Gray and white matter imbalance – Typical structural abnormality underlying classic autism?

doi:10.1016/j.braindev.2007.11.006

Brain and Development

Volume 30, Issue 6, June 2008, Pages 396-401

https://doi.org/10.1016/j.braindev.2007.11.006 Get rights and content

Abstract

Recent evidence supports increased cortical activity and impaired brain connectivity in autism, but the structural correlates of these abnormalities are not yet defined. We performed a voxel based morphometry analysis of brain MRI from patients with autism selected from a group of 103 subjects with pervasive developmental disorders. Twelve male patients with mean age of 12.4 ± 4 years were compared with 16 matched controls. Patients with autism exhibited increase in gray matter in medial and dorsolateral frontal areas, in the lateral and medial parts of the temporal lobes, in the parietal lobes, cerebellum and claustrum. Patients also showed decrease in frontal, parietal, temporal and occipital white matter. The combination of enlarged cortex and reduced white matter is possibly the structural basis of some symptoms of classic autism.

Section snippets

1. Introduction

Autism is most likely caused by a disruption in the sophisticated cascade of events that take place during brain development. However, the functional and structural consequences of these altered steps are largely unclear. It is also unknown if these abnormalities are consistent across subjects with autism, therefore leading to the symptoms that characterize autism, or if convergent symptoms can arise from different brain abnormalities.

There is remarkably low reliability in reported brain

2. Methods

Patients with autism were selected form a large cohort composed of 103 patients with pervasive developmental disorder, described in detail elsewhere [15]. The diagnosis of autism was performed by a thorough neurological investigation composed by a comprehensive history, assessment and physical examination. In the present study, we only included those patients who fulfilled the diagnosis for autism as defined by the DSM-IV and ICD-10 criteria (Table 1). All individuals had normal results on

3. Results

We evaluated 12 subjects with classic autism. There was no significant difference in the mean age (t(26) = 0.6, p = 0.5) between the 16 controls and patients.

The results from the analysis are given in a parametric map of t-statistic (SPM(t)), and the SPM(t) is corrected for normal distribution (SPM(z)).There was a significant increase in regional gray matter and decrease in regional white matter in subjects with autism.

Increased gray matter in patients with autism was typically bilateral and

4. Discussion

The incidence and prevalence of autism have consistently increased over the past few decades [18], [19]. It is not clear if this is related to a true increase in frequency of the disorder, or to an increase in awareness, leading to more diagnosed cases. Regardless of the cause, the high incidence of autism greatly contrasts with the incomplete knowledge of its neurobiology.

In this manuscript, we provide evidence that adolescents and young adults with autism exhibit structural brain

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Original articleGray and white matter imbalance – Typical structural abnormality underlying classic autism?

Abstract

Section snippets

1. Introduction

2. Methods

3. Results

4. Discussion

Int J Dev Neurosci

Biol Psychiatry

Curr Opin Neurobiol

Neuroimage

Neuroimage

Neuroimage

Neuroimage

Biol Psychiatry

A clinicopathological study of autism

Brain

Neuroanatomic observations of the brain in autism

Minicolumnar pathology in autism

Neurology

Unusual brain growth patterns in early life in patients with autistic disorder: an MRI study

Neurology

Original article
Gray and white matter imbalance – Typical structural abnormality underlying classic autism?