A 45-year-old woman comes to the office due to progressive weakness for the past several months. The patient has had difficulty lifting her foster children and getting in and out of her car. She also reports difficulty swallowing and has had several episodes of choking while drinking water. She has no medical problems, but there is a history of breast cancer in her mother. The patient does not use tobacco, alcohol, or illicit drugs. Vital signs are within normal limits, and she has normal sensation and deep tendon reflexes. Strength is 4/5 in the deltoid and quadriceps muscle groups, and there is no limitation in range of motion. Physical examination is otherwise unremarkable. Erythrocyte sedimentation rate is 50 mm/hr, and serum creatine kinase is elevated. TSH is normal. Which of the following is the best initial treatment for this patient?

Question

A 45-year-old woman comes to the office due to progressive weakness for the past several months.  The patient has had difficulty lifting her foster children and getting in and out of her car.  She also reports difficulty swallowing and has had several episodes of choking while drinking water.  She has no medical problems, but there is a history of breast cancer in her mother.  The patient does not use tobacco, alcohol, or illicit drugs.  Vital signs are within normal limits, and she has normal sensation and deep tendon reflexes.  Strength is 4/5 in the deltoid and quadriceps muscle groups, and there is no limitation in range of motion.  Physical examination is otherwise unremarkable.  Erythrocyte sedimentation rate is 50 mm/hr, and serum creatine kinase is elevated.  TSH is normal.  Which of the following is the best initial treatment for this patient?

Quizplus · Accepted Answer

11ec25c8_d515_69e6_bc81_e5e6cf03fbbb_MD0003_00 This patient has features of polymyositis, including chronic proximal muscle weakness, otherwise normal neurologic findings, and an elevated creatine kinase. Peak incidence occurs at age 40-50, and women are more commonly affected than men. Proximal muscle weakness typically manifests as difficulty climbing stairs, getting into or out of a low chair or car, or working with the arms overhead (eg, combing hair). Involvement of upper esophageal musculature can cause dysphagia with regurgitation and aspiration. Inflammatory markers (eg, erythrocyte sedimentation rate) may be elevated, and most patients have detectable autoantibodies (eg, antinuclear antibody, anti-Jo-1). Definitive diagnosis is established on muscle biopsy. Polymyositis resembles dermatomyositis but without associated skin manifestations. Initial remission can be induced with glucocorticoids (eg, prednisone), and most patients also receive a glucocorticoid-sparing agent (eg, methotrexate, azathioprine) to minimize the long-term adverse effects of treatment. Because polymyositis frequently occurs as a paraneoplastic syndrome, patients should also receive age-appropriate cancer screening. (Choices A) Amitriptyline is a tricyclic antidepressant used in a number of chronic pain disorders (eg, fibromyalgia). Fibromyalgia can cause fatigue and reluctance to exercise, but true muscle weakness is absent. (Choices B, E, and G) Beta interferon is sometimes used in the treatment of multiple sclerosis, which initially presents at age 15-50 with episodic neurologic deficits in different distributions (episodes are disseminated in space and time). Pyridostigmine is a cholinesterase inhibitor used to treat myasthenia gravis, which is characterized by weakness that worsens with activity and involves facial and distal limb muscles in addition to proximal muscles. Riluzole is used for amyotrophic lateral sclerosis, a progressive neurodegenerative disorder that causes asymmetric upper (spastic weakness, hyperreflexia) and lower (muscle atrophy, fasciculations) motor neuron features. Muscle enzymes (eg, creatine kinase) are generally normal in these conditions. (Choice C) Cyclobenzaprine is indicated for short-term treatment of muscle spasm associated with acute musculoskeletal conditions (eg, lumbar strain). It is not helpful for muscle weakness. (Choice F) Expedited radiation therapy is necessary for metastatic spinal cord compression. Early signs of cord compression include progressive back pain, symmetric lower extremity weakness, and diminished deep tendon reflexes. Educational objective: Polymyositis is characterized by proximal muscle weakness and elevated creatine kinase. Initial treatment includes systemic glucocorticoids (eg, prednisone), and most patients also receive a glucocorticoid-sparing agent (eg, methotrexate, azathioprine) to minimize the adverse effects of treatment. References: An overview of polymyositis and dermatomyositis. (http://www.ncbi.nlm.nih.gov/pubmed/25641317)

A 45-Year-Old Woman Comes to the Office Due to Progressive