Biomedical subjects
Katherine D Tsatsanis
Publications and source records attributed to Katherine D Tsatsanis.
Reduced thalamic volume in high-functioning individuals with autism.
BACKGROUND: In this study, specific consideration is given to a role for the thalamus in autism. METHODS: A volumetric analysis of the thalamus was conducted using magnetic resonance imaging, based on segmentation of continuous 1.2 mm(3) coronal images. The sample consisted of 12 high-functioning individuals with autism, mean age of 21.0 years (SD = 10.4) and mean IQ of 106.4 (SD = 18.3). Normal control subjects were selected to match this group; the mean age was 18.1 years (SD = 6.3); mean IQ was 108.8 (SD = 15.6). RESULTS: Unadjusted mean thalamic volume was not significantly different; however, there were significant differences in the relationship between thalamic volume and total brain volume (TBV). The correlation was strong and positive in the control group but statistically nonsignificant in the autism group. Group differences were found when adjustments were made for TBV, achieved by grouping subjects' measurements on this variable using a split median procedure. Mean thalamic volume was significantly reduced in the autism group relative to normal control subjects, specifically within the high TBV group. CONCLUSION: The increase in thalamic volume with increase in TBV was not seen in autism, suggesting underdeveloped connections between cortical and subcortical regions and indicating a need to examine this structure further.
Outcome research in Asperger syndrome and autism.
This article presents findings from the outcome literature on autism, Asperger syndrome (AS), and related disorders. The discussion of outcome principally focuses on life adaptation, but also considers outcome in AS in relationship to other diagnostic groups and across time. The current research in this area is neither substantial nor systematic. Thus, in this examination of the literature, the goal is to highlight salient findings, but also to put forward questions that might direct meaningful research in this area for the future and to consider implications for treatment.
Concurrent validity and classification accuracy of the Leiter and Leiter-R in low-functioning children with autism.
The concurrent validity of the Leiter International Performance Scale (Leiter) and Leiter International Performance Scale-Revised (Leiter-R) was examined in a sample of children with autism who could not be assessed with more traditional measures of intelligence (e.g., the Wechsler scales). The sample consisted of 26 children ranging in age from 4 to 16 years. The correlation between the Leiter scales was high (r = .87), and there was a difference of 3.7 points between the two mean scores, nonsignificant at both statistical and clinical levels. However, significant intraindividual discrepancies were present in 10 cases, 2 of which were both large (24 and 36 points) and clinically meaningful. The mean profile of performance on Leiter-R subtests is also presented for this sample of children with autism, to allow for comparison with other groups. Based on the results of this initial evaluation, together with the current normative data, good psychometric properties, and availability of global and subtest scores with the Leiter-R, the instrument is generally recommended for use with children with autism. However, because of changes in the design of the Leiter-R, there may be greater clinical success with the original Leiter for those children who are very low functioning and severely affected, particularly younger children.