Imaging the pre- and postsynaptic side of striatal dopaminergic synapses in idiopathic cervical dystonia: a SPECT study using [123I] epidepride and [123I] beta-CIT.
There is increasing evidence that a dysfunction of the dopaminergic system may be involved in the pathogenesis of idiopathic dystonia. To visualize possible alterations of the pre- and postsynaptic side of striatal dopaminergic synapses, SPECT studies using the radiotracers [123I] epidepride and [123I] beta-CIT were performed in 10 patients with idiopathic cervical dystonia. Eleven age- and sex-matched subjects served as controls. [123I] Epidepride is a new highly affine marker of D2 receptors, and [123I] beta-CIT binds to dopamine transporters on dopaminergic nerve endings. [123I] Epidepride binding was significantly reduced in both striata of dystonia patients compared with controls (p < 0.05). In contrast, striatal [123I beta-CIT uptake did not differ from controls. We conclude that dopaminergic dysfunction in idiopathic focal dystonia mainly involves postsynaptic mechanisms and suggest a disturbance of the indirect pathway of the motor circuit resulting in a disinhibited thalamocortical stimulation.
Naumann
M
M
Department of Neurology, Bayerische Julius-Maximilians-Universität Würzburg, Germany.
Pirker
W
W
Reiners
K
K
Lange
K W
KW
Becker
G
G
Brücke
T
T
D000328:Adult; D000368:Aged; D001549:Benzamides; D001931:Brain Mapping; D002352:Carrier Proteins / Q000502:physiology*; D003042:Cocaine / Q000031:analogs & derivatives*; D003287:Contrast Media; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D050483:Dopamine Plasma Membrane Transport Proteins; D004422:Dystonia Musculorum Deformans / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000503:physiopathology; D009419:Nerve Tissue Proteins; D011759:Pyrrolidines; D011954:Receptors, Dopamine / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon; D014103:Torticollis / Q000000981:diagnostic imaging* / Q000503:physiopathology
D001549:Benzamides; D002352:Carrier Proteins; D003287:Contrast Media; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011759:Pyrrolidines; D011954:Receptors, Dopamine; C063525:epidepride; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine