Which novel immunomodulatory treatment(s) do you consider in refractory seronegative bulbar-predominant myasthenia?  

Re-evaluate the diagnosis. Acetylcholine receptor and MuSK antibody-negative myasthenia with prominent bulbar symptoms, refractory to all the agents mentioned (steroids, MMF, AZA, IVIG) is an extremely rare scenario. Differential diagnosis includes bulbar onset ALS and numerous myopathies (e.g. IB...