02-11-2008, 02:02 PM
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 x 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
) Sympathetic nervous system
A
) Muscle membrane
B
) Parasympathetic nervous system
C
) Peripheral nerve
D
) Presynaptic neuromuscular junction
E
) Sympathetic nervous system