Cerebellar ataxia with anti-glutamic acid decarboxylase antibodies: study of 14 patients

Arch Neurol. 2001 Feb;58(2):225-30. doi: 10.1001/archneur.58.2.225.


Background: Antibodies to glutamic acid decarboxylase (GAD-Ab) are described in patients with insulin-dependent (type 1) diabetes mellitus (IDDM), in stiff-man syndrome, and, recently, in a few patients with cerebellar ataxia.

Objectives: To show a link between GAD-Ab and some patients with cerebellar ataxia and to clarify their clinical and immunologic profiles.

Methods: Serum samples were selected from 9000 samples of 4 laboratories. The selection criterion was an immunohistochemical pattern compatible with GAD-Ab that was confirmed by radioimmunoassay. We identified 22 patients with stiff-man syndrome and 14 with cerebellar ataxia and GAD-Ab.

Results: Thirteen of the 14 patients with cerebellar ataxia and GAD-Ab were women, and 11 had late-onset IDDM. Patients did not have clinical or radiologic evidence of brainstem involvement. Ten patients had oligoclonal IgG bands in the cerebrospinal fluid, and intrathecal GAD-Ab synthesis was observed in 5 of the 6 patients studied. The level of GAD-Ab of these patients was similar to those with stiff-man syndrome and significantly higher than those with IDDM or with polyendocrine autoimmunity (P<.001). However, the GAD-Ab levels of 6 of the 9 patients with polyendocrine autoimmunity overlapped with those of patients with cerebellar ataxia.

Conclusions: These results suggest a link between high level of GAD-Ab and some cases of cerebellar ataxia, particularly women with IDDM. If high serum levels of GAD-Ab are detected, the cerebrospinal fluid should be evaluated for the presence of oligoclonal IgG bands and intrathecal synthesis of GAD-Ab to further prove an autoimmune origin of the syndrome.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age of Onset
  • Aged
  • Antibodies, Anti-Idiotypic / blood*
  • Atrophy
  • Cerebellar Ataxia / blood
  • Cerebellar Ataxia / cerebrospinal fluid
  • Cerebellar Ataxia / immunology*
  • Cerebellum / pathology
  • Diabetes Mellitus, Type 1 / blood
  • Diabetes Mellitus, Type 1 / immunology*
  • Female
  • Glutamate Decarboxylase / blood
  • Glutamate Decarboxylase / cerebrospinal fluid
  • Glutamate Decarboxylase / immunology*
  • Humans
  • Immunoglobulins / blood*
  • Immunoglobulins / cerebrospinal fluid
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Oligoclonal Bands
  • Stiff-Person Syndrome / blood*


  • Antibodies, Anti-Idiotypic
  • Immunoglobulins
  • Oligoclonal Bands
  • Glutamate Decarboxylase