A Case of Treatment Resistance and Complications in a Patient with Stiff Person Syndrome and Cerebellar Ataxia

Tremor Other Hyperkinet Mov (N Y). 2019 Oct 1:9. doi: 10.7916/tohm.v0.677. eCollection 2019.

Abstract

Background: Antibodies against glutamic acid decarboxylase (GAD) are associated with Stiff Person Syndrome (SPS).

Case report: A 50-year-old woman presented with symptoms progressed over 9 years, resulting in a cerebellar ataxia and right upper limb tremor. Investigations revealed elevated serum and CSF anti-GAD antibody titres (98.6 and 53.4 μ/ml, respectively). Treatment included intravenous immunoglobulin and immunomodulation (infliximab and rituximab), improving her stiffness, but with no impact on the ataxia-related symptoms. Subsequent high-dose steroids led to diabetic ketoacidosis and unmasking of an insulin-dependent diabetes mellitus.

Discussion: This case illustrates several key features: (1) the combined clinical picture of SPS and cerebellar ataxia is a rare phenotype associated with anti-GAD antibodies; (2) the cerebellar ataxia described was progressive and poorly responsive to immunomodulatory therapy; and (3) the potential for development of further autoimmune sequelae in response to immunosuppression, namely, the development of insulin-dependent diabetes in response to treatment with high-dose oral steroids.

Keywords: GAD autoantibodies; Stiff Person Syndrome; anti-GAD; autoimmune; cerebellar ataxia; cerebellum; movement disorder; treatment.

Publication types

  • Case Reports

MeSH terms

  • Autoantibodies* / blood
  • Cerebellar Ataxia / blood
  • Cerebellar Ataxia / diagnosis*
  • Cerebellar Ataxia / drug therapy*
  • Female
  • Glutamate Decarboxylase* / blood
  • Humans
  • Immunoglobulins, Intravenous / administration & dosage
  • Middle Aged
  • Stiff-Person Syndrome / blood
  • Stiff-Person Syndrome / diagnosis*
  • Stiff-Person Syndrome / drug therapy*

Substances

  • Autoantibodies
  • Immunoglobulins, Intravenous
  • Glutamate Decarboxylase