Patho- NMJ disorders Flashcards
Name two NMJ disorders
Myasthenia Gravis
Lambert-Eaton myasthenic-myopathic syndrome (LEMS)
What is the pathology of myasthenia gravis?
Autoimmune attack of AChR
What are some symptoms of myasthenia gravis?
Muscle weakness and fatigability in proximal muscles, bulbar muscles and ocular muscles
Resp difficulties
No muscle pain
Reflexes disappear on prolonged use
Who tends to get myasthenia gravis?
30s
Women>men
What kind of resp difficulties can myasthenia gravis sufferers develop?
Resp impairment
Nasal regurgitation
Dysphagia
What type of antibody causes myasthenia gravis?
IgG
What diseases can myasthenia gravis be associated with?
Thyroid
RA
Pernicious anaemia
SLE
How can myasthenia gravis be diagnosed?
Clinical- Fluctuating, fatigable weakness
Serum Anti-AChR antibodies
Progressive decreased AP on EMG
How do you treat myasthenia gravis?
Support resp
Oral anticholinesterases- Pyridostigmine
Immunosuppressant drugs- Steroids
Thymectomy
What is the patho of Lambert-Eaton myasthenic-myopathic syndrome (LEMS)
Paraneoplastic manifestation of small-cell bronchial carcinoma
Defective acetylcholine release at the NMJ
What are some symptoms of LEMS?
Proximal limb muscle weakness- Resolves after a few minutes of muscle contraction
Absent reflexes
How do you diagnose LEMS?
EMG
Antibodies to P/Q-type voltage-gated calcium channels
How do you treat LEMS?
Treat underlying cause
Diaminopyridine (DAP)
