[Senile-onset recurrent myelitis with anti-aquaporin-4 antibody].

An 81-year-old man presented with sudden-onset paraplegia. Cerebrospinal fluid examination revealed an increased cell count and an elevated protein level; the patient also tested positive for the oligoclonal band (OCB). Gadolinium-enhanced MRI revealed a thoracic cord lesion. On the basis of these results, his condition was diagnosed as acute myelitis. The steroid pulse therapy was ineffective, but intravenous immunogloblin treatment (IVIg) resulted in a slight improvement in the muscle strength of his lower limbs. However, three weeks later, a new thoracic spinal cord lesion developed. He was then diagnosed with multiple sclerosis (MS), and was once again, administered IVIg which proved ineffective then. Furthermore, one and a half month later, his condition relapsed with long lesions extending from the brainstem to cervical cord with respiratory muscles involvement. This time, steroid pulse therapy was effective, and he was able to breathe without, the assistance of a respirator. Anti-aquaporin-4 (AQP4) antibodies were detected in the patient's serum, and hence he was administered oral prednisolone in order to prevent the recurrence of lesions. This was not atypical case of neuromyelitis optica (NMO) because of the patient's advanced age at onset, the presence of OCB, and the absence of optic symptoms. However, the pathogenesis may be similar to that of NMO. In the case of acute myelitis of senile onset, examination for anti-AQP-4 antibodies may be required to administer the appropriate therapy.