Idiopathic severe recurrent transverse myelitis: a restricted variant of neuromyelitis optica.

Recurrent idiopathic transverse myelitis occur in multiple sclerosis (MS) and neuromyelitis optica (NMO). In NMO, acute optic neuritis and myelitis occur, either monophasic or relapsing, without clinical manifestations of involvement of other parts of the central nervous system (CNS). Recent evidence suggests that NMO is different from multiple sclerosis. The authors reported two patients having severe recurrent transverse myelitis sparing the optic nerves and cerebral hemispheres. Both patients had longitudinally extensive myelitis in some attacks with poor neurological outcome despite aggressive immunomodulatory therapy. One patient had prominent clinical features of brainstem injury with radiological and histological confirmation of brainstem involvement, and the other patient had trigeminal neuralgia suggestive of possible brainstem dysfunction. Histologically, prominent necrosis and neutrophilic infiltration of spinal cord tissue without eosinophils or hyalinized vessels were observed, and oligoclonal bands were absent in their cerebrospinal fluid. It is likely to be a distinct idiopathic inflammatory demyelinating disorder restricted to the spinal cord and brainstem different from MS, but within the spectrum of NMO with probably an autoimmune basis.