A Functional Magnetic Resonance Imaging Study of a Large Clinical Cohort of Children With Tourette Syndrome
Pediatric Department, Glostrup University Hospital, Glostrup, Denmark. Journal of child neurology
(Impact Factor: 1.72).
04/2011; 26(5):560-9. DOI: 10.1177/0883073810387928
There is evidence that cortico-striato-thalamo-cortical pathways are involved in the pathophysiology of Tourette syndrome. During the performance of neuropsychological tests in subjects with Tourette syndrome there are suggestions for increased activity in the sensimotor cortex, supplementary motor areas, and frontal cortex. To replicate findings, the authors examined 22 medication-naive children with Tourette syndrome only, 17 medication-naive children with Tourette syndrome and comorbidity, and 39 healthy controls with functional magnetic resonance imaging (MRI). There were no differences in activation in brain regions between the children with Tourette syndrome (divided according to the presence of comorbidity) and healthy controls after correction for the confounders age, sex, and intelligence. Activation in the cingulated gyrus, temporal gyrus, and medial frontal gyrus was correlated significantly with obsessive-compulsive disorder score. The authors did not find significant correlations between activation patterns and age, sex, duration of disease, intelligence, severity of tics, and attention-deficit hyperactivity disorder (ADHD) score.
Available from: Kevin John Black
- "There is some evidence for atypical and immature task control systems in the brain in TS/CTD (Church et al., 2009a, 2009b; Wang et al., 2011) as well as atypical activation of frontostriatal regions posited to support inhibitory control (Aron et al., 2014) in TS/CTD (Hershey et al., 2004a; Marsh et al., 2007; Baym et al., 2008; Raz et al., 2009). However, the directions of specific effects were inconsistent among the fMRI studies, and others have not been able to replicate differences between TS/CTD and controls with similar study designs (Hershey et al., 2004b; Debes et al., 2011). EEG and fMRI studies specifically investigating tic suppression have shown increased activation in frontostriatal regions that support inhibitory control during active tic suppression in children and adults with TS/CTD (Peterson et al., 1998; Hong et al., 2013). "
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ABSTRACT: Tic disorders are childhood onset neuropsychiatric disorders characterized by motor and/or vocal tics. Research has demonstrated that children with chronic tics (including Tourette syndrome and Chronic Tic Disorder: TS/CTD) can suppress tics, particularly when an immediate, contingent reward is given for successful tic suppression. As a diagnosis of TS/CTD requires tics to be present for at least one year, children in these tic suppression studies had been living with tics for quite some time. Thus, it is unclear whether the ability to inhibit tics is learned over time or present at tic onset. Resolving that issue would inform theories of how tics develop and how behavior therapy for tics works. We investigated tic suppression in school-age children as close to the time of tic onset as possible, and no later than six months after onset. Children were asked to suppress their tics both in the presence and absence of a contingent reward. Results demonstrated that these children, like children with TS/CTD, have some capacity to suppress tics, and that immediate reward enhances that capacity. These findings demonstrate that the modulating effect of reward on inhibitory control of tics is present within months of tic onset, before tics have become chronic
Available from: Pierpaolo Alongi
- "It is of note that the exact etiology of GTS remains unknown. Volumetric MRI in GTS provided evidence for correlations between tic severities and volume of specific structures [e.g., caudate, see Ref. (47)] and also for abnormal gray matter volumes in prefrontal cortex in children and adults [see Ref. (48, 49), and for review see Ref. (50, 51)]. Functional neuroimaging techniques, such as single-photon emission computed tomography (SPECT), PET, and fMRI have provided some evidence for the underlying pathological mechanisms in GTS that enabled new hypotheses on its pathophysiology to be formulated (50, 51). "
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ABSTRACT: Primary Dystonia (pD) is a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Gilles de la Tourette Syndrome (GTS) is a childhood-onset neuropsychiatric developmental disorder characterised by motor and phonic tics, which could progress to behavioural changes. GTS and obsessive-compulsive disorders (OCD) are often seen in comorbidity, also suggesting a possible overlap in the pathophysiological bases of these two conditions. PET techniques are of considerable value in detecting functional and molecular abnormalities in vivo, according to the adopted radioligands. For example, PET is the unique technique that allows in vivo investigation of neurotransmitter systems, providing evidence of changes in GTS or pD. For example, presynaptic and postsynaptic dopaminergic studies with PET have shown alterations compatible with dysfunction or loss of D2-bearing neurons, increased synaptic dopamine levels, or both. Measures of cerebral glucose metabolism with 18F-fluorodeoxyglucose (18F-FDG PET) are very sensitive in showing brain functional alterations as well. 18F-FDG PET data have shown metabolic changes within the cortico-striato-pallido-thalamo-cortical and cerebello-thalamo-cortical networks, revealing possible involvement of brain circuits not limited to basal ganglia in pD and GTS. The aim of this work is to overview PET consistent neuroimaging literature on pD and GTS that has provided functional and molecular knowledge of the underlying neural dysfunction. Furthermore we suggest potential applications of these techniques in monitoring treatments.
- "Relatedly, in a study of the Stroop interference task, Marsh and colleagues found that children and adults with TS co-opt controlrelated regions, including fronto-striatal regions, to maintain successful task performance, resulting in greater activity in those regions in the TS groups during the task (Marsh et al., 2007). Recently, however, Debes et al. (2011) failed to find any cortical differences specific to TS in children when controlling for age, sex, and IQ, and directly testing executive function tasks (e.g., Stroop, Go/No-go). In summary, functional MRI studies of controlled motor or cognitive tasks largely demonstrate some differences in both cortical and subcortical regions between unaffected participants and those with TS, perhaps revealing ways in which the brain is affected by, or compensating for, TS. "
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ABSTRACT: Tourette syndrome has been examined using many different neuroimaging techniques. There has been a recent surge of neuroimaging research papers related to Tourette syndrome that are exploring many different aspects of the disorder and its comorbidities. This brief review focuses on recent MRI-based imaging studies of pediatric Tourette syndrome, including anatomical, functional, resting state, and diffusion tensor MRI techniques. Consistencies across studies are explored, and particularly important issues involved in acquiring data from this special population are discussed.
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