[123I]-FP-CIT SPECT and olfaction test in patients with combined postural and rest tremor

• Published in: Journal of Neural Transmission 2008-03, Vol.115 (3), p.469-472
• Main Authors: Djaldetti, R., Nageris, B. I., Lorberboym, M., Treves, T. A., Melamed, E., Yaniv, E.
• Format: Article
• Language: English
• Subjects: Diagnosis, Differential; Diagnostic Tests, Routine; Essential Tremor - diagnosis; Humans; Medicine; Medicine & Public Health; Middle Aged; Neurology; Neurosciences; Parkinson Disease - diagnosis; Parkinson Disease - physiopathology; Psychiatry; Radiopharmaceuticals; Smell - physiology; Tomography, Emission-Computed, Single-Photon; Tremor - diagnosis; Tropanes
• ISSN: 0300-9564; 1435-1463
• DOI: 10.1007/s00702-007-0851-0

Mixed-type tremors pose a clinical diagnostic challenge. The aim of the study was to better characterize patients with combined postural and rest tremor. Patients were categorized into four groups: essential tremor (ET) ( n = 7), combined rest + postural tremor ( n = 17), PD ( n = 17), and control subjects ( n = 9). All underwent the University of Pennsylvania Smell Identification Test (UPSIT). The mixed-tremor group was also evaluated with SPECT imaging using the dopamine transporter (DaT) ligand 123 I-labeled FP-CIT. There was no significant difference in olfaction scores between the mixed tremor and essential tremor groups (23.2 ± 6.6 vs 21.7 ± 4.9) or between these groups and controls (27.2 ± 5.0). The patients with PD had significantly lower scores than all the other groups (13.7 ± 5.4, p < 0.001). Of the 12 patients with mixed tremor evaluated by SPECT, 9 had normal findings. This study suggests that rest tremor is part of the spectrum of ET, even in patients with long-standing disease. However, in a minority of patients, there might be transformation of ET–PD.