title: Inter- and intraobserver agreement of seizure behavior scoring in the amygdala kindled rat.
abstract: BACKGROUND
  The Racine scale is a 5-point seizure behavior scoring paradigm used in the amygdala kindled rat. Though this scale has been applied widely in experimental epilepsy research, studies of reproducibility are rare. The aim of the current study was, therefore, to assess its interobserver variability and intraobserver variability.
  
  
  METHODS
  A video database set was acquired in the course of amygdala kindling of 67 Wistar rats. Six blinded observers received scoring instructions and then viewed a set of 15 random videos (session #1). Next, each observer scored 379 to 1048 additional videos (session #2) and finally scored the same set of 15 videos again (session #3). Scores included the occurrence of seizures (yes or no), the total seizure time (start of stimulus until the absence of seizure behavior), and the highest Racine stage. Interobserver variability and intraobserver variability were assessed in and between sessions #1 and #3 using a 2-way mixed intraclass correlation or Cohen's kappa depending on the variable.
  
  
  RESULTS
  Interobserver agreement in session #1 was 0.664 for seizure occurrence, 0.861 for total seizure time, and 0.797 for the highest Racine stage. In session #3, interobserver agreement on seizure occurrence declined to 0.492, total seizure time declined to 0.625, and agreement for the highest Racine stage was 0.725. Interobserver agreement was scored insufficiently on focal R2 seizures in both sessions (0.287 and 0.182). Intraobserver agreement reached >0.80 agreement for seizure occurrence, highest seizure score, and total seizure time in 3 out of 4 observers. Racine's scale stage 2 seizure scores were only 0.135 in one observer but 0.650, 0.810, and 0.635 in the other observers.
  
  
  CONCLUSIONS
  Overall, interobserver agreement and intraobserver agreement in scoring with Racine's scale were adequate. However, because interobserver agreement declined after a period of individually scoring videos, we suggest periodic repetition of the standardized instruction in the course of evaluating videos in order to ensure reproducible results.
authors.affiliation: Maastricht University Medical Center, Dept. of Neurology, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
authors.forename: L J J
authors.initials: LJ
authors.lastname: Groot
authors.affiliation: Maastricht University Medical Center, Dept. of Neurology, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neurosciences, Maastricht University, PO Box 616 (UNS 50, BOX 38), 6200 MD Maastricht, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Gosens
authors.affiliation: School for Mental Health and Neurosciences, Maastricht University, PO Box 616 (UNS 50, BOX 38), 6200 MD Maastricht, The Netherlands; Maastricht University Medical Center, Dept. of Child Neurology, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
authors.forename: J S H
authors.initials: JS
authors.lastname: Vles
authors.affiliation: School for Mental Health and Neurosciences, Maastricht University, PO Box 616 (UNS 50, BOX 38), 6200 MD Maastricht, The Netherlands; Maastricht University Medical Center, Dept. of Neurosurgery, P. Debyelaan 25, 6202 AZ Maastricht, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Hoogland
authors.affiliation: Maastricht University Medical Center, Dept. of Neurology, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neurosciences, Maastricht University, PO Box 616 (UNS 50, BOX 38), 6200 MD Maastricht, The Netherlands; Academic Centre for Epileptology Kempenhaeghe and Maastricht University Medical Center, PO Box 61, 5590 AB Heeze, The Netherlands; University of Technology Eindhoven, Faculty of Electrical Engineering, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
authors.forename: A P
authors.initials: AP
authors.lastname: Aldenkamp
authors.affiliation: Maastricht University Medical Center, Dept. of Neurology, PO Box 5800, 6202 AZ Maastricht, The Netherlands; School for Mental Health and Neurosciences, Maastricht University, PO Box 616 (UNS 50, BOX 38), 6200 MD Maastricht, The Netherlands; Academic Centre for Epileptology Kempenhaeghe and Maastricht University Medical Center, PO Box 61, 5590 AB Heeze, The Netherlands. Electronic address: r.rouhl@mumc.nl.
authors.forename: R P W
authors.initials: RP
authors.lastname: Rouhl
mesh_terms: D000679:Amygdala; D000818:Animals; D001522:Behavior, Animal; D004829:Epilepsy, Generalized / Q000523:psychology; D005260:Female; D007696:Kindling, Neurologic; D015588:Observer Variation; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012640:Seizures / Q000523:psychology*; D014741:Video Recording
keywords: Kindling; Observer variability; Racine scale