Semin Neurol 2012; 32(05): 544-549
DOI: 10.1055/s-0033-1334477
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Stiff Person Syndrome and Other Anti-GAD–Associated Neurologic Disorders

Praveen Dayalu
1   Department of Neurology, University of Michigan Health System, Ann Arbor, Michigan
,
James W. Teener
1   Department of Neurology, University of Michigan Health System, Ann Arbor, Michigan
› Author Affiliations
Further Information

Publication History

Publication Date:
15 May 2013 (online)

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Abstract

Antibodies directed against glutamic acid decarboxylase (GAD) are present in many patients with stiff person syndrome and increasingly found in patients with other symptoms indicative of central nervous system (CNS) dysfunction, such as ataxia. The classic clinical features of stiff person syndrome include muscular stiffness with superimposed painful muscular spasms. Gait is often impaired. Other CNS disorders associated with GAD antibodies include progressive encephalomyelitis with rigidity and myoclonus (PERM), limbic encephalitis, and even epilepsy. Glutamic acid decarboxylase is the rate-limiting enzyme in the production of gamma-aminobutyric acid (GABA), the primary inhibitory neurotransmitter. Presumably, antibodies directed against GAD impair GABA production, but the precise pathogenic mechanism of GAD-antibody-related neurologic disorders is uncertain. Many patients respond to treatment with immunomodulating therapy. Symptomatic treatment with agents that enhance GABA activity, such as benzodiazepines and baclofen, is also helpful for many patients.