Polymyoclonus, laryngospasm, and cerebellar ataxia associated with adenocarcinoma and multiple neural cation channel autoantibodies

• Main Authors: Lim, S., Mason, W.P., Young, N.P., Chen, R., Bower, J.H., McKeon, A., Pittock, S.J., Lang, A.E.
• Format: Article
• Published: American Medical Association 2009
• Subjects: R Medicine
• Online Access: http://eprints.um.edu.my/1158/; https://jamanetwork.com/journals/jamaneurology/fullarticle/798148
• Institution: Universiti Malaya

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. DESIGN: Case report with video. SETTING: 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.