title: Comparison of concentrations of γ-aminobutyric acid and glutamate in cerebrospinal fluid of dogs with idiopathic epilepsy with and without seizure-related magnetic resonance imaging hyperintense areas in the limbic system.
abstract: OBJECTIVE
  To investigate differences in CSF concentrations of excitatory and inhibitory neurotransmitters in dogs with and without T2-weighted (T2W) MRI hyperintense areas in the limbic system.
  
  
  METHODS
  Archived CSF samples and stored brain MRI images of 5 healthy research dogs (group 1), 8 dogs with idiopathic epilepsy (IE) with no abnormal MRI findings (group 2), and 4 dogs with IE with hyperintense areas in the limbic system detected by means of T2W MRI (group 3).
  
  
  METHODS
  Archived CSF samples and stored MRI images obtained from all dogs were evaluated. Dogs in groups 2 and 3 were matched on the basis of age and breed. High-performance liquid chromatography was used to evaluate glutamate and γ-aminobutyric acid (GABA) concentrations in CSF samples.
  
  
  RESULTS
  Glutamate concentrations were higher in CSF of both groups of dogs with IE than in healthy dogs. However, glutamate concentrations in CSF were not significantly higher in dogs with IE and with hyperintense areas than in dogs with IE but no abnormal MRI findings. Concentrations of GABA in CSF were higher in group 3 than in group 2 and in group 2 than in group 1.
  
  
  CONCLUSIONS
  No significant difference was evident between glutamate concentrations in CSF of dogs with IE and with and without hyperintense areas detected by means of T2W MRI. However, glutamate concentrations typically were higher in CSF of dogs with IE and MRI hyperintense areas. Future studies with larger sample sizes should be conducted to confirm this finding and to determine the clinical importance of high glutamate concentrations in CSF of dogs with IE.
authors.affiliation: Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA 30602, USA. creevy@uga.edu
authors.forename: Kate E
authors.initials: KE
authors.lastname: Creevy
authors.forename: John F
authors.initials: JF
authors.lastname: Gagnepain
authors.forename: Simon R
authors.initials: SR
authors.lastname: Platt
authors.forename: Gaylen L
authors.initials: GL
authors.lastname: Edwards
authors.forename: Marc
authors.initials: M
authors.lastname: Kent
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000134:cerebrospinal fluid* / Q000473:pathology; D004285:Dogs; D004827:Epilepsy / Q000134:cerebrospinal fluid / Q000662:veterinary*; D005260:Female; D018698:Glutamic Acid / Q000134:cerebrospinal fluid*; D008032:Limbic System / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000662:veterinary*; D008297:Male; D005680:gamma-Aminobutyric Acid / Q000134:cerebrospinal fluid*
chemical_list: D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid