Semrud-Clikeman, Margaret847449782008-08-282008-08-282006http://hdl.handle.net/2152/2589textThis study investigated the caudate nucleus, attention, and externalizing problems in children with 18q- before and after growth hormone (GH) treatment. Children with 18q- were referred for participation in this study by the Chromosome 18 Clinical Research Center. Thirteen participants with 18q- and 12 controls participated in the study. Volumetric analysis of the caudate nucleus using MRI revealed no significant differences in caudate volume and asymmetry among the 18q- participants pre and post treatment and controls. The 18q- participants and controls showed caudate symmetry (L = R), which is contrary to the L > R asymmetry expected in controls and post growth hormone participants. The 18q- participants, pre and post treatment, showed greater attention problems, although mild, than the control group. There was no difference in externalizing problems among the groups. No change in behavioral functioning with GH treatment was found in the 18q- participants. Caudate volumes were found to decrease with age in controls, but this age-related decrease was not observed in 18q- participants. This finding suggests a disruption in the neural system that likely has functional implications requiring further investigation. Results of this study will contribute to a greater understanding of the relationship between brain morphology and cognitive and behavioral functioning in 18q-.electronicengCopyright is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.Somatotropin--Physiological effectCaudate nucleusAttention-deficit hyperactivity disorderThesis