White-matter relaxation time and myelin water fraction differences in young adults with autism.
Psychol Med
; 45(4): 795-805, 2015 Mar.
Article
em En
| MEDLINE
| ID: mdl-25111948
ABSTRACT
BACKGROUND:
Increasing evidence suggests that autism is associated with abnormal white-matter (WM) anatomy and impaired brain 'connectivity'. While myelin plays a critical role in synchronized brain communication, its aetiological role in autistic symptoms has only been indirectly addressed by WM volumetric, relaxometry and diffusion tensor imaging studies. A potentially more specific measure of myelin content, termed myelin water fraction (MWF), could provide improved sensitivity to myelin alteration in autism.METHOD:
We performed a cross-sectional imaging study that compared 14 individuals with autism and 14 age- and IQ-matched controls. T 1 relaxation times (T 1), T 2 relaxation times (T 2) and MWF values were compared between autistic subjects, diagnosed using the Autism Diagnostic Interview - Revised (ADI-R), with current symptoms assessed using the Autism Diagnostic Observation Schedule (ADOS) and typical healthy controls. Correlations between T 1, T 2 and MWF values with clinical measures [ADI-R, ADOS, and the Autism Quotient (AQ)] were also assessed.RESULTS:
Individuals with autism showed widespread WM T 1 and MWF differences compared to typical controls. Within autistic individuals, worse current social interaction skill as measured by the ADOS was related to reduced MWF although not T 1. No significant differences or correlations with symptoms were observed with respect to T 2.CONCLUSIONS:
Autistic individuals have significantly lower global MWF and higher T 1, suggesting widespread alteration in tissue microstructure and biochemistry. Areas of difference, including thalamic projections, cerebellum and cingulum, have previously been implicated in the disorder; however, this is the first study to specifically indicate myelin alteration in these regions.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transtorno Autístico
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Imageamento por Ressonância Magnética
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Substância Branca
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Bainha de Mielina
Limite:
Adult
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Humans
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Male
Idioma:
En
Revista:
Psychol Med
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estados Unidos