Hyperreflexia is most likely associated with which condition?

• A. Addison's disease
• B. Ankylosing spondylitis
• C. Graves' disease
• D. Cushing's syndrome

Answer: (D)

Hyperreflexia reflects increased excitability of the motor neurons and is a sign of heightened neuromuscular activity. In the context of endocrine disorders, this brisk reflex response is most classically linked to hyperthyroidism. Elevated thyroid hormone accelerates metabolism and enhances nerve and muscle fiber responsiveness, so deep tendon reflexes become more pronounced. Graves’ disease is a common cause of hyperthyroidism, which is why hyperreflexia is typically associated with Graves’ disease. By contrast, Addison’s disease can lead to fatigue and weaker reflexes, ankylosing spondylitis doesn’t primarily alter reflexes, and Cushing’s syndrome tends to cause proximal muscle weakness with reduced reflexes rather than an increase in reflex speed. Thus, hyperreflexia most strongly points toward a hyperthyroid state, such as Graves’ disease.