Myotonic dystrophy is associated with central sleep apnea, excessive daytime sleepiness, diminished working memory, impaired visuospatial skills, and deficits in problem-solving skills.

Cerebrospinal fluid (CSF) is a clear, colorless fluid that surrounds and protects the brain.

Changes in the composition of CSF can serve as early indicators of changes in brain activity and function. The purpose of this research is to learn about myotonic dystrophy by examining cerebrospinal fluid and brain activity in participants. The tests will be low risk and are well tolerated. The information that we gather from this study may help us evaluate, prevent, diagnose, treat, and improve our understanding of myotonic dystrophy. Funding Source- FDA OOPD

Inclusion Criteria:

• Subjects with DM1 based on genetic testing and/or clinical criteria (some subjects who have positive genetic testing may be asymptomatic, while other subjects who show characteristic clinical features may have declined to have genetic testing done).
• Unaffected subjects are unknown to have myotonic dystropphy or any other muscular dystrophy by history and may have had no genetic testing.
• Clinical indicators of current status, as measured within 30 days of study start: Able to provide informed consent or assent for participation in the study.
• Demographic characteristics (e.g., biologic sex, age): Males and females age 18 years and older.

Exclusion Criteria:

• Medical history of any of the following. State of immunosuppression; pre-existing liver or kidney disease; documented HIV positive; documented hepatitis B and/or C positive.
• Medications and other drugs. Use of anticoagulants within 60 days prior to lumbar puncture and/or blood draw. Use of anti-platelet drugs within 7 days prior to blood draw.
• Contraindications to MRI. The presence of any metal within the body, which would include any medical device containing metal, such as a pacemaker, defibrillator, some heart valves or stents, artificial joint, aneurysm clip, or inner ear device, a history of working with sheet metal, or an injury with metal shrapnel; pregnancy, due to effects of MRI on unborn children.
• Contraindications to Lumbar Puncture. Evidence of increased intracranial pressure or active infection on exam; platelets less than 50,000.
• Other. Inability or unwillingness of the subject to give written informed consent.

1. Individuals with myotonic dystrophy type 1 (DM1), ages 18 and older.
2. Individuals without myotonic dystrophy (unaffected), ages 18 and older.