title: Multifocal motor neuropathy: a review of pathogenesis, diagnosis, and treatment.
abstract: Multifocal motor neuropathy (MMN) is an uncommon, purely motor neuropathy associated with asymmetric deficits with predilection for upper limb involvement. Even in the early descriptions of MMN, the associations of anti-GM1 antibodies and robust response to immunomodulatory treatment were recognized. These features highlight the likelihood of an underlying autoimmune etiology of MMN. The clinical presentation of MMN can closely mimic several neurological conditions including those with more malignant prognoses such as motor neuron disease. Therefore early and rapid recognition of MMN is critical. Serological evidence of anti GM-1 antibodies and electrodiagnostic findings of conduction block are helpful diagnostic clues for MMN. Importantly, these diagnostic features are not universally present, and patients lacking these characteristic findings can demonstrate similar robust response to immunodulatory treatment. In the current review, recent research in the areas of diagnosis, pathogenesis, and treatment of MMN and needs for the future are discussed. The characteristic findings of MMN and treatment implications are reviewed and contrasted with other mimicking disorders.
authors.affiliation: Division of Neuromuscular Disorders, Department of Neurology, Wexner Medical Center at The Ohio State University, Columbus, Ohio, USA.
authors.forename: Victoria H
authors.initials: VH
authors.lastname: Lawson
authors.affiliation: Division of Neuromuscular Disorders, Department of Neurology, Wexner Medical Center at The Ohio State University, Columbus, Ohio, USA ; Department of Physical Medicine and Rehabilitation, Wexner Medical Center at The Ohio State University, Columbus, Ohio, USA.
authors.forename: W David
authors.initials: WD
authors.lastname: Arnold
keywords: autoimmune; conduction block; electrodiagnosis; inflammatory; motor neuron; nerve
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