The brain networks controlling movement are complex, involving multiple areas of the brain. Some neurological disorders, like Parkinson's disease (PD) and essential tremor (ET), cause abnormalities in these brain networks. Deep brain stimulation is a treatment that is used to treat these types of neurological diseases and is thought to help patients by modulating brain networks responsible for movement. Levodopa medication is also used to modulate this brain networks in patients with PD. The overall objective is to develop a unified theory of basal ganglia thalamocortical (BGTC) circuit dynamics that accounts for disease symptomatology, movement, and their inter-relationship. The underlying hypothesis, is that the rigidity and bradykinesia of PD are fundamentally related to excessive functional coupling across nodes in the BGTC motor circuit impeding effective information flow. In this research, the investigator will take advantage of the unique opportunity provided by awake deep brain stimulation surgery to learn more about how the brain functions in a diseased state and how deep brain stimulation changes these networks to make movement more normal. The investigator will simultaneously assess cortical and subcortical electrophysiology in relation to clinical symptoms and behavioral measures and in response to deep brain stimulation, cortical stimulation, and pharmacologic therapy in patients undergoing Deep Brain Stimulation (DBS) implantation surgery.

Call 214-648-5005
studyfinder@utsouthwestern.edu, Sahil.Chilukuri@UTSouthwestern.edu

General anesthesia (GA) is a medically induced state of unresponsiveness and unconsciousness, which millions of people experience every year. Despite its ubiquity, a clear and consistent picture of the brain circuits mediating consciousness and responsiveness has not emerged. Studies to date are limited by lack of direct recordings in human brain during medically induced anesthesia. Our overall hypothesis is that the current model of consciousness, originally proposed to model disorders and recovery of consciousness after brain injury, can be generalized to understand mechanisms of consciousness more broadly. This will be studied through three specific aims. The first is to evaluate the difference in anesthesia sensitivity in patients with and without underlying basal ganglia pathology. Second is to correlate changes in brain circuitry with induction and emergence from anesthesia. The third aim is to evaluate the effects of targeted deep brain stimulation on anesthesia induced loss and recovery of consciousness. This study focuses on experimentally studying these related brain circuits by taking advantage of pathological differences in movement disorder patient populations undergoing deep brain stimulation (DBS) surgery. DBS is a neurosurgical procedure that is used as treatment for movement disorders, such as Parkinson's disease and essential tremor, and provides a mechanism to acquire brain activity recordings in subcortical structures. This study will provide important insight by using human data to shed light on the generalizability of the current model of consciousness. The subject's surgery for DBS will be prolonged by up to 40 minutes in order to record the participant's brain activity and their responses to verbal and auditory stimuli.

Call 214-648-5005
studyfinder@utsouthwestern.edu, Nader.Pouratian@UTSouthwestern.edu