Subjects with intellectual disability and familial need for full-time special education show regional brain alterations: a voxel-based morphometry study.

Subjects attending full-time special education (SE) often have multifactorial background for their cognitive impairment, and brain MRI may show nonspecific changes. As voxel-based morphometry reveals regional volume differences, we applied this method to 119 subjects with cognitive impairments and familial need for full-time SE--graded into three levels from specific disorders of cognitive processes (level 1) to intellectual disability (IQ <70; level 3)--and to 43 age-matched controls attending mainstream education (level 0). Subjects in SE groups had smaller global brain white matter (WM), cerebrospinal fluid, and total brain volume than controls. Compared with controls, subjects with intellectual disabilities in SE level 3 showed greater regional gray matter volumes bilaterally in the ventral and dorsal anterior cingulate cortex and smaller regional gray matter volumes in the left thalamus and cerebellar hemisphere. Further, they had greater WM volume in the left frontoparietal region and smaller WM volumes in the posterior limbs of the internal capsules. Subjects in SE level 1 and 2 groups showed the same tendency, but the results were nonsignificant. In conclusion, compared with controls, subjects with intellectual disabilities showed in voxel-based morphometry analysis several regional brain alterations.

Newborns at risk for special education placement: a population-based study.

OBJECTIVES: To establish the contributions of birth weight (BW), gender, socioeconomic status (SES), and parental age on risks for special education (SE) placements in school-age children. METHODS: A population-based sample of 900 school-age children attending the following full-time SE groups: at level 1, children had isolated neurodevelopmental, physical, or other impairments; at level 2, borderline to mild intellectual disability (ID); and at level 3, moderate to severe ID. Three hundred and one children enrolled in mainstream education formed the control group (level 0). For all children with siblings, we defined familiar forms of learning disorders as having a sibling in one of the SE groupings. We performed our analysis for the entire cohort as well as comparing risk factors within the familial and non-familial types of SE groupings. RESULTS: In multinomial logistic regression analysis, age of father 40 years, low BW (<2500g or <-2 SD), male sex, and parent's lower SES, all increased the probability of SE placement. In the familial forms of levels 2 and 3, the parental SES was lower and, in addition, in the level 2, the family size was bigger. Furthermore, in the non-familial form of level 2, both the low and the high (4000g) BW were more common. CONCLUSIONS: Among the known risk factors for learning disabilities (LD), our study highlighted the importance of a higher paternal age and a lower SES especially in the familial forms of LD.