Abnormal asymmetry in language association cortex in autism.
Autism is a neurodevelopmental disorder affecting cognitive, language, and social functioning. Although language and social communication abnormalities are characteristic, prior structural imaging studies have not examined language-related cortex in autistic and control subjects. Subjects included 16 boys with autism (aged 7-11 years), with nonverbal IQ greater than 80, and 15 age- and handedness-matched controls. Magnetic resonance brain images were segmented into gray and white matter; cerebral cortex was parcellated into 48 gyral-based divisions per hemisphere. Asymmetry was assessed a priori in language-related inferior lateral frontal and posterior superior temporal regions and assessed post hoc in all regions to determine specificity of asymmetry abnormalities. Boys with autism had significant asymmetry reversal in frontal language-related cortex: 27% larger on the right in autism and 17% larger on the left in controls. Only one additional region had significant asymmetry differences on post hoc analysis: posterior temporal fusiform gyrus (more left-sided in autism), whereas adjacent fusiform gyrus and temporooccipital inferior temporal gyrus both approached significance (more right-sided in autism). These inferior temporal regions are involved in visual face processing. In boys with autism, language and social/face processing-related regions displayed abnormal asymmetry. These structural abnormalities may relate to language and social disturbances observed in autism.
Herbert
Martha R
MR
Center for Morphometric Analysis, Massachusetts General Hospital, CNY-149, Room 6012, Boston, MA 02114, USA. mherbert1@partners.org
Harris
Gordon J
GJ
Adrien
Kristen T
KT
Ziegler
David A
DA
Makris
Nikos
N
Kennedy
Dave N
DN
Lange
Nicholas T
NT
Chabris
Chris F
CF
Bakardjiev
Anna
A
Hodgson
James
J
Takeoka
Masanori
M
Tager-Flusberg
Helen
H
Caviness
Verne S
VS
D001321:Autistic Disorder / Q000175:diagnosis* / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology* / Q000503:physiopathology*; D002648:Child; D005625:Frontal Lobe / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007802:Language; D008297:Male; D012016:Reference Values