Browsing by Author "Kostic, Vladimir (57189017751)"

[No abstract available]

[No abstract available]

Symptoms of Parkinson’s disease (PD) progress over time causing significant disability. Yet, change in disability over shorter time periods has not been entirely understood. The purpose of this study was to assess the Self-Assessment Disability Scale (SADS) in persons with Parkinson’s disease (PD) after 2 years of follow-up and compare it with the score observed at baseline. Additionally, we aimed at evaluating association of motor and non-motor PD features at baseline with a higher disability after 2 years of follow-up. A total of 120 consecutive persons with PD, who denied falling in the past 6 months, were initially recruited. After 2 years of follow-up, 88 (73.3%) persons with PD were evaluated for SADS. The total disability (SADS) score did not change after follow-up (p = 0.529). We observed increase in difficulty at “Getting out of bed” (p = 0.006), “Getting up out of armchair” (p = 0.013), “Walking about house/flat” (p = 0.003), “Walking outside” (p = 0.010), and “Traveling by public transport” (p = 0.014). After adjusting for several potential confounding factors, falls in the past year (β = 8.32, 95% confidence interval (CI) 1.04–15.59) and higher Unified Parkinson’s Disease Rating Scale part 3 at baseline (β = 0.26, 95%CI 0.01–0.51) remained associated with higher PD-related disability. This finding suggests that accumulation of overall PD-related disability tends to occur over a longer time span. Further studies are needed to gradually assess long-term evolution of disability in PD. © 2017, Springer-Verlag Italia.

[No abstract available]

[No abstract available]

Objective: To determine frequency and type of cognitive disorders in cross-sectional analysis of a Parkinson’s disease (PD) cohort, and explore its relations to motor symptoms, modifiable vascular risk factors and white matter lesions (WML) volume. Methods: In a group of 133 PD patients, mild cognitive impairment (PD-MCI) and dementia (PDD) were diagnosed according to Movement Disorders Society Task Force criteria (level 2 for PD-MCI). Detailed motor measurements were applied, including rigidity, axial, bradykinesia, tremor and postural instability gait disorders (PIGD) scores. Vascular risk was estimated by the Framingham General Cardiovascular Disease risk scoring algorithm and WML volume was measured for whole brain and frontal lobe. Results: Sixty-one (46.9%) patients fulfilled criteria for PD-MCI, and 23 (17.7%) for PDD. Non-amnestic multiple domain MCI was most frequent (52% of PD-MCI patients). Motor scores were significantly higher in cognitively impaired patients, but only axial score discriminated between MCI and dementia. High vascular risk was related to impaired cognition, bradykinesia, axial, PIGD and freezing of gait (FOG) score, while whole brain WML volume was associated with PDD, FOG and attention deficits. Furthermore, high vascular risk was identified as a potential predictor of both MCI and dementia in PD. Additionally, age and bradykinesia score were independently associated with PD-MCI and age, axial score and whole brain WML volume with PDD. Conclusion: Cognitive disorders in PD are associated with more severe, predominantly axial motor deficits and increased, but partly modifiable vascular burden, thus opening a possibility for development of preventive strategies in PD. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Objective: To determine frequency and type of cognitive disorders in cross-sectional analysis of a Parkinson’s disease (PD) cohort, and explore its relations to motor symptoms, modifiable vascular risk factors and white matter lesions (WML) volume. Methods: In a group of 133 PD patients, mild cognitive impairment (PD-MCI) and dementia (PDD) were diagnosed according to Movement Disorders Society Task Force criteria (level 2 for PD-MCI). Detailed motor measurements were applied, including rigidity, axial, bradykinesia, tremor and postural instability gait disorders (PIGD) scores. Vascular risk was estimated by the Framingham General Cardiovascular Disease risk scoring algorithm and WML volume was measured for whole brain and frontal lobe. Results: Sixty-one (46.9%) patients fulfilled criteria for PD-MCI, and 23 (17.7%) for PDD. Non-amnestic multiple domain MCI was most frequent (52% of PD-MCI patients). Motor scores were significantly higher in cognitively impaired patients, but only axial score discriminated between MCI and dementia. High vascular risk was related to impaired cognition, bradykinesia, axial, PIGD and freezing of gait (FOG) score, while whole brain WML volume was associated with PDD, FOG and attention deficits. Furthermore, high vascular risk was identified as a potential predictor of both MCI and dementia in PD. Additionally, age and bradykinesia score were independently associated with PD-MCI and age, axial score and whole brain WML volume with PDD. Conclusion: Cognitive disorders in PD are associated with more severe, predominantly axial motor deficits and increased, but partly modifiable vascular burden, thus opening a possibility for development of preventive strategies in PD. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.

Background Gait pattern is frequently impaired in multiple sclerosis (MS), however gait characteristics in patients with different MS phenotypes have not been fully elucidated. Methods We analyzed spatio-temporal gait pattern characteristics in patients with relapsing-remitting (RR, n=52) and primary-progressive (PP, n=18) MS in comparison with age-matched healthy controls (HC, n=40). All subjects performed a standardized simple walking task, a dual motor- motor task, a dual motor-mental task, and a triple combined motor-mental task at a GAITRite electronic walkway of 5.5 m active area. We measured: cycle time (CT), stride length (SL), swing time (ST), double support time (DST), gait velocity (GV) and calculated symmetry index (SI) for CT, SL and ST. Results With each task performed, CT and DST in the total MS group were significantly longer while SL was significantly shorter and GV significantly lower than in HC. ST was similar in the total MS patient group and HC. In both MS patients and HC, CT and DST increased and SL and GV decreased over repeated assessments. Dual and triple tasks while walking influenced walking performance in both MS patients and HC. Although patients with PPMS differed significantly from those with RRMS in the majority of gait parameters, the subgroup analysis in patients matched for age and disability (Expanded Disability Status Scale Score -EDSS, 3.0–5.0) showed similar gait performance in RRMS and PPMS patients having the same level of disability, except for CT and ST- symmetry parameters that were more impaired in the PPMS group. The EDSS score correlated significantly with CT, DST, SL and GV, but no significant correlation was found with ST except at the triple combined motor-mental task. Conclusion A disturbed gait pattern in MS patients with different MS phenotypes depends on disability and reflects a cognitive-motor interference. © 2017 Elsevier B.V.

Background Gait pattern is frequently impaired in multiple sclerosis (MS), however gait characteristics in patients with different MS phenotypes have not been fully elucidated. Methods We analyzed spatio-temporal gait pattern characteristics in patients with relapsing-remitting (RR, n=52) and primary-progressive (PP, n=18) MS in comparison with age-matched healthy controls (HC, n=40). All subjects performed a standardized simple walking task, a dual motor- motor task, a dual motor-mental task, and a triple combined motor-mental task at a GAITRite electronic walkway of 5.5 m active area. We measured: cycle time (CT), stride length (SL), swing time (ST), double support time (DST), gait velocity (GV) and calculated symmetry index (SI) for CT, SL and ST. Results With each task performed, CT and DST in the total MS group were significantly longer while SL was significantly shorter and GV significantly lower than in HC. ST was similar in the total MS patient group and HC. In both MS patients and HC, CT and DST increased and SL and GV decreased over repeated assessments. Dual and triple tasks while walking influenced walking performance in both MS patients and HC. Although patients with PPMS differed significantly from those with RRMS in the majority of gait parameters, the subgroup analysis in patients matched for age and disability (Expanded Disability Status Scale Score -EDSS, 3.0–5.0) showed similar gait performance in RRMS and PPMS patients having the same level of disability, except for CT and ST- symmetry parameters that were more impaired in the PPMS group. The EDSS score correlated significantly with CT, DST, SL and GV, but no significant correlation was found with ST except at the triple combined motor-mental task. Conclusion A disturbed gait pattern in MS patients with different MS phenotypes depends on disability and reflects a cognitive-motor interference. © 2017 Elsevier B.V.

The Leber's hereditary optic neuropathy (LHON) is a rare disease caused by mitochondrial DNA (mtDNA) mutations. Beside primary mutations, the effect of secondary mtDNA mutations in still unclear. We examined the effect of secondary mtDNA mutations on secondary structure of different mitochondrial RNAs. Whole mitochondrial genome sequence of LHON patients has been obtained from in six non related pedigrees by Sanger sequencing method. The effect of mutations located in mitochondrial RNA genes was examined by creating in silico models of RNA secondary and regional 3D structure, accompanied by sequence conservation analysis. All three primary LHON mutations (m.3460G>A, m.11778G>A and m.14484 T>C) were revealed in study families. Four mutations in MT-RNR1 gene (m.750A>G, m.956delC, m.1438A>G and m.1555A>G) were identified and only an m.1555A>G causes significant changes of secondary structure of mitochondrial 12S ribosomal RNA (rRNA), while it is the only mutation which does not alter its 3D structure. Five mutations (m.1811A>G, m.2706A>G, m.2831G>A, m.3010G>A and m.3197T>C) were discovered in MT-RNR2 gene and all of them induced substantial alterations of mitochondrial 16S rRNA secondary structure. Significant changes of mitochondrial 16S rRNA 3D structure are caused by m.1811A>G, m.2706A>G, m.3010G>A and m.3197T>C. A single insertion variant (m.15986insG) has been found in the MT-TP gene which encodes mitochondrial transfer RNA for Proline (tRNA Pro). This mutation does not cause substantial changes of tRNA for Proline secondary structure, while the 3D geometry remains without major changes. Most of the mutation loci exhibited high level of sequence conservation. Presence of multiple mutations in a single family appears to cause more extensive changes in mitochondrial 12S and 16S rRNA, then their individual influence. The effect of discovered mutations on in silico modelled RNA structure is in a significant correlation with the present knowledge about the potential of these mutation to participate in the pathophysiology of LHON and other human diseases. The presence of certain multiple mitochondrial RNA mutations could be a possible explanation of LHON clinical presentation in some families. All revealed mutations have been evaluated for the first time in terms of in silico structural modelling. The application of bioinformatics tools such as secondary and 3D RNA structure prediction can have a great advantage in better understanding of the molecular standpoint of the LHON pathophysiology and clinical phenotype. © 2020 Elsevier Ltd

The Leber's hereditary optic neuropathy (LHON) is a rare disease caused by mitochondrial DNA (mtDNA) mutations. Beside primary mutations, the effect of secondary mtDNA mutations in still unclear. We examined the effect of secondary mtDNA mutations on secondary structure of different mitochondrial RNAs. Whole mitochondrial genome sequence of LHON patients has been obtained from in six non related pedigrees by Sanger sequencing method. The effect of mutations located in mitochondrial RNA genes was examined by creating in silico models of RNA secondary and regional 3D structure, accompanied by sequence conservation analysis. All three primary LHON mutations (m.3460G>A, m.11778G>A and m.14484 T>C) were revealed in study families. Four mutations in MT-RNR1 gene (m.750A>G, m.956delC, m.1438A>G and m.1555A>G) were identified and only an m.1555A>G causes significant changes of secondary structure of mitochondrial 12S ribosomal RNA (rRNA), while it is the only mutation which does not alter its 3D structure. Five mutations (m.1811A>G, m.2706A>G, m.2831G>A, m.3010G>A and m.3197T>C) were discovered in MT-RNR2 gene and all of them induced substantial alterations of mitochondrial 16S rRNA secondary structure. Significant changes of mitochondrial 16S rRNA 3D structure are caused by m.1811A>G, m.2706A>G, m.3010G>A and m.3197T>C. A single insertion variant (m.15986insG) has been found in the MT-TP gene which encodes mitochondrial transfer RNA for Proline (tRNA Pro). This mutation does not cause substantial changes of tRNA for Proline secondary structure, while the 3D geometry remains without major changes. Most of the mutation loci exhibited high level of sequence conservation. Presence of multiple mutations in a single family appears to cause more extensive changes in mitochondrial 12S and 16S rRNA, then their individual influence. The effect of discovered mutations on in silico modelled RNA structure is in a significant correlation with the present knowledge about the potential of these mutation to participate in the pathophysiology of LHON and other human diseases. The presence of certain multiple mitochondrial RNA mutations could be a possible explanation of LHON clinical presentation in some families. All revealed mutations have been evaluated for the first time in terms of in silico structural modelling. The application of bioinformatics tools such as secondary and 3D RNA structure prediction can have a great advantage in better understanding of the molecular standpoint of the LHON pathophysiology and clinical phenotype. © 2020 Elsevier Ltd

Objective In this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution. Methods EEG signals from Cz and its surrounding channels were recorded during three sets of ankle dorsiflexion movements. Each set was interspersed with either a complex or a simple auditory oddball task for healthy participants and a complex auditory oddball task for stroke patients. Results The amplitude of the movement-related cortical potentials (MRCPs) decreased with the complex oddball paradigm, while MRCP variability increased. Both oddball paradigms increased the detection latency significantly (p < 0.05) and the complex paradigm decreased the true positive rate (TPR) (p = 0.04). In patients, the negativity of the MRCP decreased while pre-phase variability increased, and the detection latency and accuracy deteriorated with attention diversion. Conclusion Attention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method. Significance Brain–computer interfaces for neuromodulation that use the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz. © 2016 International Federation of Clinical Neurophysiology

Objective In this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution. Methods EEG signals from Cz and its surrounding channels were recorded during three sets of ankle dorsiflexion movements. Each set was interspersed with either a complex or a simple auditory oddball task for healthy participants and a complex auditory oddball task for stroke patients. Results The amplitude of the movement-related cortical potentials (MRCPs) decreased with the complex oddball paradigm, while MRCP variability increased. Both oddball paradigms increased the detection latency significantly (p < 0.05) and the complex paradigm decreased the true positive rate (TPR) (p = 0.04). In patients, the negativity of the MRCP decreased while pre-phase variability increased, and the detection latency and accuracy deteriorated with attention diversion. Conclusion Attention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method. Significance Brain–computer interfaces for neuromodulation that use the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz. © 2016 International Federation of Clinical Neurophysiology

The system of assigning locus symbols to specify chromosomal regions that are associated with a familial disorder has a number of problems when used as a reference list of genetically determined disorders,including (I) erroneously assigned loci, (II) duplicated loci, (III) missing symbols or loci, (IV) unconfirmed loci and genes, (V) a combination of causative genes and risk factor genes in the same list, and (VI) discordance between phenotype and list assignment. In this article, we report on the recommendations of the International Parkinson and Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders and present a system for naming genetically determined movement disorders that addresses these problems. We demonstrate how the system would be applied to currently known genetically determined parkinsonism, dystonia, dominantly inherited ataxia, spastic paraparesis, chorea, paroxysmal movement disorders, neurodegeneration with brain iron accumulation, and primary familial brain calcifications. This system provides a resource for clinicians and researchers that, unlike the previous system, can be considered an accurate and criterion-based list of confirmed genetically determined movement disorders at the time it was last updated. © 2016 International Parkinson and Movement Disorder Society.

The system of assigning locus symbols to specify chromosomal regions that are associated with a familial disorder has a number of problems when used as a reference list of genetically determined disorders,including (I) erroneously assigned loci, (II) duplicated loci, (III) missing symbols or loci, (IV) unconfirmed loci and genes, (V) a combination of causative genes and risk factor genes in the same list, and (VI) discordance between phenotype and list assignment. In this article, we report on the recommendations of the International Parkinson and Movement Disorder Society Task Force for Nomenclature of Genetic Movement Disorders and present a system for naming genetically determined movement disorders that addresses these problems. We demonstrate how the system would be applied to currently known genetically determined parkinsonism, dystonia, dominantly inherited ataxia, spastic paraparesis, chorea, paroxysmal movement disorders, neurodegeneration with brain iron accumulation, and primary familial brain calcifications. This system provides a resource for clinicians and researchers that, unlike the previous system, can be considered an accurate and criterion-based list of confirmed genetically determined movement disorders at the time it was last updated. © 2016 International Parkinson and Movement Disorder Society.

[No abstract available]

[No abstract available]

Background: Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia (EOD), characterized by behavioral changes (behavioral variant; bvFTD) or language deficits. A hexanucleotide repeat expansion in a noncoding region of chromosome 9 open reading frame 72 (C9orf72) has been proved to be a major cause of both familial and sporadic amyotrophic lateral sclerosis or FTD, with or without concomitant motor neuron disease (MND). Methods: The aim of this study was to assess the frequency of the C9orf72 hexanucleotide expansion in a cohort of 117 Serbian patients with EOD and to report phenotypic features of identified carriers. Results: We identified 4 of 117 (3.4%) patients with EOD to have C9orf72 hexanucleotide expansions. All patients were classified in the FTD disease spectrum group (8.2%): 3 patients fulfilled the criteria for bvFTD, and 1 patient had FTD-MND. None of the patients with the C9orf72 hexanucleotide expansion fulfilled the diagnostic criteria for language variants of FTD, FTD-progressive supranuclear palsy overlap syndrome, dementia with Lewy bodies or Alzheimer's dementia. Conclusion: In a cohort of consecutive patients with EOD, 3.4% had the C9orf72 hexanucleotide expansion with clinical phenotypes of bvFTD or an overlap of bvFTD and MND. © 2015 S. Karger AG, Basel.

Background: Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia (EOD), characterized by behavioral changes (behavioral variant; bvFTD) or language deficits. A hexanucleotide repeat expansion in a noncoding region of chromosome 9 open reading frame 72 (C9orf72) has been proved to be a major cause of both familial and sporadic amyotrophic lateral sclerosis or FTD, with or without concomitant motor neuron disease (MND). Methods: The aim of this study was to assess the frequency of the C9orf72 hexanucleotide expansion in a cohort of 117 Serbian patients with EOD and to report phenotypic features of identified carriers. Results: We identified 4 of 117 (3.4%) patients with EOD to have C9orf72 hexanucleotide expansions. All patients were classified in the FTD disease spectrum group (8.2%): 3 patients fulfilled the criteria for bvFTD, and 1 patient had FTD-MND. None of the patients with the C9orf72 hexanucleotide expansion fulfilled the diagnostic criteria for language variants of FTD, FTD-progressive supranuclear palsy overlap syndrome, dementia with Lewy bodies or Alzheimer's dementia. Conclusion: In a cohort of consecutive patients with EOD, 3.4% had the C9orf72 hexanucleotide expansion with clinical phenotypes of bvFTD or an overlap of bvFTD and MND. © 2015 S. Karger AG, Basel.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular disorder caused by Notch3 gene mutations. The main histopathological hallmark is granular osmiophilic material (GOM) deposited in the close vicinity of vascular smooth muscle cells (VSMCs). The authors report the first 7 ultrastructurally and genetically confirmed cases of CADASIL in Serbia. Samples of skin and sural nerve were investigated by transmission electron microscopy. GOM deposits were observed around degenerated VSMCs in all the skin biopsies examined. Sural nerve biopsies revealed severe alterations of nerve fibers, endoneurial blood vessels with GOM deposits, endoneurial fibroblasts, and perineurial myofibroblasts. Total genomic DNA was extracted from peripheral blood leukocytes, and exons 26 of the Notch3 gene were amplified by PCR and subsequently sequenced. Four different mutations in exons 2 (Cys65Tyr), 3 (Gly89Cys and Arg90Cys), and 6 (Ala319Cys), which determine the CADASIL disease, were detected among all described patients. A novel missense mutation Gly89Cys involving exon 3 was detected. Due to the difficulties in the determination of the Notch3 mutations, these data suggest that electron microscopic analysis for GOMs in dermal vessel wall provides a rapid and reliable screening method for this disease. © 2012 Informa Healthcare USA, Inc.