Hippocampus and amygdala volumes in parents of children with autistic disorder.
OBJECTIVE
Structural and functional abnormalities in the medial temporal lobe, particularly the hippocampus and amygdala, have been described in people with autism. The authors hypothesized that parents of children with a diagnosis of autistic disorder would show similar changes in these structures.


METHODS
Magnetic resonance imaging scans were performed in 17 biological parents of children with a diagnosis of DSM-IV autistic disorder. The scans were compared with scans from 15 adults with autistic disorder and 17 age-matched comparison subjects with no personal or familial history of autism. The volumes of the hippocampus, amygdala, and total brain were measured in all participants.


RESULTS
The volume of the left hippocampus was larger in both the parents of children with autistic disorder and the adults with autistic disorder, relative to the comparison subjects. The hippocampus was significantly larger in the adults with autistic disorder than in the parents of children with autistic disorder. The left amygdala was smaller in the adults with autistic disorder, relative to the other two groups. No differences in total brain volume were observed between the three groups.


CONCLUSIONS
The finding of larger hippocampal volume in autism is suggestive of abnormal early neurodevelopmental processes but is partly consistent with only one prior study and contradicts the findings of several others. The finding of larger hippocampal volume for the parental group suggests a potential genetic basis for hippocampal abnormalities in autism.
Rojas
Donald C
DC
Department of Psychiatry, University of Colorado Health Sciences Center, Box C268-68 CPH, 4200 E. 9th Ave., Denver, CO 80262, USA. Don.Rojas@uchsc.edu
Smith
J Allegra
JA
Benkers
Tara L
TL
Camou
Suzanne L
SL
Reite
Martin L
ML
Rogers
Sally J
SJ
D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000033:anatomy & histology*; D001321:Autistic Disorder / Q000175:diagnosis* / Q000235:genetics; D001921:Brain / Q000033:anatomy & histology; D002648:Child; D002675:Child, Preschool; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000033:anatomy & histology*; D006801:Humans; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D010290:Parents; D012737:Sex Factors