Neuromyelitis optica: two new cases and review of the literature.

The clinical features of two recent cases of neuromyelitis optica are reviewed, along with 43 cases from the literature. Severe bilateral visual impairment, thoracic myelitis, prodromal symptoms suggesting a viral syndrome, and moderate pleocytosis of the cerebrospinal fluid (CSF) were characteristic. Respiratory failure developed in 22% of the cases. Seventy percent of patients improved neurologically, 14% had a poor neurological outcome, and 16% died in the acute stages. Predictors of a poor outcome were older age, marked CSF pleocytosis, and severe myelitis. Forty-two percent of patients had a recurrence of demyelinating disease after initial recovery, suggesting a diagnosis of multiple sclerosis. Fifty-eight percent of patients had a self-limited monophasic illness, consistent with a post-infectious encephalomyelitis. No clear predictors of patients at risk for recurrence were identified. CSF oligoclonal bands were absent in three patients with information available.