Publications
Text queries can be conducted by Author, Title, or Keyword.
Cerebellar vermis lobules VIII-X in autism
Source: Progress in Neuropsychopharmacology and Biological 1999 May;23(4):625-633.
Author: Levitt JG, Blanton R, Capetillo-Cunliffe L, Guthrie D, Toga A, McCracken JT.
PubMed ID: 10390721
Abstract:
ABSTRACT: 1. The aim was to investigate cerebellar vermis cross-sectional area in a group of high-functioning autistic children and normal contrl children. 2. Cerebellar vermis area measurements were completed on MRI scans from 8 autistic children (mean age 12.5 plus or minus 2.2, mean IQ 83.3 plus or minus 11.9) and 21 normal children (mean age 12.0 plus or minus 2.8, mean IQ 115 plus or minus 11). 3. The area of cerebellar vermis lobules VII-X was significantly smaller in autistic children than in the normal control subjects. ANCOVA demonstrated a confounding effect of IQ on these results. 4. Larger studies of autistic and normal subjects will be needed to assess the relationship between cerebellar abnormalities, autisitic symptoms and IQ. INTRODUCTION: Autism is a severe developmental disorder of communication and reciprocal social interaction with repetitive, odd behaviors. While the underlying neurobiology of autism remains unknown, histoanatomic investigations have demonstrated cellular abnormalities in the limbic system and cerebella of autistic subjects. A variety of MRI studies have also demonstrated neuroanatomic abnormalities in autistic subjects such as increased brain size, irregularities of the cerebral cortical surface, and posterior fossa abnormalities in areas including the pons, fourth ventricle and cerebellar vermal lobules VI and VIII. METHODS: This pilot study was performed on 8 children with autism and 21 normal subjects. All subjects completed MRI scans performed on a 1.5 Tesla Signa MR scanner using a coronal SPGR sequence of 42/5/1 or 43/6/1 (repetition time/echo time/excitations). The image data was digitally transformed into the Talairach coordinate system using the anterior and posterior commissures as the center of origin, then resliced into 1 mm sections. Data analysis was performed with analysis of variance (ANOVA)using cerebellar vermis area of lobules I-V, VI-VII and VIII-X as the dependent variables and group (normal vs. autistic) as the between groups variable. Additionally, effect size was calculated as an indication of the magnitude of the differences found by ANOVA. Two analyses of covariance were run, one using IQ as a covariate, the other using age as the covariate. RESULTS: ANOVA revealed a significant difference in the area of vermis lobules VIII-X with the normal group having a significantly larger area of lobules VIII-X than the autistic group. There were no statistically significant differences between groups in area of lobules I-V or VI-VIII. The effect size revealed a discrepancy between the values of the two means that was greater than one standard deviation. CONCLUSION: In this pilot study, we found a significant difference in the size of cerebellar vermis lobules VIII-X between autistic subjects and normal control subjects. The analysis of covariance demonstrated a confounding effect of IQ upon these results. These findings, although preliminary, support those of other studies suggesting that IQ might play a role in the association between autism and vermal hypoplasia.
Source: Progress in Neuropsychopharmacology and Biological 1999 May;23(4):625-633.
Author: Levitt JG, Blanton R, Capetillo-Cunliffe L, Guthrie D, Toga A, McCracken JT.
PubMed ID: 10390721
Abstract:
ABSTRACT: 1. The aim was to investigate cerebellar vermis cross-sectional area in a group of high-functioning autistic children and normal contrl children. 2. Cerebellar vermis area measurements were completed on MRI scans from 8 autistic children (mean age 12.5 plus or minus 2.2, mean IQ 83.3 plus or minus 11.9) and 21 normal children (mean age 12.0 plus or minus 2.8, mean IQ 115 plus or minus 11). 3. The area of cerebellar vermis lobules VII-X was significantly smaller in autistic children than in the normal control subjects. ANCOVA demonstrated a confounding effect of IQ on these results. 4. Larger studies of autistic and normal subjects will be needed to assess the relationship between cerebellar abnormalities, autisitic symptoms and IQ. INTRODUCTION: Autism is a severe developmental disorder of communication and reciprocal social interaction with repetitive, odd behaviors. While the underlying neurobiology of autism remains unknown, histoanatomic investigations have demonstrated cellular abnormalities in the limbic system and cerebella of autistic subjects. A variety of MRI studies have also demonstrated neuroanatomic abnormalities in autistic subjects such as increased brain size, irregularities of the cerebral cortical surface, and posterior fossa abnormalities in areas including the pons, fourth ventricle and cerebellar vermal lobules VI and VIII. METHODS: This pilot study was performed on 8 children with autism and 21 normal subjects. All subjects completed MRI scans performed on a 1.5 Tesla Signa MR scanner using a coronal SPGR sequence of 42/5/1 or 43/6/1 (repetition time/echo time/excitations). The image data was digitally transformed into the Talairach coordinate system using the anterior and posterior commissures as the center of origin, then resliced into 1 mm sections. Data analysis was performed with analysis of variance (ANOVA)using cerebellar vermis area of lobules I-V, VI-VII and VIII-X as the dependent variables and group (normal vs. autistic) as the between groups variable. Additionally, effect size was calculated as an indication of the magnitude of the differences found by ANOVA. Two analyses of covariance were run, one using IQ as a covariate, the other using age as the covariate. RESULTS: ANOVA revealed a significant difference in the area of vermis lobules VIII-X with the normal group having a significantly larger area of lobules VIII-X than the autistic group. There were no statistically significant differences between groups in area of lobules I-V or VI-VIII. The effect size revealed a discrepancy between the values of the two means that was greater than one standard deviation. CONCLUSION: In this pilot study, we found a significant difference in the size of cerebellar vermis lobules VIII-X between autistic subjects and normal control subjects. The analysis of covariance demonstrated a confounding effect of IQ upon these results. These findings, although preliminary, support those of other studies suggesting that IQ might play a role in the association between autism and vermal hypoplasia.