title: [Favourable outcome after treatment with rituximab in a case of seronegative non-paraneoplastic Lambert-Eaton myasthenic syndrome].
abstract: BACKGROUND
  Lambert-Eaton myasthenic syndrome is a rare and autoimmune presynaptic disorder of the neuromuscular junction, due in 85% of cases to autoantibodies directed against voltage-gated calcium channels. It is a paraneoplastic disorder in 50 to 60% of cases. Diagnosis involves a proximal muscle weakness and areflexia, associated with a significant increment after post-exercise stimulation in electrophysiological study. Symptomatic treatment is based on 3,4-diaminopyridine. No etiological treatment has proven its efficacy in both paraneoplastic and non-paraneoplastic Lambert-Eaton myasthenic syndrome.
  
  
  METHODS
  We report a 41-year-old man who presented with a seronegative non-paraneoplastic Lambert-Eaton myasthenic syndrome in whom conventional immunosuppressive treatments (corticosteroids, azathioprine) failed, and who eventually improved after treatment with rituximab.
  
  
  CONCLUSIONS
  Rituximab was an effective and well-tolerated treatment in this case of seronegative non-paraneoplastic Lambert-Eaton myasthenic syndrome. Its indication should be discussed when conventional immunosuppressive therapy fails in both seropositive and seronegative patients.
authors.affiliation: Centre de référence des maladies neuromusculaires et de la SLA, centre hospitalier universitaire de La Timone, 264 rue Saint-Pierre, Marseille cedex 05, France. emmanuelle.boutin@ap-hm.fr
authors.forename: E
authors.initials: E
authors.lastname: Boutin
authors.forename: C
authors.initials: C
authors.lastname: Rey
authors.forename: M
authors.initials: M
authors.lastname: Romeu
authors.forename: J
authors.initials: J
authors.lastname: Pouget
authors.forename: J
authors.initials: J
authors.lastname: Franques
mesh_terms: D000328:Adult; D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D015624:Lambert-Eaton Myasthenic Syndrome / Q000188:drug therapy*; D008297:Male; D000069283:Rituximab; D016896:Treatment Outcome
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D007166:Immunosuppressive Agents; D000069283:Rituximab
keywords: Lambert-Eaton myasthenic syndrome; Rituximab; Syndrome de Lambert-Eaton