A pilot study of basal ganglia and thalamus structure by high dimensional mapping in children with Tourette syndrome.
BACKGROUND
Prior brain imaging and autopsy studies have suggested that structural abnormalities of the basal ganglia (BG) nuclei may be present in Tourette Syndrome (TS). These studies have focused mainly on the volume differences of the BG structures and not their anatomical shapes.  Shape differences of various brain structures have been demonstrated in other neuropsychiatric disorders using large-deformation, high dimensional brain mapping (HDBM-LD).  A previous study of a small sample of adult TS patients demonstrated the validity of the method, but did not find significant differences compared to controls. Since TS usually begins in childhood and adult studies may show structure differences due to adaptations, we hypothesized that differences in BG and thalamus structure geometry and volume due to etiological changes in TS might be better characterized in children.


OBJECTIVE
Pilot the HDBM-LD method in children and estimate effect sizes.


METHODS
In this pilot study, T1-weighted MRIs were collected in 13 children with TS and 16 healthy, tic-free, control children. The groups were well matched for age.  The primary outcome measures were the first 10 eigenvectors which are derived using HDBM-LD methods and represent the majority of the geometric shape of each structure, and the volumes of each structure adjusted for whole brain volume. We also compared hemispheric right/left asymmetry and estimated effect sizes for both volume and shape differences between groups.


RESULTS
We found no statistically significant differences between the TS subjects and controls in volume, shape, or right/left asymmetry.  Effect sizes were greater for shape analysis than for volume.


CONCLUSIONS
This study represents one of the first efforts to study the shape as opposed to the volume of the BG in TS, but power was limited by sample size. Shape analysis by the HDBM-LD method may prove more sensitive to group differences.
Washington University School of Medicine, St. Louis, MO 63110, USA.
Alton C
AC
Williams
Division of Biology and Biomedical Sciences, Washington University, St. Louis, MO 63110, USA ; Current affiliation: Centene Corporation, St. Louis, MO 63105, USA.
Marie E
ME
McNeely
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Deanna J
DJ
Greene
Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Current affiliation: Department of Psychology in The College of Liberal, University of Texas- Austin, Austin, TX 78712, USA.
Jessica A
JA
Church
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA ; Current affiliation: Department of Mental Health, St. Louis VA Medical Center, St. Louis, MO 63110, USA.
Stacie L
SL
Warren
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Johanna M
JM
Hartlein
Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Anatomy & Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA.
Bradley L
BL
Schlaggar
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA ; Department of Anatomy & Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Kevin J
KJ
Black
Department of Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA ; Current affiliation: Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine Chicago, Chicago, IL 60611, USA ; Current affiliation: Department of Radiology, Northwestern University Feinberg School of Medicine Chicago, Chicago, IL 60611, USA.
Lei
L
Wang