ACHE and myasthenia gravis: While SCCMS may mimic myasthenia gravis (MG), it can be distinguished from autoimmune MG by the presence of repetitive compound motor action potential (CMAP) on electrophysiological testing [2], pathogenic variants of relevant genes, poor response to acetylcholinesterase (AChE) inhibitor medications [3], and clinical improvement to channel blocking agents such as fluoxetine and quinidine [3,4].