A 65-year-old man noted slowly progressive muscle weakness in his arms and legs over the past 2 years. He considers himself healthy otherwise

A 65-year-old man noted slowly progressive muscle weakness in his arms and legs over the past 2 years. He considers himself healthy otherwise. He has had no pain. He takes simvastatin and hydrochlorothiazide. He is weak both proximally and distally. An electromyogram (EMG) shows both myopathic and neuropathic fi ndings. Laboratory test results include the following: hemoglobin 14.4 g/dL, erythrocyte sedimentation rate 3 mm/h, creatinine 1.0 mg/dL, antinuclear antibodies 1:40 (negative U/L (reference range likely diagnosis? a. Polymyositis b. Amyotrophic lateral sclerosis (ALS) c. Simvastatin toxicity d. McArdle disease e. Inclusion body myositis (IBM)