title: Fronto-striatal glutamate in children with Tourette's disorder and attention-deficit/hyperactivity disorder.
abstract: Both Tourette's disorder (TD) and attention-deficit/hyperactivity disorder (ADHD) have been related to abnormalities in glutamatergic neurochemistry in the fronto-striatal circuitry. TD and ADHD often co-occur and the neural underpinnings of this co-occurrence have been insufficiently investigated in prior studies.
  
  
  
  We used proton magnetic resonance spectroscopy (1H-MRS) in children between 8 and 12 years of age (TDn= 15, ADHDn= 39, TD + ADHDn= 29, and healthy controlsn= 53) as an in vivo method of evaluating glutamate concentrations in the fronto-striatal circuit. Spectra were collected on a 3 Tesla Siemens scanner from two voxels in each participant: the anterior cingulate cortex (ACC) and the left dorsal striatum. LC-model was used to process spectra and generate glutamate concentrations in institutional units. A one-way analysis of variance was performed to determine significant effects of diagnostic group on glutamate concentrations.
  
  
  
  We did not find any group differences in glutamate concentrations in either the ACC (F(3132)= 0.97,p= 0.41) or striatum (F(3121)= 0.59,p= 0.62). Furthermore, variation in glutamate concentration in these regions was unrelated to age, sex, medication use, IQ, tic, or ADHD severity. Obsessive-compulsive (OC) symptoms were positively correlated with ACC glutamate concentration within the participants with TD (rho = 0.35,puncorrected= 0.02).
  
  
  
  We found no evidence for glutamatergic neuropathology in TD or ADHD within the fronto-striatal circuits. However, the correlation of OC-symptoms with ACC glutamate concentrations suggests that altered glutamatergic transmission is involved in OC-symptoms within TD, but this needs further investigation.
authors.affiliation: Department of Cognitive Neuroscience, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Jilly
authors.initials: J
authors.lastname: Naaijen
authors.affiliation: Department of Cognitive Neuroscience, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands.
authors.forename: Natalie J
authors.initials: NJ
authors.lastname: Forde
authors.affiliation: King's College London, Institute of Psychiatry, Psychology and Neuroscience, Department of Neuroimaging, London, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Lythgoe
authors.affiliation: Department of Cognitive Neuroscience, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Sophie E A
authors.initials: SE
authors.lastname: Akkermans
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands.
authors.forename: Thaira J C
authors.initials: TJ
authors.lastname: Openneer
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dietrich
authors.affiliation: Department of Cognitive Neuroscience, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Marcel P
authors.initials: MP
authors.lastname: Zwiers
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Psychiatry, Groningen, The Netherlands.
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Hoekstra
authors.affiliation: Department of Cognitive Neuroscience, Donders Institute of Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands; Karakter Child and Adolescent Psychiatry University Center, Nijmegen, The Netherlands.
authors.forename: Jan K
authors.initials: JK
authors.lastname: Buitelaar
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000378:metabolism*; D002648:Child; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D008297:Male; D017072:Neostriatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D005879:Tourette Syndrome / Q000000981:diagnostic imaging / Q000378:metabolism*
chemical_list: D018698:Glutamic Acid
keywords: ADHD; Fronto-striatal circuit; Glutamate; MRS; Tourette syndrome