Structural studies |
|
|
|
|
Peterson et al., 2003
|
Volumetric MRI |
154 |
Reduced caudate volume in TS |
Post hoc analyses by age, meds, comorbidity |
Hyde et al., 1995
|
Volumetric MRI |
10 |
Reduced right caudate volume correlated with symptom severity |
Twin study; no control for age, treatment, or common comorbidities |
Bloch et al., 2005
|
Volumetric MRI |
43 |
Caudate volume in childhood varies inversely with tic severity in adulthood |
Longitudinal design; includes assessment of OCD but not ADHD effects; no follow-up imaging |
Roessner et al., 2011
|
Volumetric MRI |
49 |
Enlarged putamen and corpus callosum in TS |
Children/adolescents only, controlled for age and IQ; exclusion criteria included prior treatment and comorbid ADHD/OCD |
Kassubek et al., 2006
|
Voxel-based morphometry |
14 |
Enlarged putamen in TS |
Children only; controlled for age and gender, not treatment; assessed ADHD but not OCD effects |
Singer et al., 1993
|
Volumetric MRI |
37 |
Altered hemispheric asymmetry of putamen and globus pallidus |
Children only; controlled for age; post hoc analysis of ADHD comorbidity |
Zimmerman et al., 2000
|
Volumetric MRI |
19 |
No putamen asymmetry in girls with TS |
Controlled for age; assessed for ADHD effect |
Makki et al., 2008
|
Diffusion tensor imaging |
23 |
Microstructural abnormalities in thalamus in TS |
Controlled for age; no analysis of medication or comorbidity effects |
Neuner et al., 2011
|
Diffusion tensor imaging |
28 |
Correlation of BG diffusivity and symptom severity |
Adults only; excluded comorbidities |
Peterson et al., 2007
|
Volumetric MRI |
154 |
Larger hippocampus and amygdala in TS |
Post hoc analyses by age, meds, comorbidity |
Peterson et al., 2001
|
Volumetric MRI |
155 |
Enlarged dorsofrontal and parieto-occipital cortices; diminished inferior occipital cortex |
Post hoc analyses by age, meds, comorbidity |
Müller-Vahl et al., 2009
|
Voxel-based morphometry |
19 |
Decreased prefrontal, sensorimotor, anterior cingulate, and left caudate gray matter; decreased white matter in right inferior frontal gyrus, left superior frontal gyrus, and anterior corpus callosum |
Adult males only; untreated at least 1 year; no significant comorbidities in population |
Müller-Vahl et al., 2009
|
Magnetization transfer imaging |
19 |
White matter reductions in right medial frontal gyrus, inferior frontal gyrus bilaterally, and right cingulate gyrus |
Adult males only; untreated at least 1 year; no significant comorbidities in population |
Baumgardner et al., 1996
|
Volumetric MRI |
37 |
Larger corpus callosum in TS |
Children; controlled for age, gender, overall brain volume |
Mostofsky et al., 1999
|
Volumetric MRI |
19 |
No difference in corpus callosum |
Girls only; assessed effect of ADHD comorbidity |
Plessen et al., 2004
|
Volumetric MRI |
158 |
Alterations of corpus callosum, variable with age |
Post hoc analyses by age, meds, comorbidity |
Cavanna et al., 2010
|
DTI |
1 |
Lower fractional anisotropy of corpus callosum |
Twin comparison |
Draganski et al., 2010
|
Voxel-based morphometry and DWI |
40 |
Cortical thinning diffusely, modulated based on comorbidity and symptom severity; increases in primary somatosensory cortex correlated with premonitory sensations |
Post hoc analysis of comorbidities; infers ongoing structural plasticity based on a single study |
Jackson et al., 2011
|
DWI |
13 |
Diffuse abnormalities in white matter microstructure; enhanced motor control in TS patients |
Adults; excluded comorbidities; wide range of tic severity |
Functional studies |
|
|
|
|
Ziemann et al., 1997
|
Transcranial magnetic stimulation |
20 |
Shortened cortical silent period and reduced intracortical inhibition |
Adolescent/adult; post hoc analysis by age, sex, comorbidity, and treatment |
Moll et al., 1999
|
Transcranial magnetic stimulation |
21 |
Shortened cortical silent period |
Children; post hoc analyses of age, OCD, neuroleptic treatment |
Gilbert et al., 2004
|
Transcranial magnetic stimulation |
36 |
Correlation of cortical disinhibition with tic and ADHD severity |
Children and adults; assessed effects of ADHD and OCD comorbidities |
Stern et al., 2000
|
PET |
6 |
Tic correlation with activity in cortex, putamen, and caudate |
Adults; no control for medication; no discussion of comorbidity |
Peterson et al., 1998
|
fMRI |
22 |
Increased cortical activity with decreased striatal and thalamic activity during active tic suppression |
Adults; post hoc analyses of gender, treatment, and comorbidity |
Braun et al., 1993
|
PET |
16 |
Increased activity of sensorimotor cortex; reduction of activity in limbic cortex and striatum |
Adults; nonmedicated |
Eidelberg et al., 1997
|
PET |
10 |
Increased activity in sensorimotor cortex; decreased in caudate and thalamus |
Adults; nonmedicated; no assessment of comorbidity effects |
Biswal et al., 1998
|
fMRI |
5 |
Increased motor cortex activity during voluntary motor tasks in TS |
Adults, few from same pedigree; variable severity and comorbidities |
Church et al., 2009b
|
fMRI |
33 |
Abnormal maturation of functional networks |
Adolescents; included comorbidities |
Marsh et al., 2007
|
fMRI |
66 |
Abnormal age-related activation of neural circuits |
Adults and children; post hoc analysis of medication and comorbidity effects |
Baym et al., 2008
|
fMRI |
18 |
Tic severity correlated with enhanced activation of dopaminergic nuclei and slower response time |
Children; mostly medication-naive; post hoc analysis of comorbidity; |
Neurotransmitter studies |
|
|
|
|
Wong et al., 2008
|
PET |
16 |
Increased phasic dopamine release in ventral striatum |
Adults; included assessment of OCD comorbidity |
Steeves et al., 2010
|
PET |
8 |
More widespread phasic dopamine release compared to controls |
Adults; controlled for medication exposure and comorbidity |
Liu et al., 2010
|
SPECT |
18 |
Higher dopamine transporter expression |
Adolescents and adults; drug-naive; no discussion of comorbidities |
Behen et al., 2007
|
PET |
29 |
Abnormal tryptophan metabolism in dorsolateral prefrontal cortex and thalamus |
Children; subgroup analyses of medication and comorbidities |
Haugbøl et al., 2007
|
PET |
20 |
Increased serotonin receptor binding in TS |
Adult; no assessment of medication or comorbidity effects |