07-13-2006, 01:50 AM
A 72-year-old man comes to the physician because of a 7-month history of leg weakness and dry eyes and mouth. He also has had a 10.4-kg (23-lb) weight loss over the past 4 months despite no change in appetite. He has smoked one and a half packs of cigarettes daily for 50 years. He drinks 4 oz of alcohol daily. He has peptic ulcer disease and emphysema. Medications include cimetidine, theophylline, and low-dose prednisone. Examination shows mild ptosis. He has a barrel-shaped chest. Breath sounds are distant. There is moderate weakness of the proximal muscles of the lower extremities. Reflexes are absent. He has difficulty rising from a chair. Sensory examination shows no abnormalities. An x-ray film shows a hyperinflated chest and a 3 × 4-cm mass in the right hilum. His Neurologic findings are most likely due to a lesion involving which of the following?
A) Muscle membrane
B) Parasympathetic nervous system
C) Peripheral nerve
D) Presynaptic neuromuscular junction
E) Symopathetic nervous system
A) Muscle membrane
B) Parasympathetic nervous system
C) Peripheral nerve
D) Presynaptic neuromuscular junction
E) Symopathetic nervous system