick Children
Brief Summary

The purpose of this research study is to evaluate the brain circuits function and circuits involved in the mechanism of thalamic DBS in patients with medically refractory epilepsy.

Detailed Description

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus in patients with medically refractory epilepsy has been shown to be efficacious. Studies have estimated a 46-76% reduction in seizures relative to the baseline. However, the exact anatomic circuitry involved in the mechanism of DBS in epilepsy remains unknown. Positron emission tomography (PET) studies can provide clues to the metabolic activity associated with DBS activation. In our study, patients will be scanned with their DBS electrodes turned "on" and "off". PET data captured during these two distinct states may show characteristic differences in cerebral glucose metabolism and modulatory effects of surrounding cerebral structures, thus providing clues to how DBS works to prevent seizures.

Recruitment & Eligibility

Status
TERMINATED
Sex
All
Target Recruitment
4
Inclusion Criteria
  • 18-85 years old
  • currently have DBS implanted for medically refractory epilepsy
  • Women of childbearing age will be required to use established contraceptive methods while enrolled in the study.
Exclusion Criteria

Patients who:

  • are < 18 years of age or > 85 years of age
  • are medically unstable
  • are women who are potentially pregnant, pregnant or nursing
  • have had PET imaging within 1 year.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Study GroupMagnetic Resonance Imaging (MRI)In our study, patients will be scanned with their DBS electrodes turned "on" and "off". Participation involves undergoing 2 separate PET scans on 2 separate days. The MRI and neuropsychological tests will either be performed on the same day as one of the PET scans or on a separate day. Procedures performed in this study are not part of the standard management of epilepsy.
Study GroupNeuropsychological TestingIn our study, patients will be scanned with their DBS electrodes turned "on" and "off". Participation involves undergoing 2 separate PET scans on 2 separate days. The MRI and neuropsychological tests will either be performed on the same day as one of the PET scans or on a separate day. Procedures performed in this study are not part of the standard management of epilepsy.
Study GroupPositron Emission Tomography (PET) ScanIn our study, patients will be scanned with their DBS electrodes turned "on" and "off". Participation involves undergoing 2 separate PET scans on 2 separate days. The MRI and neuropsychological tests will either be performed on the same day as one of the PET scans or on a separate day. Procedures performed in this study are not part of the standard management of epilepsy.
Primary Outcome Measures
NameTimeMethod
Areas of the brain with low activitywithin 30 days of enrollment in the study

This measure will be based on the results of two PET scans done on separate days. The stimulator will be "on" during the first PET image acquisition and "off" during the second PET image acquisition.

Secondary Outcome Measures
NameTimeMethod
Brain Abnormalitieswithin 30 days of enrollment in the study

One Magnetic Resonance Imaging (MRI) scan will be used to take detailed images of the brain and detect whether there are any abnormalities.

Ability to learn and understandwithin 30 days of enrollment in the study

One session of neuropsychological testing will be done in order to assess the subject's ability to learn and understand.

Trial Locations

Locations (2)

Toronto Western Hospital

🇨🇦

Toronto, Ontario, Canada

The Hospital for Sick Children

🇨🇦

Toronto, Ontario, Canada

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