Imaging Characterization of the Biomechanical Coupling of Brain and Skull

Background:Traumatic brain injury (TBI) affects over 1.7 million people in the United States each year. Many cases are mild, but people with a history of TBI may have long-term symptoms; they are also known to be more susceptible to future concussions. Researchers are working to understand how TBI affects tissues in and around the brain over the long term. This natural history study will investigate how a TBI may change the stiffness of the brain and its surrounding connective tissues.Objective:To see how the brain and connective tissues respond to small head movements in people with and without a prior TBI.Eligibility:People aged 21 to 65 years with a history of TBI. People with no history of TBI are also needed.Design:Participants will have 1 clinic visit that will last about 4 hours.Participants will have a physical exam. They answer questions to make sure it is safe for them to have a magnetic resonance imaging (MRI) scan of their brain.They will have an MRI scan in 2 parts.During the first part, participants will lie on a table that slides into a large tube. They will hear loud knocking noises. They may wear earplugs or earmuffs. They will lie still for 15 minutes at a time. They will be in the tube for about up to 75 minutes.The second part is called magnetic resonance elastography (MRE). Participants will lie with their head on a pillow that vibrates gently. This test will take 10 minutes.Participants will answer questions about how they feel 1 or 2 days after the procedure.

INCLUSION CRITERIA:In order to be eligible to participate in this study, an individual must meet all of the following criteria:Stated willingness to comply with all study procedures and availability for the duration of the study.Age 21-65.Deemed medically safe for study participation by the subjects attending physicianWithin the TBI group, subjects must have a history of mild TBI at time of initial presentation, defined as Glasgow Coma Scale score of 13-15, loss of consciousness < 30 minutes, and normal structural imaging on CT. Subjects should be less than 10 years from time of injury.Within the TME group, in addition to the TBI characteristics above, subjects should additionally, have presented for TME at the time of initial presentation, evaluated by postcontrast FLAIR imaging.Ability of subject to understand and the willingness to sign a written informed consent document.EXCLUSION CRITERIA:An individual who meets any of the following criteria will be excluded from participation in this study:Within the healthy control group, any history of clinically diagnosed TBI.Other known conditions outside of TBI that may affect brain anatomy.Inner ear problems causing dizziness.Having a height or weight not supported by the MRI scanner.Contraindications to MRI (e.g. pacemaker, pregnancy, claustrophobia).Unwillingness to remove cosmetic metal (e.g. piercings) for the MRI.