An 82-year-old woman was admitted for acute gait disturbance and hypoesthesia over 3 days. A general physical examination was normal. Neurological examination revealed muscle weakness of grade 4/5 affecting the right lower limb and grade 1/5 affecting the left lower limb. Deep tendon reflexes were hyperactive in both limbs. Babinski and Chaddock signs were positive on both sides. There was a loss of position and vibration sense combined with hypesthesia below Th10. She had bladder and rectal disturbance. Her Expanded Disability Status Scale (EDSS) score was 8.0. Findings from routine serum studies were normal. Cerebrospinal fluid (CSF) analysis showed a cell count of 2/mL (100% mononuclear cells), normal glucose level, an increased protein concentration of 48 mg/dL, a myelin basic protein (MBP) level of 862 mg/dL (normal range <102 mg/dL), immunoglobulin G (IgG) and albumin ratios of 1.18 (normal range <0.7), and positive oligoclonal bands. Spinal magnetic resonance imaging (MRI) on a T2-weighted image (T2WI) demonstrated two high signals extending from Th1 to Th2 and Th7 to Th9 in the central part of the cord (Fig. , arrows). The lesions showed no contrast enhancement. Brain MRI showed no abnormality. As autoimmune myelitis was suspected, she received high-dose methylprednisolone (1,000 mg/day for 3 days, 3 courses). Her serum was positive for anti-AQP4 antibody (cell-based assay) 17 days after the onset. She was diagnosed with NMOSD and treated with immunoadsorption plasmapheresis and followed up with daily prednisolone (30 mg). Her condition improved and she was able to walk using a walking instrument. Repeat MRI showed marked regression of thoracic lesions 47 days after the onset. She was discharged to another hospital for rehabilitation 50 days after the onset with daily prednisolone (15 mg). Her EDSS score was 5.5.
An 80-year-old man was admitted for subacute gait disturbance. His bilateral lower limb impairment had developed over 2 weeks. A general physical examination was normal. Neurological examination revealed muscle weakness of grade 4/5 affecting both lower limbs. Deep tendon reflexes were absent in both limbs without pathological reflexes. There was loss of deep sensation below T10. He had bladder and rectal disturbance. His EDSS score was 8.5. Findings from routine serum and CSF studies were normal. Spinal MRI on T2WI revealed high signals extending from Th9 to Th12 in the central part of the cord (Fig. ). The lesions showed no contrast enhancement. Brain MRI showed no abnormality. As autoimmune myelitis was suspected, he received high-dose methylprednisolone (1,000 mg/day for 3 days, 2 courses). His serum was positive for anti-AQP4 antibody on the 15th day of his hospitalization. He was diagnosed with NMOSD and treated with immunoadsorption plasmapheresis and followed up with daily prednisolone (30 mg). The muscle strength of the lower limb slightly improved; however, he was bedridden, and the paraplegia persisted. Repeat MRI showed marked regression of thoracic lesions on the 43rd day of his hospitalization. He was discharged to another hospital for rehabilitation 50 days after his hospitalization with daily prednisolone (10 mg). His EDSS score was 7.5.