Please confirm topic selection

Are you sure you want to trigger topic in your Anconeus AI algorithm?

Please confirm action

You are done for today with this topic.

Would you like to start learning session with this topic items scheduled for future?

Updated: May 28 2019

Lambert-Eaton Syndrome

  • Snapshot
    • A 61-year-old man presents to his neurologist for weakness. He reports that he has weakness with getting up from a chair or climbing the stairs. He also says that he has been having a lot of dry mouth lately, requiring him to frequently drink water. He smokes 1 pack of cigarettes daily for the past 35 years. Physical examination is notable for proximal upper and lower extremity weakness. There is also recovery of his patellar reflexes with brief and vigorous muscle contraction. Serum studies are notable for autoantibodies against voltage-gated calcium channels.
  • Introduction
    • Definition
      • neuromuscular junction disease characterized by progressive muscle weakness
    • Associated conditions
      • small cell lung cancer
  • Etiology
    • Paraneoplastic or nonparaneoplastic phenomenon
  • Pathogenesis
    • Autoantibodies directed against presynaptic voltage-gated calcium channels
      • leads to decreased release of acetylcholine into the neuromuscular junction
      • reduced acetylcholine dereases muscle contraction and results in subsequent weakness
  • Presentation
    • Symptoms/physical exam
      • proximal muscle weakness
        • initially involving the lower extremities
      • autonomic instability
        • dry mouth (most common)
        • orthostatic hypotension
      • improvement in muscle strength (and recovery of deep tendon reflexes) with vigorous and brief muscle contraction
  • Studies
    • Making the diagnosis
      • this is a clinical diagnosis
    • Electromyography
      • confirms the diagnosis
      • findings
        • improved post-exercise increase in compound muscle action potential on repetitive nerve stimulation
    • Serum
      • presence of autoantibodies against voltage-gated calcium channels
        • present in about 85-95% of patients with Lambert-Eaton syndrome
  • Differential
    • Myasthenia gravis
      • differentiating factor
        • fatigable muscle weakness
  • Treatment
    • If Lambert-Eaton syndrome is secondary to small cell lung cancer, then addressing the malignancy will improve symptoms
    • Medical
      • amifampridine
        • indication
          • in patients with function-limiting muscular weakness
  • Prognosis
    • Addressing the underlying cancer will typically improve symptoms
1 of 0
Private Note

Attach Treatment Poll
Treatment poll is required to gain more useful feedback from members.
Please enter Question Text
Please enter at least 2 unique options
Please enter at least 2 unique options
Please enter at least 2 unique options