123I-FP-CIT SPECT imaging of dopamine transporters in patients with cerebrovascular disease and clinical diagnosis of vascular parkinsonism.
The purpose of our study was to prospectively evaluate the striatal uptake of 123I-labeled N-(3-fluoropropyl)-2beta-carbomethoxy-3beta-(4-iodophenyl)nortropane (FP-CIT) and the response to l-dopa therapy in patients with cerebrovascular disease (CVD) who develop clinical symptoms of vascular parkinsonism (VP).


METHODS
Twenty consecutive patients who developed VP in the course of CVD were prospectively enrolled in the study. All patients had CT evidence of CVD (17 patients had lacunar infarcts, 3 patients had territorial strokes). The clinical stage of the patients was assessed using the Hoehn and Yahr scale, and the severity of the symptoms was measured using the Unified Parkinson's Disease Rating Scale score. Ten age-matched subjects were used as controls. SPECT was performed 180 min after injection of 185 MBq 123I-FP-CIT using a dual-head gamma-camera. The ratio of the mean specific-to-nonspecific striatal binding for the entire striatum, caudate, and putamen was calculated in all patients and compared with that of controls. Putamen-to-caudate binding ratios were compared as well. The response to therapy was compared between patients with normal and abnormal 123I-FP-CIT binding.


RESULTS
No correlation was found between any of the clinical variables and response to therapy in patients with VP. Nine patients had normal striatal 123I-FP-CIT binding with no significant differences in striatal or subregional binding ratios compared with those of the controls. In contrast, 11 patients had significantly diminished striatal binding compared with that of controls (P < 0.001). Subanalyses showed significantly decreased binding in the caudate (P < 0.04 and P < 0.01 for the right and left caudate, respectively), diminished binding in the putamen (P < 0.04 and P < 0.01 for the right and left putamen, respectively), and a decreased putamen-to-caudate ratio on the right side (P < 0.001). The latter ratio was not significant on the left. Two of the 3 patients with territorial strokes had significantly diminished striatal 123I-FP-CIT binding in the hemisphere contralateral to the CT lesion. All 9 patients with normal scan findings had a poor response to L-dopa. Six of 11 patients with abnormal studies had no response to L-dopa, whereas 5 patients had a good response (P < 0.03).


CONCLUSIONS
The diagnosis of VP cannot be accurately confirmed on the basis of clinical features alone because CVD may alter the typical presentation of PD. Functional imaging with 123I-FP-CIT is highly recommended in patients with CVD who develop symptoms of VP to confirm or exclude the existence of nigrostriatal dopaminergic degeneration. Identifying a subset of patients with reduced 123I-FP-CIT binding in the striatum is important for better treatment selection.
Department of Nuclear Medicine, Edith Wolfson Medical Center, Holon, Israel. mvlorber@zahav.net.il
Mordechai
M
Lorberboym
Ruth
R
Djaldetti
Eldad
E
Melamed
Menahem
M
Sadeh
Yair
Y
Lampl
D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents / Q000627:therapeutic use; D002561:Cerebrovascular Disorders / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009942:Organometallic Compounds / Q000493:pharmacokinetics; D010302:Parkinson Disease, Secondary / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
C470087:(12-cyano-12,13-dihydro-11H-cyclopentadipyrido(b-3,2-h, 2',3'-j)phenazine-12-carboxylic acid methyl ester)bis(1,10-phenanthroline)ruthenium(II); D000978:Antiparkinson Agents; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D007980:Levodopa