Describing the brain in autism in five dimensions--magnetic resonance imaging-assisted diagnosis of autism spectrum disorder using a multiparameter classification approach.
Autism spectrum disorder (ASD) is a neurodevelopmental condition with multiple causes, comorbid conditions, and a wide range in the type and severity of symptoms expressed by different individuals. This makes the neuroanatomy of autism inherently difficult to describe. Here, we demonstrate how a multiparameter classification approach can be used to characterize the complex and subtle structural pattern of gray matter anatomy implicated in adults with ASD, and to reveal spatially distributed patterns of discriminating regions for a variety of parameters describing brain anatomy. A set of five morphological parameters including volumetric and geometric features at each spatial location on the cortical surface was used to discriminate between people with ASD and controls using a support vector machine (SVM) analytic approach, and to find a spatially distributed pattern of regions with maximal classification weights. On the basis of these patterns, SVM was able to identify individuals with ASD at a sensitivity and specificity of up to 90% and 80%, respectively. However, the ability of individual cortical features to discriminate between groups was highly variable, and the discriminating patterns of regions varied across parameters. The classification was specific to ASD rather than neurodevelopmental conditions in general (e.g., attention deficit hyperactivity disorder). Our results confirm the hypothesis that the neuroanatomy of autism is truly multidimensional, and affects multiple and most likely independent cortical features. The spatial patterns detected using SVM may help further exploration of the specific genetic and neuropathological underpinnings of ASD, and provide new insights into the most likely multifactorial etiology of the condition.
Ecker
Christine
C
Section of Brain Maturation, Department of Psychological Medicine, Institute of Psychiatry, Brain Image Analysis Unit, Centre for Neuroimaging Sciences, King's College, London SE5 8AF, United Kingdom. Christine.ecker@kcl.ac.uk
Marquand
Andre
A
Mourão-Miranda
Janaina
J
Johnston
Patrick
P
Daly
Eileen M
EM
Brammer
Michael J
MJ
Maltezos
Stefanos
S
Murphy
Clodagh M
CM
Robertson
Dene
D
Williams
Steven C
SC
Murphy
Declan G M
DG
D000328:Adult; D000368:Aged; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications; D001321:Autistic Disorder / Q000175:diagnosis* / Q000503:physiopathology*; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000145:classification / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012720:Severity of Illness Index; D013223:Statistics as Topic; D055815:Young Adult