The neural circuits in our brains require a layer of insulation in order to transmit signals in a rapid and efficient fashion. This insulation is called White Matter and is comprised of a specific type of brain cell called an oligodendrocytes. Damage to brain white matter occurs following injury and in disorders like Multiple Sclerosis and results in sensory, motor, and cognitive problems. Currently there are no effective medical therapies to promote brain repair and reduce disability following damage to white matter. In this project, we hope to change the situation by encouraging the brain itself to generate new oligodendrocytes and thus new white matter. Our first step is to find measures sensitive to white matter growth.

Inclusion Criteria:

• Experienced a demyelinating event (Only applicable to patient subjects)
• Between the ages of 5 years to 18 years and 11 months of age
• Has either English as his or her native language or has had at least two years of schooling in English

Exclusion Criteria:

• Children with non-demyelinating etiologies of white matter dysfunction (i.e., metabolic disorders, vasculitis, and non-specific MRI abnormalities
• Is younger than 5 years of age
• Is 18 years and 11 of age or older
• Has a prior history of traumatic brain injury, neurological disorder, cerebral palsy, developmental delay, or learning disability
• Requires sedation for brain scanning
• Is claustrophobic, as brain scanning requires children to enter a tunnel in the MRI machine

There will be a total of 80 participants in this study. The study population consists of both patients (demyelinating disease) and non-patient participants (healthy volunteers).