Affiliations: Department of Biological and Medical Psychology,
Faculty of Psychology, University of Bergen, Bergen, Norway | Department of Clinical Medicine, Faculty of Medicine
and Dentistry, University of Bergen, Bergen, Norway | K.G. Jebsen Centre for Research on Neuropsychiatric
Disorders, University of Bergen, Bergen, Norway | Center for Child and Adolescent Psychiatry Bispebjerg,
Capital Region Psychiatry, Bispebjerg, Denmark | Institute for Neurology, Psychiatry, and Sensory
Sciences, University of Copenhagen, Copenhagen, Denmark
Note: [] Corresponding author: Kerstin J. Plessen, MD, PhD, Mental Health
Centre for Child and Adolescent Psychiatry, Bispebjerg Bakke 30, 2400 Kbh,
Denmark. Tel.: +3864 1181; Fax: +3864 4487; E-mail:
[email protected]
Abstract: BACKGROUND: Tourette syndrome (TS) is a neuropsychiatric disorder
with childhood onset characterized by chronic motor and vocal tics. The typical
clinical course of an attenuation of symptoms during adolescence in parallel
with the emerging self-regulatory control during development suggests that
plastic processes may play an important role in the development of tic
symptoms. METHODS: We conducted a systematic search to identify existing
imaging studies (both anatomical and functional magnetic resonance imaging
[fMRI]) in young persons under the age of 19 years with TS. RESULTS: The final search resulted in 13 original studies, which
were reviewed with a focus on findings suggesting adaptive processes (using
fMRI) and plasticity (using anatomical MRI). Differences in brain activation
compared to healthy controls during tasks that require overriding of prepotent
responses help to understand compensatory pathways in children with TS. Along
with alterations in regions putatively representing the origin of tics,
deviations in several other regions most likely represent an activity-dependent
neural plasticity that help to modulate tic severity, such as the prefrontal
cortex, but also in the corpus callosum and the limbic system. DISCUSSION: Factors that potentially influence the development of
adaptive changes in the brain of children with TS are age, comorbidity with
other developmental disorders, medication use, IQ along with study-design or
MRI techniques for acquisition, and analysis of data. The most prominent
limitation of all studies is their cross-sectional design. Longitudinal studies
extending to younger age groups and to children at risk for developing TS
hopefully will confirm findings of neural plasticity in future
investigations.
Keywords: Tourette syndrome, children, Magnetic Resonance Imaging, neural plasticity, adaptation
