Myelin oligodendrocyte glycoprotein (MOG) antibody-associated longitudinally extensive transverse myelitis (LETM) and primary Sjogren syndrome: a rare association.

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a recent addition to the field of central nervous system inflammatory disorders. It can have a wide range of presentations, including optic neuritis, transverse myelitis, acute disseminated encephalomyelitis or any combination of these. The aquaporin-4-positive neuromyelitis optica (NMO) is a close differential owing to the similar clinical presentation. There is a proven association between NMO and autoimmunity, whereas such an association is yet to be established in the case of MOGAD. Here we describe the case of a woman in her 30s presenting with sudden-onset quadriparesis with sensory and autonomic involvement who was diagnosed with MOGAD (cervicothoracic longitudinally extensive transverse myelitis) and found to have primary Sjogren syndrome on further workup. This association between MOGAD and autoimmunity should be kept in mind, as diagnosis of the former should alert the physician to the possibility of the latter's existence and the need to initiate an appropriate workup.