MRI findings in glutamic acid decarboxylase associated autoimmune epilepsy

Jason R. Fredriksen, Carrie M. Carr, Kelly K. Koeller, Jared T. Verdoorn, Avi Gadoth, Sean J. Pittock, Amy L. Kotsenas

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Purpose: Glutamic acid decarboxylase (GAD65) has been implicated in a number of autoimmune-associated neurologic syndromes, including autoimmune epilepsy. This study categorizes the spectrum of MRI findings in patients with a clinical diagnosis of autoimmune epilepsy and elevated serum GAD65 autoantibodies. Methods: An institutional database search identified patients with elevated serum GAD65 antibodies and a clinical diagnosis of autoimmune epilepsy who had undergone brain MRI. Imaging studies were reviewed by three board-certified neuroradiologists and one neuroradiology fellow. Studies were evaluated for cortical/subcortical and hippocampal signal abnormality, cerebellar and cerebral volume loss, mesial temporal sclerosis, and parenchymal/leptomeningeal enhancement. The electronic medical record was reviewed for relevant clinical information and laboratory markers. Results: A study cohort of 19 patients was identified. The majority of patients were female (84%), with a mean age of onset of 27 years. Serum GAD65 titers ranged from 33 to 4415 nmol/L (normal < 0.02 nmol/L). The most common presentation was medically intractable, complex partial seizures with temporal lobe onset. Parenchymal atrophy was the most common imaging finding (47%), with a subset of patients demonstrating cortical/subcortical parenchymal T2 hyperintensity (37%) or abnormal hippocampal signal (26%). No patients demonstrated abnormal parenchymal/leptomeningeal enhancement. Conclusion: The most common MRI finding in GAD65-associated autoimmune epilepsy is disproportionate parenchymal atrophy for age, often associated with abnormal cortical/subcortical T2 hyperintensities. Hippocampal abnormalities are seen in a minority of patients. This constellation of findings in a patient with medically intractable epilepsy should raise the possibility of GAD65 autoimmunity.

Original languageEnglish (US)
Pages (from-to)239-245
Number of pages7
JournalNeuroradiology
Volume60
Issue number3
DOIs
StatePublished - Mar 1 2018

Keywords

  • Autoimmune encephalopathy
  • Autoimmune epilepsy
  • GAD65
  • Glutamic acid decarboxylase

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine

Fingerprint

Dive into the research topics of 'MRI findings in glutamic acid decarboxylase associated autoimmune epilepsy'. Together they form a unique fingerprint.

Cite this