154. Evolution of ultrasound abnormalities in multifocal motor neuropathy: Series of five cases

Multifocal motor neuropathy (MMN) is an immune-mediated disorder characterized by slowly progressive asymmetric muscle weakness and electrophysiological findings of motor conduction block. The immunological hypothesis for pathogenesis of MMN is supported by the association, in 30–80% of cases, with high title Anti-GM1 antibodies and positive response to intravenous immunoglobulin (IVIg) therapy. Ultrasound (US) is recently gaining a crucial role in the assessment of immune-related neuropathies. We report the clinical, electrophysiological and US follow-up of five cases of patients affected with MMN treated with IVIg. In two patients (male 44 years old, female 37 years old) who started IVIg treatment soon after onset, US demonstrated complete or partial normalization. Conversely, in the other three patients (two males 49 and 70 years old, female 48 years old) who started IVIg respectively four months, twenty years and 1 year after onset, we observed an incomplete clinical, electrophysiological and ultrasound IVIg response.