Quantitative analysis of striatal dopamine D2 receptors with 123 I-iodolisuride SPECT in degenerative extrapyramidal diseases.
123I-Iodolisuride has high specific affinity for binding on dopamine D2 receptors in the striatum and has been used in a few single photon emission computed tomography (SPECT) studies of extrapyramidal disorders. The diagnosis of Parkinson's disease (PD) is very difficult in the first 5 years of evolution, with 15-25% false positive diagnoses. The aim of this study was therefore to determine the value of iodolisuride SPECT in discriminating Parkinson's from the most frequent Parkinson-plus syndromes (PPS). Seventeen patients with an extrapyramidal syndrome had a SPECT examination 1 h after injection of 180-185 MBq of 123I-iodolisuride. They were followed under dopaminergic treatment for at least 2 years. After 2 years, they were separated in two groups according to specific clinical criteria and sensitivity to dopaminergic treatment: nine patients had PD (age = 59.8+/-8.8 years; Hoehn and Yahr = 1.8+/-0.7; evolution = 4.3+/-3 years) and eight had PPS (age = 71.6+/-7.3 years; Hoehn and Yahr = 2.9+/-2.0; evolution = 4.1+/-1.5 years). The binding potential of iodolisuride in the striatum was assessed by considering the striatum (S)/occipital lobe (O) ratio at the pseudo-equilibrium 1 h after injection. The S/O ratio was statistically different between PD and PPS (1.97+/-0.3 vs. 1.65+/-0.2 (P<0.02)). Iodolisuride SPECT could differentiate both groups with a sensitivity of 88.8% and a specificity of 75%. Iodolisuride is a good specific D2 receptor ligand for SPECT and complements specific clinical criteria for the diagnosis of Parkinson's disease and differentiation between different extrapyramidal disorders.
Prunier
C
C
Department of Nuclear Medicine and INSERM U316, University Hospital of Tours, France. c.prunier@bretonneau.chu-tours.fr
Tranquart
F
F
Cottier
J P
JP
Giraudeau
B
B
Chalon
S
S
Guilloteau
D
D
De Toffol
B
B
Chossat
F
F
Autret
A
A
Besnard
J C
JC
Baulieu
J L
JL
D000368:Aged; D000369:Aged, 80 and over; D001480:Basal Ganglia Diseases / Q000000981:diagnostic imaging*; D003342:Corpus Striatum / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics; D008090:Lisuride / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging*; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging; D017448:Receptors, Dopamine D2 / Q000032:analysis*; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging; D015899:Tomography, Emission-Computed, Single-Photon
D007457:Iodine Radioisotopes; D017448:Receptors, Dopamine D2; C075786:iodolisuride; D008090:Lisuride