MuSK-myasthenia gravis in a patient with overlap syndrome — Bickerstaff encephalitis and pharyngo-cervico-brachial variant of Guillain-Barré syndrome

This is the fi rst clinical report of a patient with MuSK-myasthenia gravis combined with Bickerstaff ’s brainstem encephalitis and a pharyngo-cervico-brachial variant of Guillain-Barré syndrome. There were observed previously unreported and rare symptoms in Bickerstaff ’s brainstem encephalitis: palinopsia, allesthesia, derealization, and depersonalization states; in the pharyngo-cervico-brachial variant of Guillain-Barré syndrome, there was involvement of peripheral structures of the visual pathway and the peripheral autonomic nervous system. Manifestations of Bickerstaff ’s brainstem encephalitis included pronounced somnolence, pyramidal and cerebellar symptoms, and psychiatric disturbances; a notable feature was its development following a coronavirus infection and a relapsing course. The diagnosis of the pharyngo-cervico-brachial variant of Guillain-Barré syndrome was based on fi ndings such as hyporefl exia, results of electroneuromyography, elevated protein levels in cerebrospinal fl uid, and involvement of peripheral segments of the optic nerve and autonomic nervous system.