Brain Structure and Clinical Endpoints in Myotonic Dystrophy Type 2

DM 2 Inclusion Criteria: * Age 30-65 years old * Diagnosis of DM1 or DM2 is based on genetic testing and/or clinical criteria. If the diagnosis is based on clinical criteria, positive DM2 genetic testing is required in first-degree relatives * Symptoms or clinical findings of proximal muscle weakness * Ambulate independently (a cane or walking stick is permitted) * Able to provide informed consent for participation in the study DM1 Inclusion Criteria: * Only individuals who are 30-65 years old will be eligible to participate for the full study protocol * Diagnosis of adult-onset DM1 is based on genetic testing or clinical criteria. If the diagnosis is based on clinical criteria, positive DM1 genetic testing is required in first-degree relatives * The onset of first symptoms must be between the 2nd and 4th decades of life * Symptoms or clinical findings of distal muscle weakness and myotonia * Ambulate independently (a cane or walking stick is permitted) * Able to provide informed consent for participation in the study DM 1 Exclusion Criteria: * Congenital or juvenile-onset DM1 (onset of first symptom \< 20-year-old) * Individuals with a prior diagnosis of dementia, seizure, stroke, multiple sclerosis, Parkinson's Disease, or other neurodegenerative diseases * Individuals with active psychiatric illness or alcohol/substance abuse. * On medications with substantial sedative or cognitive side effects unless the doses have been stable for at least 3 months before the study visit. * Inability or unwillingness to give written informed consent. DM 1 and 2 and Healthy Control (HC) Exclusion Criteria: * Individuals with a pacemaker, defibrillator, or metal implanted that is contraindicated for MRI * Individuals who are claustrophobic * Individuals with a prior diagnosis of dementia, seizure, stroke, multiple sclerosis, Parkinson's Disease, or other neurodegenerative diseases * Individuals with active psychiatric illness, alcohol or substance abuse, or dependence * Individuals with a pacemaker, defibrillator, or metal implanted that is contraindicated for MRI * Individuals who are claustrophobic * Major medical illness which would prevent safe testing of MRI or motor function. * On medications with substantial sedative or cognitive side effects unless the doses have been stable over the last 3 months before the study visit * pregnancy * Weight \> 400 pounds as the participant could not be properly positioned on the MRI table * Inability or unwillingness to give written informed consent * For participants who undergo lumbar puncture procedure: Use of anti-platelet medications within 7 days, use of anticoagulants such as warfarin (Coumadin), history of a bleeding disorders, evidence of platelet count \< 150,000 within the last 6 months, or have hardware (i.e., pins, screws, rods, etc.) in the lower back area Healthy Control (HC) Inclusion Criteria: * Age 30-65 years * Ambulate independently * Able to provide informed consent for participation in the study