A 63-Year-Old Man Presents With Slowly Progressive Dyspnea on Exertion and Lower Extremity Muscle Weakness

Area of Science:

• Neurology
• Pulmonology
• Internal Medicine

Background:

• Progressive dyspnea on exertion is a common but complex symptom with diverse etiologies.
• Evaluating the underlying cause requires a thorough history, physical examination, and targeted investigations.
• Neuromuscular disorders can present with respiratory compromise and subtle motor deficits.

Observation:

• A 63-year-old male presented with a 7-year history of gradually worsening dyspnea on exertion.
• Symptoms included orthopnea, difficulty with water immersion, and mild symmetric lower limb weakness during strenuous activity.
• Obstructive sleep apnea (OSA) was present and managed with continuous positive airway pressure (CPAP).

Findings:

• The patient's constellation of symptoms suggests a potential underlying neuromuscular condition affecting respiratory and motor function.
• The progressive nature and specific triggers (exertion, supine position) are key diagnostic clues.
• Exclusion of other common causes like cardiac or pulmonary disease is essential.

Implications:

• This case underscores the importance of considering less common neuromuscular etiologies in patients with unexplained progressive dyspnea.
• Early diagnosis and management of such conditions can potentially improve quality of life and prevent further decline.
• Further investigation is warranted to identify the specific neuromuscular disorder and guide treatment strategies.