Edrophonium Chloride

An 86-year-old woman was admitted to our hospital with cryptogenic progressive dyspnea and dysphagia following a tracheostomy procedure 4 months prior to presentation. She exhibited fluctuating diplopia, bilateral vocal fold paralysis, normal nerve test results, negative findings for serum anti-acetylcholine receptor and anti-muscle-specific kinase antibodies, and positive findings for anti-LDL-receptor related protein 4 (LRP4). A videofluoroscopic swallowing study (VFSS) with edrophonium revealed an improvement in bulbar paralysis. Consequently, the patient was diagnosed with double-seronegative myasthenia gravis (DSN-MG) and began immunomodulatory therapy. This case emphasizes the diagnostic challenges of bulbar-type DSN-MG and underscores the value of a VFSS with edrophonium for diagnosing this condition.

In recent years, immune checkpoint inhibitors (ICI) have become the standard treatments for various cancers. These drugs are monoclonal antibodies targeting mols. such as cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed death 1 (PD-1), and PD-1 ligand (PD-L1). ICI activate the immune system to eliminate malignancies.Here, we report a case of myositis/myocarditis with multiple myositis-specific-antibodies (MSAs) and myositis-associated-antibodies (MAAs) during use of pembrolizumab, a PD-1 inhibitor, which improved with immunotherapy.The result of ice pack test was neg. in this case. I.v. administration of edrophonium did not improve ptosis (1-A), grip strength and upper/ lower limb muscle strength. As described above, the various tests to detect myasthenic symptoms were neg.When clinicians encounter neuroimmune disorders during ICI treatment, it is sometimes difficult to determine whether they are drugderived reactions or tumor-associated symptoms.If the symptoms are drug-derived, the ICI should be discontinued, however, if the symptoms are tumor-related, the ICI should be continued. Simultaneous-positivemultiple MSAs is suggestive of an ICI-derived autoimmune response and may be a useful insight for clinicians treating myositis during ICI use to select a more appropriate treatment.