Cerebellar function in autism: functional magnetic resonance image activation during a simple motor task.
BACKGROUND
The cerebellum is one of the most consistent sites of neuroanatomic abnormality in autism, yet it is still unclear how such pathology impacts cerebellar function. In normal subjects, we previously demonstrated with functional magnetic resonance imaging (fMRI) a dissociation between cerebellar regions involved in attention and those involved in a simple motor task, with motor activation localized to the anterior cerebellum ipsilateral to the moving hand. The purpose of the present investigation was to examine activation in the cerebella of autistic patients and normal control subjects performing this motor task.


METHODS
We studied eight autistic patients and eight matched normal subjects, using fMRI. An anatomic region-of-interest approach was used, allowing a detailed examination of cerebellar function.


RESULTS
Autistic individuals showed significantly increased motor activation in the ipsilateral anterior cerebellar hemisphere relative to normal subjects, in addition to atypical activation in contralateral and posterior cerebellar regions. Moreover, increased activation was correlated with the degree of cerebellar structural abnormality.


CONCLUSIONS
These findings strongly suggest dysfunction of the autistic cerebellum that is a reflection of cerebellar anatomic abnormality. This neurofunctional deficit might be a key contributor to the development of certain diagnostic features of autism (e.g., impaired communication and social interaction, restricted interests, and stereotyped behaviors).
Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Greg
G
Allen
Ralph-Axel
RA
Müller
Eric
E
Courchesne
D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D002531:Cerebellum / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance / Q000502:physiology*; D012044:Regression Analysis
D010100:Oxygen