title: Polymyoclonus, laryngospasm, and cerebellar ataxia associated with adenocarcinoma and multiple neural cation channel autoantibodies.
abstract: OBJECTIVE
  To describe and provide audiovisual documentation of a syndrome of polymyoclonus, laryngospasm, and cerebellar ataxia associated with adenocarcinoma and multiple neural cation channel autoantibodies.
  
  
  METHODS
  Case report with video.
  
  
  METHODS
  University hospitals. Patient A 69-year-old woman presented with subacute onset of whole-body tremulousness and laryngospasm attributed to gastroesophageal reflux.
  
  
  RESULTS
  Further evaluation revealed polymyoclonus, cerebellar ataxia, and laryngospasm suspicious of an underlying malignant neoplasm. Surface electromyography of multiple limb muscles confirmed the presence of polymyoclonus. The patient was seropositive for P/Q-type voltage-gated calcium channel antibody; subsequently, whole-body fluorine 18 fluorodeoxyglucose positron emission tomography and cervical lymph node biopsy revealed widespread metastatic adenocarcinoma. Follow-up serologic evaluation revealed calcium channel antibodies (P/Q type and N type) and potassium channel antibody.
  
  
  CONCLUSIONS
  We highlight the importance of recognizing polymyoclonus. To our knowledge, this is also the first description of a syndrome of polymyoclonus, laryngospasm, and ataxia associated with adenocarcinoma and these cation channel antibodies.
authors.affiliation: University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Shen-Yang
authors.initials: SY
authors.lastname: Lim
authors.forename: Warren P
authors.initials: WP
authors.lastname: Mason
authors.forename: Nathan P
authors.initials: NP
authors.lastname: Young
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.forename: James H
authors.initials: JH
authors.lastname: Bower
authors.forename: Andrew
authors.initials: A
authors.lastname: McKeon
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Pittock
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
mesh_terms: D000230:Adenocarcinoma / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D000368:Aged; D001323:Autoantibodies / Q000276:immunology*; D001932:Brain Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology; D020865:Calcium Channels, P-Type / Q000276:immunology; D020907:Calcium Channels, Q-Type / Q000276:immunology; D002524:Cerebellar Ataxia / Q000150:complications*; D004576:Electromyography; D005121:Extremities / Q000294:innervation / Q000502:physiology; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications; D006801:Humans; D007116:Immunization, Passive; D007473:Ion Channels / Q000276:immunology*; D007826:Laryngismus / Q000150:complications*; D018482:Muscle, Skeletal / Q000502:physiology; D009207:Myoclonus / Q000150:complications*; D049268:Positron-Emission Tomography; D015221:Potassium Channels / Q000276:immunology; D014057:Tomography, X-Ray Computed
chemical_list: D001323:Autoantibodies; D020865:Calcium Channels, P-Type; D020907:Calcium Channels, Q-Type; D007473:Ion Channels; D015221:Potassium Channels