Q. A 63-year-old man presents to the clinic with a 3-month history of progressive muscle weakness, frequent falls, difficulty swallowing, and unexplained weight loss. His family noticed changes in his personality, memory lapses, and occasional confusion. He has been smoking one pack of cigarettes per day for the last 35 years. On physical examination, the patient has muscle wasting with proximal muscle weakness. His reflexes are brisk, and there is noted dysmetria on the finger-to-nose test. The rest of the examination is unremarkable. Laboratory tests reveal a sodium level of 125 mEq/L, potassium of 4.2 mEq/L, creatinine of 0.8 mg/dL, and calcium of 9.1 mg/dL. The patient's complete blood count is normal, and the liver function tests are within the normal range. Anti-Hu antibodies were detected in serum. What would be the most appropriate next step in the management of this patient?