The Impact of Focused Ultrasound Thalamotomy of the Anterior Nucleus for Focal-Onset Epilepsy on Anxiety

The purpose of this study is to evaluate the feasibility, safety, and effects on anxiety of high intensity focused ultrasound ablation (FUSA) in patients suffering from treatment-refractory focal epilepsy and anxiety. FUSA is a non-invasive neurosurgical procedure that uses ultrasound waves, sent directly through the scalp and skull, to precisely target small abnormal areas of the brain. For this study, the targeted area of the brain is the anterior nucleus of the thalamus. This brain region may cause seizures and may also be involved in anxiety. The study will test if FUSA is safe and tolerated, and if it reduces anxiety and brain response to threat in patients with anxiety receiving the procedure for partial-onset epilepsy that is resistant to medications.

This is an open-label, Phase 1 prospective intervention study. Ten (10) adults with refractory, partial-onset epilepsy with moderate-severe anxiety and able to provide informed consent will be enrolled. Patients, eligible for Magnetic Resonance Imaging-guided Focused Ultrasound Ablation (MRgFUSA) of the anterior nucleus of the thalamus (ATN) for treatment-refractory epilepsy and who present moderate-severe anxiety will be enrolled. In addition to the diagnosis of medically refractory epilepsy, patients will need to present moderate to severe anxiety (as measured by the Hamilton Anxiety Rating Scale, HAM-A; HAMA score \> 17) and other protocol specific inclusion and exclusion criteria. Medication-refractory partial or focal-onset epilepsy is often associated with enhanced fear behaviors and clinical anxiety. Exaggerated amygdala reactivity to threat is a cardinal neural phenotype of fear and anxiety disorders. The study will determine if MRgFUSA-ATN is feasible and safe and its effects on anxiety, using neuroimaging and neurological, neurocognitive/neuropsychological, psychiatric assessments before, and 1 day, 1 week, 1 month, 3 months, 6 months and 12 months post MRgFUSA. Feasibility is defined as the ability to create the desired lesion within the anterior nucleus of the thalamus and perform fMRI to measure threat reactivity. Safety will be measured by recording and analyzing any adverse effects that may occur from before surgery through 12 months following the surgery. These will include any new onset of neurological deficits, or performance deterioration on neuropsychological testing. Effects on anxiety will be measured using amygdala reactivity to threat by fMRI and patient- and clinician-reported measures of anxiety symptoms before and after MRgFUSA-ATN up to 12 months.