Based on their presumed immuno-mediated etiology, post-infectious CNS disorders are commonly treated with high-dose
steroids. Factors influencing treatment effectiveness, possible alternative options for
steroid-resistant cases, and their outcome profiles, remain unclear. We here describe the clinical features, the prognosis and the efficacy of i. v.
immunoglobulins (
IVIg) in a series of severe ADEM refractory to
steroids. We performed an inception cohort study on inpatients of the Neurologic and
Infectious Disease Clinics, consecutively admitted over eight years, with a minimum two-year follow-up. Nineteen patients affected by classic and site-restricted ADEM were treated with
IVIg after
steroid failure. Five other patients received
IVIg as first-line treatment due to
steroids contraindications: although not included in the analysis, they were monitored for anecdotal comparison.
Steroids were administered as IV
6-methylprednisolone (6-MP) 500/1000 mg daily until a maximum dose of 6-8 g;
IVIg were administered at 0.4 g/kg/day for 5 days. The outcome was assessed by the Scripps Neurological Rating Scale (SNRS) score with determined periodicity. We observed that
steroid-resistant patients showed high prevalence of PNS damage (89%) and
myelitis (95 %). Other features were old age, severe disability at onset, and moderate to severe blood-brain-barrier (BBB) damage on CSF. In 10/19 patients (53 %)
IVIg were effective, the clinical improvement beginning within the end of the five-day cycle,without relapses. Prominent effects of
IVIg were detectable on motor dysfunction. Milder onset disability (p = 0.013) and lower CSF
albumin (p = 0.006) were the predictors of
IVIg response. Among
steroid-free patients, 3/5 were responsive to
IVIg. We conclude that
IVIg can be useful in a portion of patients with severe
steroid-resistant ADEM and prominent motor dysfunction. Unsolved issues regard the usefulness of
IVIg in less selected groups, and the spectrum of their clinical effects.