Investigation of Blood-Brain-Barrier Breakdown Using Manganese Magnetic Resonance Imaging in Drug-Resistant Epilepsy

* INCLUSION CRITERIA: * Age 18-60. * Able to give written informed consent directly. * Drug resistant epilepsy participants will be defined as having clinically documented seizures with consistent EEG evidence as defined by the 1981 International Classification of Epileptic Seizures, refractory to standard anti-seizure treatment for at least one year prior to enrolling in this study and with an average of at least one seizure per month. This criterion will be established by preliminary screening NINDS Epilepsy Service under protocol 18-N-0066. Seizure focus localization will be determined by standard clinical, neurophysiologic, and imaging studies. Prior or concurrent enrollment in 18-N-0066 is required. EXCLUSION CRITERIA: General exclusions: * Patients with epilepsy who are not surgical candidates * Significant structural brain abnormality such as a brain tumor, stroke, brain damage from head trauma or blood vessel abnormalities, on the baseline MRI scan. * Positive test for HIV * Pregnancy or breast-feeding * Claustrophobia to a degree that the subject would feel uncomfortable in the MRI machine. * Cannot lie on their back for at least two hours. * Risk for MRI scan, (e.g., any non-organic implant or other device such as a cardiac pacemaker or infusion pump or other metallic implants, objects or body piercings that cannot be removed, or history of being a welder or metal worker due to small metal fragments in the eye) * Unwilling to allow sharing and/or use in future studies of coded data that are collected for this study MEMRI component specific exclusions (applicable only to patients participating in this arm of the study): * History of post-ictal psychosis or post-ictal aggression * Planning to get pregnant in the next 2 months * History of clinically significant liver or kidney disease that could potentially increase the risk of CNS damage due to manganese exposure * A history of drug or alcohol abuse/dependence (subjects scoring 8 or higher on the AUDIT scale) * Screening lab abnormalities demonstrating values more than 2 times the upper limit of normal for AST, ALT, bilirubin, alkaline phosphatase, BUN, creatinine * Previous presumed occupational exposure to manganese (i.e., having worked in a mine, foundry, smelter, dry cell battery manufacturing facility, or agriculture) * Allergy to manganese * On-going treatment with calcium-channel blocker * Iron-deficiency anemia * Personal history of Parkinson s Disease or Parkinsonism or presence of this disease in a 1st degree relative Gadolinium enhanced MRI component specific exclusions (applicable only to patients participating in this arm of the study): * Estimated GFR \<60, tested within 1 week of scan * Allergy to gadolinium Of note, patients who are ineligible for one arm of the study may still be eligible for and participate in the other arm of the study.