Striatal dopamine transporter imaging correlates with depressive symptoms and tower of London task performance in Parkinson's disease
ABSTRACT We studied whether the (123)I-FP-CIT uptake in the striatum correlates with depressive symptoms and cognitive performance in patients with Parkinson's disease (PD). Twenty patients with PD without major depression and/or dementia (mean age 61.7 +/- 12.7 years) underwent the (123)I-FP-CIT SPECT. Depressive symptoms and cognitive performance were assessed in the ON state. The ratios of striatal to occipital binding for the entire striatum, putamina, and putamen to the caudate (put/caud) index were calculated in the basal ganglia. The association between neuropsychiatric measures and dopamine transporter (DAT) availability was calculated; multiple regression analysis was used to assess association with age and disease duration. We found significant correlations between Montgomery and Asberg Depression Rating Scale (MARDS) and Tower of London (TOL) task scores and (123)I-FP-CIT uptake in various striatal ROIs. Multiple regression analysis confirmed the significant relationship between TOL performance and put/caud ratio (P = 0.001) and to age (P = 0.001), and between MADRS and left striatal (P = 0.005) and putaminal DAT availability (P = 0.003). Our pilot study results demonstrate that imaging with (123)I-FP-CIT SPECT appears to be sensitive for detecting dopaminergic deficit associated with mild depressive symptoms and specific cognitive dysfunction in patients with PD, yet without a current depressive episode and/or dementia.
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ABSTRACT: ABSTRACT Background: Depression is the most common psychiatric manifestation in patients with Parkinson's disease (PD). In addition, depressive symptoms may be considered to be a prodromal manifestation of PD. In recent years, the association between PD and depression has been the focus of neuroimaging studies using functional and structural techniques. Methods: The aim of this study was to review the main neuroimaging studies assessing the comorbidity between depression and PD. Literature searches were conducted to find the major neuroimaging studies that consider primarily the comorbidity between depression and PD using the indices Web of Science and Lilacs. Results: In total, 296 papers were identified, and 18 of these studies were selected for the current review. The principal neuroimaging technique used was SPECT. The structural neuroimaging studies that have evaluated the impact of current or previous bouts of depression on the neurodegenerative process of PD are scarce and inclusive. The instruments that were used to evaluate depression differed among the studies. Several brain regions appear to be involved in depression, particularly the limbic system and the basal ganglia. In addition, the serotonergic, dopaminergic, and noradrenergic systems also appear to be associated with depressive symptoms in PD. Conclusion: Several brain regions and neurotransmitter systems are involved in depression in PD; however, the variety of criteria used to evaluate depressive symptoms precludes more specific conclusions.International Psychogeriatrics 09/2013; 25(12):1-9. DOI:10.1017/S1041610213001427 · 1.89 Impact Factor
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ABSTRACT: In this work, a linear procedure to perform the intensity normalization of FP-CIT SPECT brain images is presented. This proposed methodology is based on the fact that the histogram of intensity values can be fitted accurately using a positive skewed α-stable distribution. Then, the predicted α-stable parameters and the location-scale property are used to linearly transform the intensity values in each voxel. This transformation is performed such that the new histograms in each image have a pre-specified α-stable distribution with desired location and dispersion values. The proposed methodology is compared with a similar approach assuming Gaussian distribution and the widely used specific-to-nonspecific ratio. In this work, we show that the linear normalization method using the α-stable distribution outperforms those existing methods.NeuroImage 10/2012; 65. DOI:10.1016/j.neuroimage.2012.10.005 · 6.13 Impact Factor
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ABSTRACT: BACKGROUND: Anxiety is a common non-motor symptom among patients with Parkinson's disease (PD). Although the etiology of anxiety in PD is likely to be multifactorial, a dysfunction in the dopaminergic system might be implicated in its pathogenesis. The aim of our study was to investigate a possible dopaminergic mechanism involved in anxiety in newly diagnosed never-medicated PD patients using SPECT and (123)I-FP-CIT as the dopamine transporter ligand. METHODS: Thirty-four newly diagnosed, untreated PD patients with asymmetric motor symptoms were included in the study: 17 patients with right- and 17 with left-motor onset, matched for age, disease duration and motor disability constituted the group. They were all evaluated for anxiety and depression and underwent an SPECT with (123)I-FP-CIT. Dopamine transporter (DAT) availability values for right and left caudate and putamen were calculated and compared between patients with and without anxiety. Regression analyses were also performed in order to correlate DAT availability with the severity of the anxiety symptoms. RESULTS: Comparison between PD patients with and those without anxiety revealed significant differences of DAT availability in all the examined regions except the right putamen. In the group of patients considered as a whole, a significant correlation was found between increased anxiety severity and decreased DAT availability in right caudate. CONCLUSIONS: We reported an association between nigrostriatal DAT availability deficits and anxiety symptoms in newly diagnosed, untreated PD patients. Our results suggest that hypofunction of the nigrostriatal dopaminergic system may represent one of the functional anomalies involved in anxiety in PD from the earliest stages of disease and irrespective of any therapy.Parkinsonism & Related Disorders 07/2012; 18(9). DOI:10.1016/j.parkreldis.2012.05.022 · 4.13 Impact Factor