Myasthenia Gravis Flashcards
1
Q
Differential diagnosis of proximal muscle weakness?
A
Botulism Lambert-Eaton syndrome Mitochondrial myopathy Miller-Fisher syndrome Snake bites Polymyositis
2
Q
Lambert-Eaton syndrome
A
Results from presynaptic failure of release of acetylcholine, caused by small cell carcinoma of the lung. There is:
- proximal muscle weakness & pain; power may increase on repeated effort; reflexes are reduced or absent
- ocular & bulbar muscles are spared
3
Q
Investigations in Myasthenia Gravis
A
Acetylcholine receptor antibodies
Anti-striated muscle antibody
Muscle specific kinase antibodies
EMG
Thymoma investigations: CXR, thoracic CT or MRI
Associated conditions - hyperthyroidism & autoimmune disease (TFTs, RA, antinuclear antibodies)
RFTs
4
Q
Drugs that trigger a myasthenic crisis
A
Streptomycin Gentamicin Quinidine Procainamide Beta blockers Opiates Tetracycline
