Diagnosis and therapy of multifocal motor neuropathy (MMN) - consensus statement of the German Centers for Neuromuscular Disease

Multifocal motor neuropathy (MMN) is an acquired immune mediated disease of motor nerves. To date, there are no generally accepted diagnostic criteria. MMN can be diagnosed in the setting of an asymmetric motor neuropathy with neurophysiological evidence of conduction block. The distinction from other motor neuropathies, in particular from lower motor neuron disease (LMN) may be difficult. Criteria favoring MMN are evidence of conduction block and of high-titer IgManti-GM1 antibodies. First line treatment of MMN is with Ivlg. Patients not responding to Ivlg or in whom the disease progresses in spite of Ivlg may be treated with cyclophosphamide. Not recommended (due to lack of effect, inconclusive data, or the risk of deterioration) are corticosteroids, interferone-beta 1a, interferone-alpha, plasmapheresis, immune adsorption and cerebrospinal fluid filtration.