MG Guidelines Flashcards
What percent of thymoma patient have MG?
30
What percent of MG patients have thymic hyperplasia?
60
What virus infection is correlated with MG?
EBV
What sign? Ptosis is accentuated by passively opening the contralateral eye
Herring sign
What is the Coogan sign?
Repetitive manual elevation of the ptotic eye causes drooping of the opposite lid
What is the quickest way to improve MG strength?
Edrophonium
Mestinon
Neostigmine
Edrophonium immediately
Mestinon 60 to 90 mins
Neostigmine 15 mins
What muscle is used for jitter?
Extensor digitorum communis
What type of achr antibody is most common for MG patients?
BINDING 88%
Which achr ab has the best prognosis? Ocular MG
Blocking
What percentage of patients are negative for AchR antibody?
10-15%
What type of MG is unresponsive to Mesinon?
Anti musk
What abtibody is associated with the ff hla
dr14 and dq5
anti musk
What hla is associated with achr antibodies?
a1 b8 dr3
What is the daily limit of mestinon
900
Re mestinon
Half life
Hours effects last
Bioavailability
Half life 20-30 mins
Hours effects last 4-6 hours
Bioavailability 10%
Which immunologic agent?
Antifolate inhibiting purine and pyrimidine synthesis
Monoclonal antibody against cd20
Inhibits tcell activation and proliferation
Antifolate inhibiting purine and pyrimidine synthesis METHOTREXATE
Monoclonal antibody against cd20 RITUXIMAB
Inhibits tcell activation and proliferation TACROLIMUS
What are the requirements to thymectomy in NON thymomatous MG
Stage 2a or better 18-55 years old Rapid disease progression Duration is within 3-5 years prior to sx High level of antibodies to Ach ab
When does improvement with steroids start? Maximal benefit achieved? Dose to start in hospital setting? Dose to start in OPD?
2-4 weeks
6 months
1mg per kg
10-20mg per day until 100mg per day
What set of patients cannot take AZA for Mg
thiopurine methyltransferase deficiency
What is the MOA of azathioprine?
purine antimetabolite interfering with b and t cell production
What is the starting dose and goal dose of aza?
50mg od
goal 2-3mg per kg per day
Cyclosporine MOA?
blocks calcineurin mediated cytokine signalling thereby inhibiting T cell helper function
What are the adverse effects of cyclosporine? Daily dose?
Htn and renal damage
4-6mg per kg
What immunologic agent blocks the enzyme inosine monophosohate dehydrogenase?
Mycophenolate mofetil
What values indicate crisis?
Vital capacity
Negative inspiratory force
Positive expiratory force
less than 1L
less than 20 h20
less than 40cm h2o
What is the rate of arrythmias in cardiac patients?
11-14%
How long does
Plex
IVIG
Have effect in crisis
Plasma 1-2 days
IVIG 4-5 days
MGFA class?
Moderate weakness of extremities mainly oropharyngeal respiratory
Intubation
Moderate weakness of extremities mainly oropharyngeal respiratory 3b
Intubation 5
OCULAR IS 1
What medication is CONTRAINDICATED IN MG?
D Penicillamine
What drugs MIGHT exacerbate MG?
CLIBS Calcium channel blocker Lithium Iodinated contrast Beta blocker Statins
What percent of MG patients have thymoma?
15