Imaging of D2 dopamine receptors of patients with Parkinson's disease using single photon emission computed tomography and iodobenzamide I 123
V. Laulumaa, J. T. Kuikka, H. Soininen, K. Bergstrom, E. Lansimies and P. Riekkinen
Department of Neurology, Kuopio University Hospital, Finland.
OBJECTIVE--To test the usefulness of single photon emission computed
tomography (SPECT) with iodobenzamide in imaging basal ganglia and to
elucidate the postulated upward regulation of the striatal D2 dopamine
receptors in patients with early Parkinson's disease. DESIGN--Fourteen
patients with Parkinson's disease and eight control subjects were
investigated with SPECT using iodobenzamide labeled with iodine 123 as
dopamine receptor ligand. SETTING--Neurological outpatient service at a
university hospital in Kuopio, Finland. PATIENTS--Fourteen patients with
recently diagnosed unilateral, unmedicated Parkinson's disease and eight
healthy control subjects. RESULTS--The SPECT images revealed high uptake of
iodobenzamide in the basal ganglia. In the patient group, the accumulation
was more intense and the iodobenzamide affinity rate was significantly
higher in the striatum contralateral to the parkinsonian symptoms. Also,
the basal ganglia-cerebellum ratio was higher in the contralateral
hemisphere. In the control group, no significant side-to-side differences
were observed. CONCLUSION--Iodobenzamide with SPECT imaging is useful in
evaluating patients with Parkinson's disease. The results also suggest
compensatory D2 dopamine receptor upward regulation in the striatum of
patients with early unmedicated Parkinson's disease.
