title: Volume of the amygdala is reduced in patients with narcolepsy - a structural MRI study.
abstract: OBJECTIVE
  Based on the clinical observation that patients suffering from narcolepsy with cataplexy (NC) have cataplectic attacks when they experience positive emotions, it is therefore hypothesised that the abnormal processing of external emotional input through the limbic system, or motor dysregulation induced by emotions, takes place during these episodes. To date, imaging studies have failed to reveal consistent brain abnormalities in NC patients.
  
  
  METHODS
  Considering the discrepancies in reported structural or functional abnormalities of the hypothalamus, amygdala, and nucleus accumbens, we used the MRI volumetry to determine the volumes of the amygdala and nucleus accumbens in a group of eleven patients with NC (5 males and 6 females, mean age 41.7 years ± 17.7). This data was compared to an equal number of examinations in healthy volunteers matched for age and gender.
  
  
  RESULTS
  We found a decrease in the amygdalar volume of NC patients in both raw (p<0.001) and relative (p<0.01) data sets. The difference in amygdalar volume between healthy volunteers and NC patients was about 17%. In contrast to the amygdala, we did not find any differences in the volumes of nucleus accumbens.
  
  
  CONCLUSIONS
  In the present MRI volumetric study, we found bilateral gray matter loss in the amygdala only.
authors.affiliation: Institute of Anatomy, Charles University, Prague, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Brabec
authors.forename: Aaron
authors.initials: A
authors.lastname: Rulseh
authors.forename: Daniel
authors.initials: D
authors.lastname: Horinek
authors.forename: Andrej
authors.initials: A
authors.lastname: Pala
authors.forename: Helena
authors.initials: H
authors.lastname: Guerreiro
authors.forename: Jitka
authors.initials: J
authors.lastname: Buskova
authors.forename: Pavel
authors.initials: P
authors.lastname: Petrovicky
authors.forename: Veronika
authors.initials: V
authors.lastname: Nemcova
authors.forename: Jan
authors.initials: J
authors.lastname: Krasensky
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Seidl
authors.forename: Christopher
authors.initials: C
authors.lastname: Nimsky
authors.forename: Karel
authors.initials: K
authors.lastname: Sonka
mesh_terms: D000328:Adult; D000679:Amygdala / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000473:pathology*; D009714:Nucleus Accumbens / Q000033:anatomy & histology; D015203:Reproducibility of Results; D055815:Young Adult