Atopic Myelitis: A New Disease Entity?

Abstract

Atopic myelitis (AM) is one of idiopathic myelitis that has mostly been reported in Far East countries including Korea and Japan. A significant relationship between AM and both hyperIgEaemia and specific antibodies to house dust mice has been found. The AM patients show relatively homogenous clinical manifestations, laboratory findings,and radiological features (1) a preferential involvement of the cervical or thoracic cord, (2) predominant sensory symptoms, (3) low EDSS score, (4) relatively long lesion more than 3 vertebral segments with normal CSF findings including IgG index or oligoclonal band, (5) a negative serum anti-aquaporin 4 antibody, and (6) normal brain MRI. In addition, they have increased eosinophils in peripheral blood. These findings suggest that AM might be a distinctive disease entity not associated with multiple sclerosis or neuromyelitis optica. The exact pathogenetic mechanisms of AM are still unresolved. A recent study reported that IgG antibody specific to Toxocara canis was frequently positive in the serum of AM patients, suggesting the possibility that toxocariasis might be another cause of AM. High-dose steroid pulse therapy and/or plasma exchanges are the mainstay treatment for AM as well as other idiopathic myelitis.