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Parkinson's disease (PD) is a complex, heterogeneous neurodegenerative disorder, affecting approximately 1% of the population over 60 years of age. The molecular and cellular mechanisms underlying PD pathogenesis are still unknown. Clathrin-mediated endocytosis (CME) is a procedure closely related to the intracellular trafficking of multiple molecules in the cell, including proteins, lipids, and neurotransmitters. Recently, variations in the gene encoding the phosphatidylinositol binding clathrin assembly protein (PICALM) has been associated with Alzheimer's disease (AD), suggesting a possible role of CME in the pathogenesis of neurodegenerative diseases. In this study, we examined for the first time the potential role of the PICALM rs3851179 polymorphism in PD. We studied the PICALM rs3851179 polymorphism in 191 Greek patients with sporadic PD and 118 control subjects, using a PCR-RFLP method. Our results do not provide evidence that the PICALM rs3851179 polymorphism increase susceptibility of PD, in the Greek population. [ABSTRACT FROM AUTHOR]

The purpose of this study was the evaluation of pupil light reflex (PLR) in patients with Parkinson's disease (PD) by using a modern pupillometry system and the investigation of its potential relationship with dopamine transporter imaging (DaTSCAN), which is an objective method for the evaluation of presynaptic dopaminergic system. PLR was evaluated using pupillometry in 35 patients with PD without clinical evidence of autonomic dysfunction and 44 healthy matched controls. PLR was elicited using a fully automated pupillometry system and six parameters were measured. Dopamine transporter imaging was performed using radioactive ioflupane 123I-FP-CIT [[123I-N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)-nortropane]]. A significant increase in latency and a significant decrease in amplitude, maximum constriction velocity, as well as maximum acceleration were observed in PD patients. There was no significant difference in initial radius and minimum radius values. Investigating the relationship between pupillometry parameters and 123I-FP-CIT binding values, we correlated values from the semiquantitative analysis of radioligand uptake with pupillometry parameters, but we found no significant correlation. This study demonstrates PLR impairment in patients with PD without overt autonomic dysfunction. This impairment does not seem to correspond to the reduction of radioligand binding in the striatum as the result of presynaptic dopaminergic dysfunction, suggesting a different deterioration rate of these systems. [ABSTRACT FROM AUTHOR]

Background: Recent studies revealed that aphasic speakers have difficulties with the production of the intransitive (unaccusative) variant of verbs entering transitivity alternations. A key point of the current interpretations of these difficulties concerns the movement operations taking place at surface syntax, namely, the A-movement operation (Bastiaanse & van Zonneveld, 2005; Bastiaanse, 2008; Thompson, 2003). Aim: The present study revisits the issue of processing verbs with alternating transitivity in non-fluent aphasia in Greek, a language with rich morphology and relatively free word order, which lacks A-movement. In addition, in Greek, unaccusative verbs appear with different voice morphology: One class of intransitive variants of alternating verbs bears active morphology, another one non-active morphology and a third one can surface with both. The presence of non-active voice has been argued to correspond to the presence of a voice projection in syntax of these variants, while the variants that bear active morphology are not associated with a voice projection at the level of syntax. This study investigates the ability of non-fluent aphasic speakers to produce and comprehend verbs entering transitivity alterations and explores the role of active vs. non-active morphology and word order in the performance of aphasic speakers. Methods & Procedures: We tested five non-fluent patients and fifteen control participants. We used two tasks supported by pictures: an elicited production task and a comprehension task. The experimental material consisted of fifteen transitive and fifteen unaccusative verbs (marked for active, and/or non-active voice morphology) in sentence contexts. Outcomes & Results: The results indicated that (i) the aphasic speakers performed better on the production and comprehension of transitives than of unaccusatives, (ii) they showed significantly lower performance on the comprehension of unaccusatives with active morphology than on unaccusatives with non-active morphology, and finally (iii) they produced transitive (S)VO structures instead of the unaccusative ones. Conclusion: We suggest, in agreement with other researchers (for example, Schwartz, Linebarger, Saffran, & Pate, 1987) that aphasic individuals overuse a mapping strategy that associates the theta roles of agent and theme with syntactic subject and object respectively, as they produce transitive (S)VO structures, to a large extent, instead of unaccusatives. In addition, as they had difficulties with unaccusative verbs marked for active voice, we suggest that they could not successfully interpret unaccusative verbs with active voice morphology as non-agentive structures. [ABSTRACT FROM AUTHOR]

We evaluated pupil light reflex (PLR) in patients with Parkinson's disease (PD) and normal controls by means of pupillometry and explored its possible relation to clinical characteristics in parkinsonian patients. PLR was evaluated using pupillometry in 66 patients with PD without clinical evidence of autonomic dysfunction and 44 healthy matched controls. PLR was elicited by single flash stimuli of 24.6 candelas/m2 intensity and 20 ms duration, and six parameters were studied after full recording of pupil's movement. A significant increase in latency (T1) and significant decrease in amplitude (R1-R2), maximum constriction velocity (Vmax), as well as maximum acceleration (ACmax) was found in parkinsonian patients. There was no significant difference in initial radius (R1) and minimum radius (R2) values. Of the parameters studied, ACmax emerged as a significant predictor for discrimination between PD patients and controls. There was no significant correlation between pupillometry parameters and clinical characteristic of patients (disease duration, stage, and the Unified Parkinson's Disease Rating motor scale). The study demonstrates PLR disorder in PD patients even without overt clinical autonomic dysfunction. Pupillometry appears to be a useful and noninvasive method for exploration of PLR alterations in PD and may prove to be useful for the early detection of subclinical autonomic nervous system dysfunction. [ABSTRACT FROM AUTHOR]

A translated version of the Mattis Dementia Rating Scale (DRS) into Greek ((DRS-GR) was applied to a sample of Greek population (N = 356) comprising normal middle-aged and elderly subjects (controls), as well as patients suffering from Parkinson's (PD) and Alzheimer's disease (AD) to test its reliability and validity. A well-known dementia screening instrument, the Mini Mental State Examination test (MMSE), and a nonverbal measure of abstract reasoning, the Raven Coloured Progressive Matrices, were employed as measures of DRS-GR concurrent validity. Reliability analysis was satisfactory with Cronbach's alpha reaching 0.82 and item to total correlations yielding high coefficients for most items. DRS-GR scores were influenced by age and education, but not by gender. Correlation between MMSE and the total DRS-GR score was significant in patients and normal controls, but correlation between DRS-GR and RCPM was significant in AD and nondemented PD only. Specificity and sensitivity for dementia screening, calculated on a Receiver Operating Characteristic curve, with a cut-off score the mean value minus two standard deviations, corrected for age and education, was 96% and 80%, respectively. Our preliminary findings show that DRS-GR is a reliable and well-adapted instrument for clinical application in the Greek population. [ABSTRACT FROM AUTHOR]