A 69-year-old woman developed paraplegia and hypesthesia on upper extremities and below T4 level. Examination of cerebrospinal fluid showed increased protein levels and pleocytosis. MRI of the cervical spinal cord revealed syrinx formation from C3 to upper thoracic cord. A diagnosis of acute transverse myelitis was made. A high dose of corticosteroid including pulse therapy did not improve her symptoms and signs of myelopathy, but the syrinx could not be found thereafter. One year later, she developed severe visual loss due to bilateral optic neuritis which was improved spontaneously. The clinical course and MRI findings were similar to those of the optic-spinal form of multiple sclerosis (MS). The presence of anticardiolipin antibodies, lupus anticoagulant and perinuclear anti-neutrophil cytoplasmic antibodies, however, strongly suggested that vasculitic and/or ischemic mechanisms induced by these autoantibodies might play a role on the development of the disease. We conclude that our case should be distinguished from MS.