Neuroimaging in Infantile Autism

Abstract

Metabolic findings using [18F]fluorodeoxyglucose (FDG) with positron emission tomography (PET) and correlative anatomic findings with computed tomography (CT) or magnetic resonance imaging (MRI) were characterized in 13 children with infantile autism. Four of 13 patients had both an abnormal FDG-PET and an abnormal MRI, whereas seven of 13 patients had both a normal FDG-PET and a normal CT or MRI. Sixteen of a total of 195 brain areas qualitatively examined with FDG-PET had a hypometabolic abnormality on PET. Three of the five abnormal structural imaging studies revealed neuronal migrational anomalies (focal pachygyria). In two of the five patients with anatomic abnormalities, these were noted only after knowledge of the FDG-PET findings. Our experience reveals that anatomic and metabolic abnormalities can be found in children who exhibit autistic behavior. An FDG-PET study may provide evidence of metabolic dysfunction after an initially unremarkable MRI scan because subtle anatomic abnormalities (as those seen with neuronal migrational anomalies) may be found only after knowledge of a regional metabolic abnormality.

A Microscopic Study of Language-Related Cortex in Autism

“…Kemper and Bauman (1993) reported a coarse and poorly-laminated cingulate cortex in autism andother authors have presented functional evidence of abnormal connections, as well as a delay in the maturation of some cortical circuits [9][10][11][12] . Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) scans of autistic subjects suggest cortical ectopias, a distinctive feature of altered neuronal migration [10,[13][14][15] . The present study found no deviation from normal cortical layering pattern, evidence of ectopic cells, nor differences in the relative thickness of cortical layers in areas 22, 39 and 44 of brain from autistic subjects.…”

Functional neuroimaging of autistic disorders

“…An uncontrolled, resting-state study of 13 autistic children (nine male, ages 4 -11 years) with comorbid mental retardation and seizure disorders qualitatively identified abnormalities, primarily hypometabolic foci, in five of the 13 children [Schifter et al, 1994]. The parietal, temporal, and occipital lobes were most frequently affected, followed by the thalami and cerebellum.…”

Regional cerebral blood flow in childhood autism: a SPET study with SPM evaluation

“…Morphological investigations utilizing computed tomography (CT) and magnetic resonance imaging (MRI) have described several brain abnormalities without demonstrating any concordance in dysfunctions [6][7][8][9][10][11]. An interesting approach to detection comes from findings which suggest an anomalous hemispheric specialization [12][13][14][15].…”