title: Clinical spectrum and evolution of monoclonal gammopathy-associated neuropathy: an observational study.
abstract: BACKGROUND
  Paraproteinemic neuropathy (PPN) is often under-diagnosed because of its clinical and electrophysiological variability. Progression of neuropathy is considered an alarm bell for possible malignant conversion of underlying monoclonal gammopathy (MG).
  
  
  OBJECTIVE
  To report clinical presentation, course, and evolution in a group of patients with PPN in order to identify findings useful for achieving the diagnosis, suspecting progression, and recognizing the underlying hematological conditions.
  
  
  METHODS
  Thirty-nine patients with PPN underwent clinical examination, electrodiagnostic studies, cerebrospinal fluid analysis, and laboratory tests. These parameters were compared between the different peak groups.
  
  
  RESULTS
  IgM MG was found in 51.4%, IgG MG in 33.3%, and IgA MG in 10.3% of our cohort. PPN appeared as mainly sensory, demyelinating, mildly progressive neuropathy, regardless of the type of peak or light chain. However, axonal findings were present in many IgG patients and in part of the IgM patients and a small number of the IgG patients may have presented with motor symptoms at the onset. The IgM patients had a significant tendency toward clinical worsening and IgG subjects had a more elevated rate of malignancy. IgA-related neuropathies were rare, heterogenous, and with a high tendency to evolution and malignancy.
  
  
  CONCLUSIONS
  Most of PPN often present a relatively monomorphic clinical picture but they can be clinically heterogenous and must be suspected even if sensory impairment and demyelination are not the dominant features. Tendency to malignancy seems globally elevated and needs intensive follow-up. Diagnostic approach to patients presenting with peripheral neuropathy should always include the typing of monoclonal immunoglobulins in serum and urine. In contrast, patients presenting with MG should be submitted to nerve conduction study/electroneurography and neurological evaluation.
authors.affiliation: Unit of Clinical Neurology, Section for Neuromuscular Diseases and Neuropathies, University Hospital Spedali Civili, Brescia, Italy. filosto@med.unibs.it
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Filosto
authors.forename: Mariasofia
authors.initials: M
authors.lastname: Cotelli
authors.forename: Alice
authors.initials: A
authors.lastname: Todeschini
authors.forename: Laura
authors.initials: L
authors.lastname: Broglio
authors.forename: Valentina
authors.initials: V
authors.lastname: Vielmi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Rinaldi
authors.forename: Valeria
authors.initials: V
authors.lastname: Gregorelli
authors.forename: Marco
authors.initials: M
authors.lastname: Benelle
authors.forename: Alessandro
authors.initials: A
authors.lastname: Padovani
mesh_terms: D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001369:Axons / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D010265:Paraproteinemias / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D010523:Peripheral Nervous System Diseases / Q000453:epidemiology / Q000209:etiology*