Clinical Research Directory

Motor Cortex Stimulation for Post-Stroke Thalamic Pain

The goal of this clinical trial is to investigate the mechanisms and predictive factors of motor cortex stimulation (MCS) for treating post-stroke thalamic pain, a challenging central neuropathic pain condition. Approximately 25% of patients show no short-term response to MCS, and about 20% experience long-term efficacy decay, yet the underlying analgesic mechanisms remain unclear and objective predictive biomarkers are lacking. This study aims to answer the following main questions: How does MCS modulate thalamic pain through the coordinated interaction of structural connectivity, functional network dynamics, and metabolic balance in the brain? What are the distinct neuroimaging characteristics that differentiate short-term non-responders, long-term responders, and those with long-term efficacy decay? Which multimodal imaging biomarkers can reliably predict short-term and long-term MCS efficacy? Participants will undergo a two-stage MCS surgical procedure. In stage I, epidural electrodes are implanted over the motor cortex, followed by a 2-week external trial stimulation. Participants who achieve a ≥50% reduction in Visual Analog Scale (VAS) pain score will proceed to stage II, receiving an implanted pulse generator for long-term stimulation. Those who do not respond in the short term will have the electrodes removed without undergoing stage II implantation. All participants will complete baseline clinical assessments and multimodal MRI scans (including T1, DTI, resting-state fMRI, and MRS) before surgery. Participants who receive the permanent implant will undergo follow-up clinical evaluations and repeat MRI scans at 3 and 6 months post-surgery. Researchers will compare imaging features across three outcome groups-short-term non-responders, long-term responders, and long-term decay group-to identify predictive biomarkers. Multimodal imaging data will be integrated using LASSO regression to build prediction models for both short-term screening and long-term efficacy warning. This research is expected to establish a "mechanism exploration - efficacy prediction - clinical decision" paradigm, providing objective imaging-based evidence to guide patient selection and postoperative management for MCS treatment.

Effects of Brain Stimulation on Food Intake and Behavioral Weight Loss Treatment

This study will determine whether electrical stimulation of an area of the brain called the dorsolateral prefrontal cortex, which is important in determining the feeling of fullness after eating, affects how much food a person eats and weight loss over 4 weeks. It will also compare weight changes in people who attend weight loss counseling sessions and those who do not over this period of time. Obese, non-diabetic people between 18 and 60 years of age who are in good health and who live in the Phoenix, AZ, metropolitan area are eligible for this study. Candidates must have a body mass index of 35 kg/m(2) or more and weigh less than 350 pounds. Participants are admitted to the NIH inpatient unit in Phoenix for the first 9 days of the study for tests, which include meal tests to determine eating behaviors and caloric intake, blood and urine tests, glucose tolerance test, weight measurement, psychological assessments and DEXA scan to measure body fat. For 3 of the days, they will be asked to eat all of their food from automated vending machines. Some subjects receive transcranial direct current stimulation (TDCS). For this procedure, electrodes that conduct electricity are placed on the head and arm and the current is turned on for 40 minutes. Some tingling may be felt under the electrodes. Other subjects receive sham TDCS, with the current turned on only very briefly. After the evaluations, subjects are discharged home from the NIH unit and instructed to eat 25 percent fewer calories than they consumed while on a weight maintenance diet the first 3 days of their inpatient stay. They maintain the lower calorie diet at home for 4 weeks. During this period they come to the NIH unit 3 days a week to receive either real or sham TDCS.

Evaluating Safety and Feasibility of Transcutaneous Spinal Cord Stimulation Following Traumatic and Non-Traumatic Spinal Cord Injury: A Pilot Study

The study will be a non-randomized, non-blinded pilot study to analyze the safety and feasibility of a non-significant risk device, transcutaneous spinal cord stimulation. The aim is to include 30 total patients, 10 patients in each of 3 groups: 1. Non-traumatic spinal cord injury (ntSCI) with diagnosis of degenerative cervical myelopathy and offered surgical intervention. 2. Early tSCI screened during the hospital admission when cervical/thoracic spinal injury was diagnosed. 3. Delayed tSCI (control) screened 6-24 months after acute cervical/thoracic spinal injury.