engleski

Accurate differentiation of Parkinson’s disease and essential tremor using quantitative assessment of brain SPECT with 123I-Ioflupane (DaTSCAN®)

Parkinson's disease (PD) is a chronic progressive neurodegenerative central nervous system (CNS) disease of unknown aetiology. The main biochemical disturbance of PD is hypofunction of dopaminergic nigrostriatal system in the basal ganglia. 123I-Ioflupane (DaTSCAN®) is a widely used radiopharmaceutical which consists of few cocaine derivates that selectively bind to the dopamine neurotransmitters (DAT). For the purpose of an adequate and early treatment of patients with PD, the possibility of precise and early differentiation of PD from essential tremor (ET), which is not characterized by the dopaminergic neuron, has been estimated using 123I-Ioflupane brain single photon emission computed tomography (SPECT) and combination of visual method and semiquantitative analysis of normalized activity ratio between striatum and occipital cortex. In the Clinical Institute of Nuclear Medicine and Radiation Protection the binding of DaTSCAN® (125-135 MBq) in 134 patients with clinically uncertain PD (58 male and 76 female, median 67, interquartile range 58-72 years) was investigated. Differentiation between PD and ET was based on visual interpretation and quantification of distribution of 123I-Ioflupane accumulation within regions of interest (ROI) of basal ganglia, nucleus caudatus and putamen (3-4 h p.i., 128x128 matrix, 64x30 s, 360°, LEHR parallel collimator, filtered back-projection). Results: Reduced striatal dopamine transmitters’ (DAT) density was detected in 64 PD patients. Normal distribution of presinaptic dopaminergic neurons in the striatum had 70 patients with ET. Normalized activity ratio between the striatum and occipital cortex in PD patients was 0.85 (0.44-1.3) and 2.44 (1.78-3.1) in ET patients. The accumulation of 123I-Ioflupane in patients with PD was significantly reduced compared to the ET patients (in the striatum p = 5.8x10-32, in putamen p = 1.7x10-36, in caudate of advanced PD stadium p = 1.3x10-27). In the striatum, putamen, and caudate (for all p < 10-17, nonparametric ANOVA) of the PD patients accumulation of 123I-Ioflupane is progressively reducing with the advancing of PD. 123I-Ioflupane brain SPECT is a reliable and sensitive biomarker of nigrostriatal neuronal integrity in vivo that is an important addition to the clinical practice, thus enabling an early introduction of neuroprotective therapy.

Parkinson's disease; essential tremor; 123I-Ioflupane

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