Brainstem volumetric alterations in children with autism

Background. Although several studies have examined brainstem volume in autism, results have been mixed and no investigation has specifically measured gray- and white-matter structures. The aim of this investigation was to assess gray- and white-matter volumes in children with autism. Method. Subjects included 22 right-handed, non-mentally retarded boys with autism and 22 gender- and age-matched controls. Magnetic resonance imaging (MRI) scans were obtained using a 1.5-T scanner and volumetric measurements were performed using the BRAINS2 software package. Gray- and white-matter volumes were measured using a semi-automated segmentation process. Results. There were no significant differences in age and total brain volume (TBV) between the two groups but full-scale IQ was higher in controls. A decrease in brainstem gray-matter volume was observed in the autism group before and after controlling for TBV. No significant differences were observed in white-matter volume. A significant relationship was observed between brainstem gray-matter volume and oral sensory sensitivity as measured by the Sensory Profile Questionnaire (SPQ). Conclusions. Findings from this study are suggestive of brainstem abnormalities in autism involving gray-matter structures with evidence supporting the existence of a relationship between these alterations and sensory deficits. These results are consistent with previous investigations and support the existence of disturbances in brainstem circuitry thought to be implicated in the sensory dysfunction observed in autism.