Cerebral Palsy and the Study of Brain Activity During Motor Tasks

Background: \- Two ways to study the brain while people are moving are near-infrared spectroscopy (NIRS) and electroencephalography (EEG). NIRS uses light to look at blood flow in the brain when it is active. EEG records electrical activity in the brain. Both have been used safely for many years, even in very young children. NIRS or EEG can be used while a person is moving to show which parts of the brain are the most active. Researchers want to use NIRS and EEG to study brain activity during movement in people with cerebral palsy and healthy volunteers. Learning more about how people with and without cerebral palsy use their brain to control their muscles may lead to new ways of training people with cerebral palsy to move better. Objectives: \- To study how the brain controls body movement in people with and without cerebral palsy. Eligibility: * Individuals at least 5 years of age who have cerebral palsy. * Healthy volunteers at least 5 years of age. Design: * This study has three parts. People with cerebral palsy will be selected for all three. Healthy volunteers will be asked to do only two of them. Everyone who participates will have NIRS and/or EEG exams during movement. People with cerebral palsy may also have biofeedback sessions to train coordination of movement and brain activity. * Participants will be screened with a physical exam and medical history. Urine samples may be collected. * All participants will have at least one session of NIRS and/or EEG imaging studies. Sessions may also include the following tests: * Magnetic resonance imaging to look at the brain * Electromyography to measure electrical activity of the muscles * Motion analysis of specific body parts * Ultrasound to measure activity of the muscles * Motorized, robotic, and electrical stimulation of the muscles * Other clinical tests of muscle movement as needed. * Participants with cerebral palsy will have biofeedback sessions. These sessions will help them learn to coordinate musc