Poster #44 - Cerebellar Vermis Volume in Children with RD and/or ADHD

• In Event: 2-110 - Poster Session 07
  In Poster Session: PS 07 Section - Developmental Disabilities

Integrative Statement

Previous literature has implicated the cerebellum in various forms of cognition such as attention (Gottwald, Mihajlovic, Wilde, & Mehdor, 2003). Due to its connections to the basal ganglia and prefrontal cortex, cerebellar dysfunction has been implicated in ADHD (Bledsoe, Semrud-Clikeman, & Pliszka, 2009). Indeed, a 1998 study found a significant reduction in vermal in lobules VIII to X (posterior inferior vermis) in boys with ADHD (Berquin, Giedd, Jacobsen, Hamburg, Krain, Rapoport, & Castellanos, 1998). Similarly, Blesdoe and colleagues (2009) found a volume reduction in vermal lobules VIII to X. In addition, in individuals with autism neuroimaging studies have demonstrated hypoplasia in vermal lobules VI to VII (Akshoomoff, Courchesne, & Townsend, 1997). This area is believed to play a role in attentional shift. Difficulties concerning attention is part of the clinical definition of ADHD. However, children with ADHD have not been shown to have a reduction in vermal lobules VI to VII (Bledsoe, Semrud-Clikeman, & Pliszka, 2009). Further, RD is often co-morbid with ADHD (Germanó, Gagliano, & Curatolo, 2010), but children with RD have been shown to have atypical volume in the cerebellar hemispheres instead (Kibby, Fancher, Markanen, & Hynd, 2008). Given the variability of findings on the vermis in neurodevelopmental disorders, the goal of this study was to determine whether vermal volume in lobules VI-VII and VIII-X differs between children with RD, ADHD, co-morbid RD/ADHD, and typically developing controls.

Data was collected from a community sample in larger studies. For this project, the sample included 98 children (27 controls, 39 with ADHD, 16 with RD, and 16 with co-morbid ADHD and RD), 8 to 12 years of age, with sufficient scanning resolution for data analysis. 3-D T1 images were collected on all participants. Regions of interest (ROI) were found using Voxel Based Morphology (VBM). One-way ANOVA was used to determine whether age, gender, total intracranial volume (TICV), and handedness should be used as covariates. Of these, only handedness was significant, F(3, 94)=3.32, p=.023. From there, a MANCOVA was performed including both the left and right lobules VI-VII and VIII-X. No significant differences between groups were found, Wilks’ Λ=.83, F(12, 238)=1.47, p=.136, partial eta squared=.061. Group means are shown in Table 1.

Vermal volume did not differ between groups for lobules VI-VII or VIII-X. However, this result may be due to the small sample size, especially for the RD groups, although vermal volumes are not as commonly affected in RD (see Kibby et al., 2008). The lack of group differences is more surprising for the ADHD group. It may be due to the method of measurement used. Other methods, such as manual tracing, may yield different results, as tracing is performed in the brain’s native space whereas VBM is not. It also may be due to the heterogeneity of etiology within ADHD, with only some children with the disorder having posterior vermis hypoplasia.

Authors

• Emily A. Caminiti, Southern Illinois University-Carbondale
  Presenting Author

• Audreyana C. Jagger-Rickels, Southern Illinois University-Carbondale
  Non-Presenting Author

• Michelle Y. Kibby, Southern Illinois University-Carbondale
  Non-Presenting Author