Lambert-Eaton myasthenic syndrome (LEMS) Flashcards
1
Q
What are the 2 main causes of Lambert-Eaton myasthenic syndrome?
A
Paraneoplastic
Autoimmune
2
Q
Which cancer results in LEMS?
A
Small cell lung cancer
3
Q
Describe the pathogenesis of LEMS
A
Antibodies are to Ca2+ channels on pre-synaptic membrane
4
Q
Which antibody is seen in 85-95% of LEMS patients?
A
Anti-P/Q type VGCC antibodies
5
Q
List the clinical features of LEMS
A
Gait difficulty before eye signs
Autonomic involvement - constipation, impotence, dry mouth
Hyporeflexia and weakness which improve greatly after exercise
6
Q
What does EMG show in LEMS
A
Similar to MG but amplitude increases greatly post-exercise
7
Q
How is LEMS treated?
A
Pyridostigmine or IVIg
Regular CXR/high resolution CT as symptoms may precede cancer >4yrs
