UWorld Internal Medicine Practice Test

The presentation of progressive muscle weakness, obesity, and upper limb weakness leading to difficulty in combing hair is consistent with Cushing syndrome. This condition is characterized by elevated levels of cortisol, which can result from either adrenal tumors, pituitary adenomas (Cushing's disease), or ectopic ACTH production.

In Cushing syndrome, muscle weakness is often more pronounced in proximal muscle groups, making activities such as combing hair and climbing stairs particularly difficult. Additionally, patients frequently exhibit signs of central obesity due to dysregulation of fat distribution, which aligns with the description of the obesity seen in the patient. The combination of these symptoms points to the possibility of hypercortisolism affecting both muscle strength and body composition.

While other conditions may present with certain overlapping symptoms (e.g., hypothyroidism can cause weakness and weight gain, and polycystic ovary syndrome may cause weight changes), they do not typically encompass the syndrome characterized by the specific combination of symptoms outlined in this patient’s presentation. Lambert-Eaton myasthenic syndrome typically presents with proximal muscle weakness as well but is primarily associated with paraneoplastic syndromes and does not typically include significant weight gain or obesity as a prominent feature. Thus, the correct answer is