Cerebral Metabolic Changes Associated With Thalamic Stimulation

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.

Study Overview

• Status: Terminated
• Conditions: Epilepsy
• Intervention / Treatment: Procedure: Positron Emission Tomography (PET) Scan; Procedure: Magnetic Resonance Imaging (MRI); Other: Neuropsychological Testing

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.

• Study Type: Interventional
• Enrollment (Actual): 4
• Phase: Phase 3

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 1X8
      • The Hospital for Sick Children
    • Toronto, Ontario, Canada, M5T 2S8
      • Toronto Western Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Study Group; 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.

Procedure: Positron Emission Tomography (PET) Scan; The PET procedure consists of an intravenous injection of 18F-FDG followed by a 45-minute period of quiet resting. PET images will be acquired on an integrated PET/CT scanner. This process will be repeated with the stimulator "on" during the first PET image acquisition and "off" during the second PET image acquisition. "On" and "off" PET image acquisitions will be performed on two separate days.; Procedure: Magnetic Resonance Imaging (MRI); MRI will be performed on a 1.5T system, using a combination of different sequences including sagittal T1, coronal and axial T2, FLAIR and proton density and axial 3D T1 weighted images.; Other: Neuropsychological Testing; On the same day or separate visit, depending on the timing of the PET imaging, they will be required to attend one half-day session for neuropsychological testing. Patients will arrive at the Toronto Western Hospital, the stimulator will be turned "off" for 30 minutes prior to neuropsychological testing with testing repeated with the stimulator on.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Areas of the brain with low activity	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.	within 30 days of enrollment in the study

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Brain Abnormalities	One Magnetic Resonance Imaging (MRI) scan will be used to take detailed images of the brain and detect whether there are any abnormalities.	within 30 days of enrollment in the study
Ability to learn and understand	One session of neuropsychological testing will be done in order to assess the subject's ability to learn and understand.	within 30 days of enrollment in the study

Collaborators and Investigators

• Sponsor: The Hospital for Sick Children
• Collaborators: University Health Network, Toronto
• Investigators: Principal Investigator: Elysa Widjaja, MD, The Hospital for Sick Children, Toronto Canada

Study record dates

Study Major Dates

• Study Start: March 1, 2010
• Primary Completion (Actual): February 1, 2014
• Study Completion (Actual): February 1, 2014

Study Registration Dates

• First Submitted: June 7, 2010
• First Submitted That Met QC Criteria: June 9, 2010
• First Posted (Estimate): June 10, 2010

Study Record Updates

• Last Update Posted (Estimate): November 21, 2014
• Last Update Submitted That Met QC Criteria: November 20, 2014
• Last Verified: November 1, 2014

More Information

Terms related to this study

• Keywords: Epilepsy; pediatrics; Positron Emission Tomography; Deep Brain Stimulation
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Epilepsy
• Other Study ID Numbers: 1000014496