The term ‘Devic's syndrome’ has usually been applied in the context of there being severe, more-or-less complete episodes of transverse myelitis, in conjunction with episodes of optic neuritis, the episodes occurring in either a monophasic or multiphasic fashion. A complete transverse myelitis is uncommon in multiple sclerosis. Given this definition of Devic's syndrome, there are a few cases in whom a specific underlying disease association is found.
These include systemic lupus erythematosus, acute disseminated encephalomyelitis (presenting as simultaneous and monophasic transverse myelitis and bilateral optic neuritis), and Behçet's disease. In many instances, however, a specific aetiology is not found. Two recent series of such cases have been reviewed (Mandler et al. 1993, O'Riordan et al. 1996), and a number of features have emerged which point to a rather characteristic syndrome distinct from classical relapsing-remitting multiple sclerosis:
preponderance of non-Caucasians;
relatively high frequency of poor recovery from the relapses, which often result in severe paraparesis and visual loss in the acute stages;
low frequency of CSF oligoclonal bands, but often a marked pleocytosis acutely, sometimes with a neutrophil predominance;
brain MRI is often normal;
spinal cord MRI shows extensive swelling and signal change over multiple segments in the acute stage, an appearance like that seen in post-infectious transverse myelitis but unlike the smaller lesions that more commonly manifest in multiple sclerosis;
high frequency of organ-specific antibodies.
Post-mortem data: extensive changes, including necrosis, have been seen in the spinal cord, with demyelination in the optic nerves but sparing of the brain.
Taken together, the data suggest that in many cases, Devic's neuromyelitis optica can be regarded as a clinicopathological entity distinct from multiple sclerosis.
Treatment of acute disabling episodes will usually consist of a short course of high-dose steroids. If there are repeated episodes of optic nerve and spinal cord relapse, some, but not all, neurologists may use some form of immunosuppression.