Transverse myelitis (TM) is an inflammatory disorder of the spinal cord characterized by acute or subacute inflammation across both sides (transverse) of one or more spinal cord segments, causing motor, sensory, and autonomic dysfunction below the level of the lesion. The inflammation typically targets the thoracic spinal cord (most common site) and produces demyelination and axonal injury. The pathogenesis involves immune-mediated attack on spinal cord myelin or neurons, which may be triggered by viral infections (enteroviruses, HSV, VZV, West Nile virus), post-infectious autoimmune mechanisms (molecular mimicry following respiratory or GI infections), or associated with autoimmune diseases (multiple sclerosis, neuromyelitis optica [NMO], systemic lupus erythematosus, sarcoidosis). NMO-associated TM is mediated by aquaporin-4 (AQP4) antibodies that target astrocyte water channels, causing severe longitudinally extensive TM (≥3 vertebral segments). Clinical presentation typically evolves over hours to days: bilateral (but may be asymmetric) motor weakness progressing to paraplegia, a distinct sensory level below the lesion (loss of all modalities below the affected segment with a band of hypersensitivity at the level), and autonomic dysfunction (urinary retention [most common autonomic finding], bowel dysfunction, sexual dysfunction)....