title: Topography of cerebral monoamine transporter availability in families with SCA2 mutations: a voxel-wise [123I]beta-CIT SPECT analysis.
abstract: OBJECTIVE
  The purpose of this study was to investigate the monoamine transporter status of dopamine, serotonin and norepinephrine throughout the brain in spinocerebellar ataxia type 2 (SCA2). To this end, nine patients were studied with [(123)I]beta-CIT SPECT.
  
  
  METHODS
  Data were compared with ten age-matched healthy control subjects and ten patients with young-onset Parkinson's disease (YOPD), matched for age. Parametric SPECT images of the specific-to-non-displaceable equilibrium partition coefficient (V (3)''), which is proportional to the receptor density (B (max)), were generated. In order to objectively localise focal changes in beta-CIT uptake throughout the brain volume without having to make an a priori hypothesis as to their location, statistical parametric mapping (SPM) was applied to SPECT images. Data clusters revealed by SPM, showing significant differences in V (3)'' values between groups, were transformed onto the individual V (3)'' image to obtain mean regional uptake values.
  
  
  RESULTS
  Both SCA2 and YOPD patients showed significant decreases in striatal [(123)I]beta-CIT SPECT uptake when compared with controls. However, in SCA2 patients, additional reductions in caudate/anterior putamen, midbrain and pons [(123)I]beta-CIT uptake were localised with SPM.
  
  
  CONCLUSIONS
  Voxel-wise analysis of [(123)I]beta-CIT SPECT revealed more widespread decline of monoamine transporter availability in SCA2 than in YOPD, reflecting differences in the underlying pathology. We suggest that the quantification of midbrain and pons [(123)I]beta-CIT signal is likely to improve the diagnostic accuracy in patients presenting with clinical features of both SCA2 and YOPD at initial investigation.
authors.affiliation: Department of Neurology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria. christoph.scherfler@uibk.ac.at
authors.forename: Christoph
authors.initials: C
authors.lastname: Scherfler
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Boesch
authors.forename: Eveline
authors.initials: E
authors.lastname: Donnemiller
authors.forename: Klaus
authors.initials: K
authors.lastname: Seppi
authors.forename: Helga
authors.initials: H
authors.lastname: Weirich-Schwaiger
authors.forename: Georg
authors.initials: G
authors.lastname: Goebel
authors.forename: Irene
authors.initials: I
authors.lastname: Virgolini
authors.forename: Gregor K
authors.initials: GK
authors.lastname: Wenning
authors.forename: Werner
authors.initials: W
authors.lastname: Poewe
mesh_terms: D000328:Adult; D000067528:Ataxins; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D016022:Case-Control Studies; D003042:Cocaine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D019275:Radiopharmaceuticals; D020754:Spinocerebellar Ataxias / Q000000981:diagnostic imaging* / Q000235:genetics / Q000378:metabolism*; D015899:Tomography, Emission-Computed, Single-Photon; D050493:Vesicular Monoamine Transport Proteins / Q000378:metabolism*
chemical_list: D000067528:Ataxins; D007457:Iodine Radioisotopes; D009419:Nerve Tissue Proteins; D019275:Radiopharmaceuticals; D050493:Vesicular Monoamine Transport Proteins; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine