Corpus callosum size in adults with high-functioning autism and the relevance of gender.
The goal of the study was to investigate the size of the corpus callosum (CC) and its subsegments in relation to total brain volume (TBV) as an empirical indicator of impaired connectivity in autism with special respect to gender. In MRI data sets of 29 adults with high-functioning autism (HFA) and 29 age-, gender- and IQ-matched control subjects, the TBV was measured and the CC was analyzed as a whole and in subsegments employing two different manual segmentation procedures. With respect to diagnosis, there were no significant differences in the dependent variables (CC, CC subsegments, and TBV). With respect to gender, only TBV was significantly increased in males compared with females, resulting in a significantly decreased CC/TBV ratio in males. This finding, however, was independent from gender and can be fully attributed to brain size. Our findings do not support the following hypotheses: (1) a hypothesis of impaired CC in HFA adults as a subgroup of patients with autism spectrum disorders, and (2) the sexual dimorphism hypothesis of the CC.
Tepest
Ralf
R
Department of Psychiatry and Psychotherapy, University of Cologne, Germany. ralf.tepest@uk-koeln.de
Jacobi
Esther
E
Gawronski
Astrid
A
Krug
Barbara
B
Möller-Hartmann
Walter
W
Lehnhardt
Fritz G
FG
Vogeley
Kai
K
D000328:Adult; D001321:Autistic Disorder / Q000473:pathology*; D016022:Case-Control Studies; D003337:Corpus Callosum / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D055815:Young Adult