title: Is ictal dystonia associated with an inhibitory effect on seizure propagation in focal epilepsies?
abstract: OBJECTIVE
  In focal epilepsy, ictal version and ictal dystonia are thought to reflect seizure spread into the frontal eye field and the basal ganglia, respectively. Here we investigated whether the occurrence of dystonia during seizure evolution reflects mechanisms preventing secondary generalization. To this aim, the evolution of seizures in patients with focal epilepsies was compared as to whether concomitant (1) dystonia, (2) dystonia and version, or (3) version occurred.
  
  
  METHODS
  Seizure evolutions of 79 patients characterized by either dystonia (n=29; 232 seizures), dystonia and head version in the same seizure evolution (n=9; 83 seizures) or head version (n=41; 330 seizures), were included in the study.
  
  
  RESULTS
  The rate of secondary generalization was significant lower in seizures with ictal dystonia (8%, 6 of 72 seizures) compared to seizures with ictal dystonia and version (62%, 13 of 21 seizures, p<0.0001) or compared to seizures with version (95%, 82 of 86 seizures, p<0.0001).
  
  
  CONCLUSIONS
  This study shows that seizures with unilateral ictal dystonia are less likely to generalize as compared to seizures associated with version. This effect is likely to reflect the involvement of inhibitory mechanisms related to the basal ganglia, which exert an inhibiting effect on secondary seizure generalization.
authors.affiliation: Epilepsy Center, Department of Neurology, University of Munich, Marchioninistrasse 15, Munich, Germany. berend.feddersen@med.uni-muenchen.de
authors.forename: Berend
authors.initials: B
authors.lastname: Feddersen
authors.forename: Jan
authors.initials: J
authors.lastname: Remi
authors.forename: Margret
authors.initials: M
authors.lastname: Kilian
authors.forename: Laurent
authors.initials: L
authors.lastname: Vercueil
authors.forename: Colin
authors.initials: C
authors.lastname: Deransart
authors.forename: Antoine
authors.initials: A
authors.lastname: Depaulis
authors.forename: Soheyl
authors.initials: S
authors.lastname: Noachtar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001479:Basal Ganglia / Q000502:physiology*; D004421:Dystonia / Q000503:physiopathology*; D004828:Epilepsies, Partial / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009433:Neural Inhibition / Q000502:physiology*; D012640:Seizures / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D055815:Young Adult