Article Text

Download PDFPDF
Autoantibodies to glutamic acid decarboxylase in downbeat nystagmus
  1. G Antonini1,
  2. R Nemni2,
  3. F Giubilei1,
  4. F Gragnani1,
  5. V Ceschin1,
  6. S Morino1,
  7. E Bucci1,
  8. N Accornero1
  1. 1Department of Neurological Sciences, University of Rome, “La Sapienza”, Rome, Italy
  2. 2Fondazione Don C Gnocchi, University of Milan, Milan, Italy
  1. Correspondence to:
 Dr G Antonini, Dipartimento di Scienze neurologiche, Viale dell’Università 30, 00185 Rome, Italy;


The cause of downbeat nystagmus (DBN) remains undiagnosed in about 40% of patients. This paper reports the presence of antiglutamic acid decarboxylase antibodies (GAD-Ab) in a patient with DBN. Antibodies against GABAergic neurons located in the vestibular complex may induce chemical denervation of the floccular neurons, which normally suppress the peripheral imbalance between vertical semicircular canal systems, thereby causing DBN. Testing for GAD-Ab may be indicated in DBN patients without an identifiable anatomical brain lesion.

  • downbeat nystagmus
  • anti-GAD antibodies
  • DBN, downbeat nystagmus
  • GAD-Ab, antiglutamic decarboxylase antibodies
  • GABA, γ-aminobutyric acid
  • IDDM, insulin dependent diabetes mellitus

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Competing interests: none declared.