title: Lambert-Eaton myasthenic syndrome: Epidemiology and therapeutic response in the national veterans affairs population.
abstract: One nationwide study (The Netherlands) of Lambert-Eaton myasthenic syndrome (LEMS) has been published. We report LEMS epidemiology and its therapeutic response in the United States Veterans Affairs (VA) population.
  
  
  
  Medical records for all active patients (12.5 million) in the VA health system were queried for relevant ICD-9 codes for the period October 1, 1999 to September 30, 2013. Clinical, electrophysiologic, and serologic features were evaluated to confirm diagnosis; epidemiologic and treatment data were collected.
  
  
  
  Point prevalence was estimated at 2.6 per 1,000,000 (confirmed cases) and 3.3 per 1,000,000 (combined confirmed and probable cases). Crude prevalence was similarly estimated at 9.2 and 10.9 per 1,000,000 respectively. A total of 18 of 48 (38%) patients received 3,4-diaminopyridine (3,4-DAP); 14 of 18 (78%) improved.
  
  
  
  This investigation was a large North American epidemiologic study of LEMS. LEMS prevalence in the national VA population was found to be similar to previously published rates in other large international populations. Most patients experienced improvement with therapy, including a majority with 3,4-DAP. Muscle Nerve 56: 421-426, 2017.
authors.affiliation: Department of Neurology, Veterans Affairs Medical Center, Salt Lake City, Utah, USA.|Department of Neurology, University of Utah Health, 729 Arapeen Drive, Salt Lake City, Utah, 84108, USA.
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Abenroth
authors.affiliation: Department of Neurology, University of Utah Health, 729 Arapeen Drive, Salt Lake City, Utah, 84108, USA.
authors.forename: A Gordon
authors.initials: AG
authors.lastname: Smith
authors.affiliation: Department of Neurology, Veterans Affairs Medical Center, Salt Lake City, Utah, USA.|Department of Neurology, University of Utah Health, 729 Arapeen Drive, Salt Lake City, Utah, 84108, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Greenlee
authors.affiliation: Department of Research, Veterans Affairs Medical Center, Salt Lake City, Utah, USA.
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Austin
authors.affiliation: Department of Neurology, Veterans Affairs Medical Center, Salt Lake City, Utah, USA.|Department of Neurology, University of Utah Health, 729 Arapeen Drive, Salt Lake City, Utah, 84108, USA.
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Clardy
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use; D015624:Lambert-Eaton Myasthenic Syndrome / Q000453:epidemiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010956:Plasmapheresis / Q000639:trends; D011159:Population Surveillance / Q000379:methods; D026902:Potassium Channel Blockers / Q000627:therapeutic use; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014493:United States Department of Veterans Affairs / Q000639:trends; D014728:Veterans
chemical_list: D016756:Immunoglobulins, Intravenous; D026902:Potassium Channel Blockers
keywords: 3,4-diaminopyridine; Lambert-Eaton myasthenic syndrome; electrophysiology; epidemiology; voltage-gated calcium channel