MUSK and viral encephalitis: These include myasthenia gravis with antibodies against MuSK, encephalitis associated with antibodies against LGI1 or contactin-associated protein-like 2 (CASPR2), and subgroups of patients with Guillain-Barré syndrome or chronic inflammatory demyelinating polyneuropathy (CIDP) with antibodies against neurofascin 155, contactin 1, or CASPR1 [17].