Single photon emission computed tomographic imaging demonstrates loss of striatal dopamine transporters in Parkinson disease.
[123I][(1R)-2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane] ([123I]beta-CIT) labels dopamine transporters and is, therefore, a marker of neurons that degenerate in Parkinson disease. Single photon emission computed tomography imaging with [123I]beta-CIT showed that radioactivity in striatal regions in healthy subjects increased during a 2-day imaging study, whereas that in Parkinsonian patients peaked earlier at reduced levels relative to healthy subjects. Kinetic analyses of radioactivity in plasma and brain suggest that this decrease was due to an approximately 65% loss of target sites in patients compared with healthy subjects; greater losses occurred in putamen than in caudate. All patients showed lateralized differences in striatal uptake, with greater losses in the striatum contralateral to the side of the body with initial symptoms. These preliminary results suggest that [123I]beta-CIT is a marker for the loss of striatal dopamine terminals in patients with Parkinson disease. Single photon emission computed tomographic imaging with [123I]beta-CIT may be useful for early diagnosis of the disorder, for monitoring the progression of the disease, and for distinguishing the idiopathic disorder from other Parkinsonian syndromes with more widespread pathology.
Innis
R B
RB
Department of Psychiatry, Yale University School of Medicine, West Haven, CT 06510.
Seibyl
J P
JP
Scanley
B E
BE
Laruelle
M
M
Abi-Dargham
A
A
Wallace
E
E
Baldwin
R M
RM
Zea-Ponce
Y
Y
Zoghbi
S
S
Wang
S
S
D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism*; D003042:Cocaine / Q000031:analogs & derivatives / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000378:metabolism*; D012016:Reference Values; D015899:Tomography, Emission-Computed, Single-Photon
D000978:Antiparkinson Agents; D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D007980:Levodopa; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine; D004298:Dopamine