Nurit Birman, Mordechai Lorberboym, Yair Lampl and Ruth Djaldetti
Objective: The gold standard for diagnosis of Parkinson's disease (PD) is SPECT with dopamine transporters (DaT). Reduced ligand uptake in the dorsal putamen is usually more prominent in the hemisphere contralateral to the side with more predominant clinical symptoms. However, in some cases, loss of ligand uptake is more severe on the ipsilateral side. The aim of the study was to characterize the clinical symptoms and outcome of patients with an initial diagnosis of PD and SPECT findings of reduced ligand uptake on the side ipsilateral to the motor symptoms.
Methods: All SPECT studies performed at Wolfson Medical Center in 2001-2013 were reviewed for findings of an asymmetrical striatal decrease in ligand uptake. The side with the greater loss in uptake was recorded, and data on the side of disease onset were retrieved from the medical files of the corresponding patients. Patients with mismatched findings formed the study group and were further evaluated for clinical characteristics and disease course.
Results: Of the 95 patients with asymmetric DaT binding on SPECT whose medical files were available for analysis, 11 met the inclusion criteria. On long-term follow-up (2-13 years), 5 had a typical course of PD. Among the remainder, one had possible diffuse Lewy body disease, one had vascular Parkinsonism, and 4 had nonprogressive disease.
Conclusion: Loss of DaT binding ipsilateral to the clinically more affected side should raise suspicions of a diagnosis other than PD.