Cerebral Metabolic Changes Associated With Thalamic Stimulation

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.

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.

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.