[Initial experiences with 123-Iodine-IBZM neuroreceptor scintigraphy in extrapyramidal disorders]

The receptor scintigraphy of the dopaminergic system of the brain is of interest in the evaluation of movement disorders. The 123I-IBZM is a radiopharmaceutical with affinity predominantly to postsynaptic D2 receptors. The aim of this study was to evaluate the role of IBZM SPECT investigations in the differentiation of disorders with Parkinson's syndrome. Eight patients with idiopathic Parkinson's syndrome and 8 patients Parkinson's syndrome with other etiology were investigated with 123I-IBZM SPECT (6 females, 10 males, mean age +/- SD: 59 +/- 9). The patients according to the clinical signs and symptoms, results of CT/MRI and rCBF SPECT investigation were categorized. The reconstructed SPECT slices were evaluated visually and quantitatively. The visual interpretation of the images were performed by two observer and scored the radiopharmaceutical uptake (from 1-3) of the cortex and the striatum separately. For quantification striatum/frontal cortex activity ratio were calculated with ROI technique. The differences between the patient groups were statistically analyzed by two tailed t-test. The IBZM uptake were different in the two group of patients. The striatal IBZM accumulation was higher in the idiopathic Parkinson's syndrome patients compared to the other parkinsonians. The striatum/frontal lobe activity ratio was 1.69 +/- 0.9 (mean +/- SD) in the right, 1.67 +/- 0.04 (mean +/- SD) in the left hemisphere of the patients with idiopathic Parkinson's syndrome. The corresponding data in the nonidiopathic parkinsonian group were 1.53 +/- 0.06 (mean +/- SD), 1.52 +/- 0.04 (mean +/- SD) respectively (p < 0.01). The quantitative data correlated with the results of the visual evaluation. According to the data presented IBZM-SPECT is an effective tool in the differentiation of disorders with Parkinson syndrome.