Functional neuroimaging of autistic disorders

Area of Science:

• Neuroscience
• Developmental Psychology
• Psychiatry

Background:

• Autism spectrum disorder (ASD) presents complex neurobiological challenges.
• Functional neuroimaging offers insights but faces practical and scientific hurdles.
• Previous studies show inconsistent findings in brain metabolism and blood flow, indicating significant variability.

Purpose of the Study:

• To review current functional neuroimaging findings in ASD.
• To identify challenges and future research directions in the neurobiology of autism.

Main Methods:

• Review of studies using positron emission tomography (PET), magnetic resonance spectroscopy (MRS), and magnetoencephalography.
• Analysis of activation studies examining brain organization for language and cognition.
• Consideration of neurotransmitter and metabolic investigations.

Main Results:

• Variability in regional cerebral synaptic activity observed.
• Idiopathic autism patients less likely to show abnormalities than those with comorbidities.
• Alterations in brain organization for language/cognition suggested by activation studies.
• Abnormalities in serotonergic and dopaminergic function noted via PET.
• Metabolic deficits in frontal cortex and cerebellum documented by MRS.
• High incidence of epileptiform activity suggested by magnetoencephalography.

Conclusions:

• Functional neuroimaging is crucial for understanding ASD neurobiology.
• Future research should focus on well-controlled developmental studies of homogeneous subgroups.
• Priorities include investigating serotonergic/dopaminergic systems, limbic-emotional networks, and epileptiform activity.