Myotonic Dystrophy systemic involvement includes which combination of organ systems?

• A. It affects only skeletal muscle
• B. It affects only the heart
• C. Cardiac, respiratory, GI, ocular systems
• D. It is confined to limbs

Answer: (C)

Myotonic Dystrophy affects more than just skeletal muscles; it commonly involves several other organ systems as well. Beyond the muscles you see weakness and delayed relaxation (myotonia), the disease often touches the heart, the lungs, the digestive tract, and the eyes. Cardiac involvement can include conduction defects and arrhythmias, so heart rhythm problems are a real concern. Respiratory muscles, including the diaphragm and chest wall, can weaken, leading to breathing difficulties and sleep-related breathing issues. The GI system can be affected by impaired motility and swallowing difficulties, causing dysphagia and other GI symptoms. Ocular involvement frequently includes cataracts and other eye changes. Because these systems can all be affected, the combination of cardiac, respiratory, GI, and ocular involvement best reflects the systemic nature of the disease.