Brain Structure and Clinical Endpoints in Myotonic Dystrophy Type 2

DM 2 Inclusion Criteria:

• Age 40 and older

• Diagnosis of DM1 or DM2 is based on genetic testing and/or clinical criteria. If thediagnosis is based on clinical criteria, positive DM2 genetic testing is required infirst-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:

• Age 20 and older. Only individuals who are 40 years or older will be eligible toparticipate for the full study protocol

• Diagnosis of adult-onset DM1 is based on genetic testing or clinical criteria. Ifthe diagnosis is based on clinical criteria, positive DM1 genetic testing isrequired 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 doseshave 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 iscontraindicated 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, ordependence

• Individuals with a pacemaker, defibrillator, or metal implanted that iscontraindicated 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 doseshave 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 MRItable

• Inability or unwillingness to give written informed consent

• For participants who undergo lumbar puncture procedure: Use of anti-plateletmedications within 7 days, use of anticoagulants such as warfarin (Coumadin),history of a bleeding disorders, evidence of platelet count < 150,000 within thelast 6 months, or have hardware (i.e., pins, screws, rods, etc.) in the lower backarea

Healthy Control (HC) Inclusion Criteria:

• Age 40 and older

• Ambulate independently

• Able to provide informed consent for participation in the study