PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

• Idiopathic inflammatory demyelinating syndrome, as follows: biopsy-proven if necessary - established diagnosis of multiple sclerosis (MS) using Poser criteria; acute disseminated encephalomyelitis; Marburg's variant of MS Balo's concentric sclerosis
• Eligible without biopsy: acute transverse myelitis; Devic's syndrome
• Acute neurologic deficit markedly affecting consciousness, language, or brainstem/spinal cord function, i.e., aphasia, paraplegia, coma, quadriplegia, hemiplegia, severe organic brain syndrome
• Deficit unresponsive to 5 days of high-dose intravenous methylprednisolone (MePRDL), as follows: deficit duration of 21 days to 3 months AND no improvement 14 days after beginning MePRDL OR deficit duration of 12 to 20 days AND continued deterioration after completion of MePRDL
• No chronically progressive demyelinating disease
• No HIV-associated demyelinating syndrome
• No progressive multifocal leukoencephalopathy
• No optic neuritis

--Prior/Concurrent Therapy--

• No more than 3 months of prior steroid therapy Failure on prior MePRDL required Minimum dose 7 mg/kg per day for 5 days
• At least 6 weeks since other immunosuppressives, e.g., cyclophosphamide, azathioprine, cyclosporine

--Patient Characteristics--

• Renal: Creatinine less than 1.5 mg/dL
• Cardiovascular: No hypovolemia; no infarction; no vasculitis; no other major systemic cardiovascular illness
• Pulmonary: No major respiratory illness
• Other: No infection, including hepatitis or human immunodeficiency virus; no recent intravenous drug abuse; no high-risk sexual behavior; no cardiac, cerebrovascular, or autonomic dysfunction that would increase risk of hypotension; no other major systemic illness that would preclude protocol therapy; no pregnant or nursing women; negative serum pregnancy test required of fertile women; effective contraception required