A 59-year-old man comes to the office due to progressive weakness for the past several weeks. The patient has had difficulty getting out of bed and climbing stairs in the morning, which improves gradually as he "warms up the muscles" with continued use. He has also had to drink water more frequently due to dry mouth and has had episodic double vision. The patient also reports difficulty achieving erections despite having a good libido. Neurologic examination shows decreased strength of the hip flexors and diminished knee reflexes. Repeat examination after lower extremity isometric exercise shows normalization of the muscle strength and deep tendon reflexes. Which of the following conditions is most closely associated with this patient's current disease process?

Question

A 59-year-old man comes to the office due to progressive weakness for the past several weeks.  The patient has had difficulty getting out of bed and climbing stairs in the morning, which improves gradually as he "warms up the muscles" with continued use.  He has also had to drink water more frequently due to dry mouth and has had episodic double vision.  The patient also reports difficulty achieving erections despite having a good libido.  Neurologic examination shows decreased strength of the hip flexors and diminished knee reflexes.  Repeat examination after lower extremity isometric exercise shows normalization of the muscle strength and deep tendon reflexes.  Which of the following conditions is most closely associated with this patient's current disease process?

Quizplus · Accepted Answer

Eductional Objective: Lambert-Eaton myasthenic syndrome (LEMS) is a neuromuscular disorder characterized by autoantibodies against presynaptic voltage-gated calcium channels.  It causes progressive proximal muscle weakness and decreased deep tendon reflexes that improve with exercise (postexercise facilitation); cranial nerve involvement and autonomic symptoms may also occur.  LEMS is strongly associated with small cell lung cancer.

A 59-Year-Old Man Comes to the Office Due to Progressive