title: Magnetic resonance features of the feline hippocampus in epileptic and non-epileptic cats: a blinded, retrospective, multi-observer study.
abstract: BACKGROUND
  Hippocampal necrosis in cats has been reported to be associated with epileptic seizures. Magnetic resonance imaging (MRI) features of temporal lobe (TL) abnormalities in epileptic cats have been described but MR images from epileptic and non-epileptic individuals have not yet been systematically compared. TL abnormalities are highly variable in shape, size and signal, and therefore may lead to varying evaluations by different specialists. The aim of this study was to investigate whether there were differences in the appearance of the TL between epileptic and non-epileptic cats, and whether there were any relationships between TL abnormalities and seizure semiologies or other clinical findings. We also investigated interobserver agreement among three specialists.
  
  
  METHODS
  The MR images of 46 cats were reviewed independently by three observers, who were blinded to patient data, examination findings and the review of the other observers. Images were evaluated using a multiparametric scoring system developed for this study. Mann-Whitney U-tests and chi-square were used to analyse the differences between observers' evaluations. The kappa coefficient (k) and Fleiss' kappa coefficient were used to quantify interobserver agreement.
  
  
  RESULTS
  The overall interobserver agreement was moderate to good (k =0.405 to 0.615). The MR scores between epileptic and non-epileptic cats did not differ significantly. However, there was a significant difference between the MR scores of epileptic cats with and without orofacial involvement according to all three observers. Likewise, MR scores of cats with cluster seizures were higher than those of cats without clusters.
  
  
  CONCLUSIONS
  Cats presenting with recurrent epileptic seizures with orofacial involvement are more likely to have hippocampal pathologies, which suggests that TL abnormalities are not merely unspecific epileptic findings, but are associated with a certain type of epilepsy. TL signal alterations are more likely to be detected on FLAIR sequences. In contrast to severe changes in the TL which were described similarly among specialists, mild TL abnormalities may be difficult to interpret, thus leading to different assessments among observers.
authors: Small Animal Veterinary Hospital Stommeln, D 50259, Pulheim, Germany. anne-classen@gmx.de.
authors: Anne Christine
authors: AC
authors: Claßen
authors: Clinical Unit of Diagnostic Imaging, University of Veterinary Medicine, A 1210, Vienna, Austria.
authors: Sibylle
authors: S
authors: Kneissl
authors: Division of Clinical Radiology, Vetsuisse Faculty, University of Bern, CH 3012, Bern, Switzerland.
authors: Johann
authors: J
authors: Lang
authors: Department of Biomedical Sciences, University of Veterinary Medicine, A 1210, Vienna, Austria.
authors: Alexander
authors: A
authors: Tichy
authors: Clinic for Internal Medicine, University of Veterinary Medicine, A 1210, Vienna, Austria.
authors: Akos
authors: A
authors: Pakozdy
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002415:Cats; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D006624:Hippocampus / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D012189:Retrospective Studies; D013702:Temporal Lobe / Q000000981:diagnostic imaging
keywords: Cluster seizures; Epileptic seizure; Feline temporal lobe epilepsy; Hippocampal necrosis; Hippocampal sclerosis; Interobserver agreement; Magnetic resonance imaging; Orofacial automatism; Orofacial involvement; Status epilepticus