Browsing by Author "Radovanović, Saša (6604015284)"

Background: The aim of the study was to assess gait pattern of patients diagnosed with fibromyalgia (FM) while performing demanding motor and/or cognitive dual tasks while walking. Further, idea was to explore possible correlations of dual task gait pattern alterations to patients’ functional status and presence or absence of clinical symptoms associated with FM. Methods: Twenty-four female FM patients and 24 healthy female subjects performed a basic walking task, a dual motor, a dual mental (cognitive) and a combined, dual motor and cognitive task simultaneously. Quantitative spatial (stride length) and temporal (cycle time, swing time and double support time) gait parameters were measured using GAITRite walkway system and their variability was assessed. Patients underwent clinical examination including assessment of functional status, pain and fatigue level, psychiatric and cognitive manifestations. Results: The motor, cognitive and combined dual tasks affect gait performance in FM patients. Difference in tasks between FM and healthy subjects was found as double support time prolongation. Comparison of tasks showing that cycle time in FM was longer than controls and stride length was shorter in patients for all conditions, while no changes were found in any of the gait parameters variability. Further, mental/cognitive dual tasks had a larger effect than motor tasks. Correlations were also found between depression and functional status of the patients and the gait parameters. Conclusions: Gait is affected in FM patients while dual task walking. No changes in stride-to-stride variability point that patients preserve stability in complex walking situations. Analysis of gait may provide additional information for the FM identification based on presence of clinical features and cognitive status. Correlation of dual task gait alterations with occurrence of clinical symptoms and influence of cognitive changes on gait pattern could additionally define FM subgroups. © 2021, The Author(s).

Introduction: Impulsive compulsive behaviors (ICBs) in Parkinson’s disease (PD) are debilitating disorders of repetitive, excessive, and compulsive nature affecting up to one third of PD patients. Objectives are to address clinical, psychiatric, and cognitive characteristics of ICBs and to define risk factors in PD patients in the initial motor stage, followed up for 5 years. Methods: We analyzed 106 consecutive PD outpatients at Hoehn and Yahr disease stage 1 and 125 healthy controls. The participants were assessed for the presence of any ICB using the current clinical criteria and underwent comprehensive clinical, psychiatric, and neuropsychological evaluations. The patients completed the same protocol at Years 1, 2, 3, and 5. Results: ICBs were present in 21 (19.8%) PD patients and 13 (10.4%) healthy controls at baseline. Prevalence of ICBs increased to 29.2% at Year 5, significantly after Year 2. Multiple ICBs were present in 4,7% and 61.9% of PD-ICBs at the baseline and Year 5, respectively. ICBs resolved in 30% of cases (most often compulsive eating). Dopamine agonist treatment at the baseline carried five times higher risk of having or developing ICB(s) anytime during follow-up. We identified risk factors for compulsive eating (dopamine agonist treatment at baseline), hypersexuality (males), compulsive buying (depression and younger age), and punding (younger age and higher levodopa dose at baseline). Significant interaction of rate of motor progression and ICB diagnosis was shown. Conclusions: PD patients showed increasing frequency of most ICBs during the 5-year follow-up. Specific risk factors were identified for different types of ICBs. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

Introduction: Impulsive compulsive behaviors (ICBs) in Parkinson’s disease (PD) are debilitating disorders of repetitive, excessive, and compulsive nature affecting up to one third of PD patients. Objectives are to address clinical, psychiatric, and cognitive characteristics of ICBs and to define risk factors in PD patients in the initial motor stage, followed up for 5 years. Methods: We analyzed 106 consecutive PD outpatients at Hoehn and Yahr disease stage 1 and 125 healthy controls. The participants were assessed for the presence of any ICB using the current clinical criteria and underwent comprehensive clinical, psychiatric, and neuropsychological evaluations. The patients completed the same protocol at Years 1, 2, 3, and 5. Results: ICBs were present in 21 (19.8%) PD patients and 13 (10.4%) healthy controls at baseline. Prevalence of ICBs increased to 29.2% at Year 5, significantly after Year 2. Multiple ICBs were present in 4,7% and 61.9% of PD-ICBs at the baseline and Year 5, respectively. ICBs resolved in 30% of cases (most often compulsive eating). Dopamine agonist treatment at the baseline carried five times higher risk of having or developing ICB(s) anytime during follow-up. We identified risk factors for compulsive eating (dopamine agonist treatment at baseline), hypersexuality (males), compulsive buying (depression and younger age), and punding (younger age and higher levodopa dose at baseline). Significant interaction of rate of motor progression and ICB diagnosis was shown. Conclusions: PD patients showed increasing frequency of most ICBs during the 5-year follow-up. Specific risk factors were identified for different types of ICBs. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

Background/Aim. Finger tapping test is commonly used in neurological examinations as a test of motor performance. The new system comprising inertial and force sensors and custom proprietary software was developed for quantitative estimation and assessment of finger and foot tapping tests. The aim of this system was to provide diagnosis support and objective assessment of motor function. Methods. Miniature inertial sensors were placed on fingertips and used for measuring finger movements. A force sensor was placed on the fingertip of one finger, in order to measure the force during tapping. For foot tapping assessment, an inertial sensor was mounted on the subject’s foot, which was placed above a force platform. By using this system, various parameters such as a number of taps, tapping duration, rhythm, open and close speed, the applied force and tapping angle, can be extracted for detailed analysis of a patient’s motor performance. The system was tested on 13 patients with Parkinson’s disease and 14 healthy controls. Results. The system allowed easy measurement of listed parameters, and additional graphical representation showed quantitative differences in these parameters between neurological patient and healthy subjects. Conclusion. The novel system for finger and foot tapping test is compact, simple to use and efficiently collects patient data. Parameters measured in patients can be compared to those measured in healthy subjects, or among groups of patients, or used to monitor progress of the disease, or therapy effects. Created data and scores could be used together with the scores from clinical tests, providing the possibility for better insight into the diagnosis. © 2018, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved.

The goal of this study was to investigate repetitive finger tapping patterns in patients with Parkinson's disease (PD), progressive supranuclear palsy-Richardson syndrome (PSP-R), or multiple system atrophy of parkinsonian type (MSA-P). The finger tapping performance was objectively assessed in PD (n = 13), PSP-R (n = 15), and MSA-P (n = 14) patients and matched healthy controls (HC; n = 14), using miniature inertial sensors positioned on the thumb and index finger, providing spatio-temporal kinematic parameters. The main finding was the lack or only minimal progressive reduction in amplitude during the finger tapping in PSP-R patients, similar to HC, but significantly different from the sequence effect (progressive decrement) in both PD and MSA-P patients. The mean negative amplitude slope of -0.12°/cycle revealed less progression of amplitude decrement even in comparison to HC (-0.21°/cycle, p = 0.032), and particularly from PD (-0.56°/cycle, p = 0.001), and MSA-P patients (-1.48°/cycle, p = 0.003). No significant differences were found in the average finger separation amplitudes between PD, PSP-R and MSA-P patients (pmsa-pd = 0.726, pmsa-psp = 0.363, ppsp-pd = 0.726). The lack of clinically significant sequence effect during finger tapping differentiated PSP-R from both PD and MSA-P patients, and might be specific for PSP-R. The finger tapping kinematic parameter of amplitude slope may be a neurophysiological marker able to differentiate particular forms of parkinsonism. © 2016 Elsevier Ltd. All rights reserved.

The goal of this study was to investigate repetitive finger tapping patterns in patients with Parkinson's disease (PD), progressive supranuclear palsy-Richardson syndrome (PSP-R), or multiple system atrophy of parkinsonian type (MSA-P). The finger tapping performance was objectively assessed in PD (n = 13), PSP-R (n = 15), and MSA-P (n = 14) patients and matched healthy controls (HC; n = 14), using miniature inertial sensors positioned on the thumb and index finger, providing spatio-temporal kinematic parameters. The main finding was the lack or only minimal progressive reduction in amplitude during the finger tapping in PSP-R patients, similar to HC, but significantly different from the sequence effect (progressive decrement) in both PD and MSA-P patients. The mean negative amplitude slope of -0.12°/cycle revealed less progression of amplitude decrement even in comparison to HC (-0.21°/cycle, p = 0.032), and particularly from PD (-0.56°/cycle, p = 0.001), and MSA-P patients (-1.48°/cycle, p = 0.003). No significant differences were found in the average finger separation amplitudes between PD, PSP-R and MSA-P patients (pmsa-pd = 0.726, pmsa-psp = 0.363, ppsp-pd = 0.726). The lack of clinically significant sequence effect during finger tapping differentiated PSP-R from both PD and MSA-P patients, and might be specific for PSP-R. The finger tapping kinematic parameter of amplitude slope may be a neurophysiological marker able to differentiate particular forms of parkinsonism. © 2016 Elsevier Ltd. All rights reserved.

Depressed patients demonstrate alterations in motor and cognitive functioning that can affect their adjustments to the variations in everyday life environment. The objective was to explore gait parameters and variability of patients with major depressive disorder in dual task walking situations. Eight patients and 20 healthy controls performed motor, mental and combined motor+mental tasks while walking. Calculated parameters were cycle time, stride length, swing time, double support time and their coefficients of variation (CV). Patients demonstrated greater gait variability (swing time CV) than controls during baseline walk (t(26)=2.64, p<0.05) and motor dual task (t(26)=3.68, p<0.05). Moreover, the transition from mental to combined task decreased stride length (M=126.48±15.35 and M=121.19±13.55, p<0.001) and increased double support time (M=0.266±0.072 and M=0.287±0.076, p<0.01) only in controls. Also, gait variability increased in controls during the combined task, while remaining the same or decreasing in patients. Tasks that required greater cognitive involvement affected gait variability in patients more than controls, but only up to a certain level, after which patients[U+05F3] stability appeared unaffected by the increase of cognitive demand. This could be explained by a tendency of patients to neglect complex cognitive tasks while walking in order to preserve stability and prevent possible falls. © 2014 Elsevier Ireland Ltd.

Depressed patients demonstrate alterations in motor and cognitive functioning that can affect their adjustments to the variations in everyday life environment. The objective was to explore gait parameters and variability of patients with major depressive disorder in dual task walking situations. Eight patients and 20 healthy controls performed motor, mental and combined motor+mental tasks while walking. Calculated parameters were cycle time, stride length, swing time, double support time and their coefficients of variation (CV). Patients demonstrated greater gait variability (swing time CV) than controls during baseline walk (t(26)=2.64, p<0.05) and motor dual task (t(26)=3.68, p<0.05). Moreover, the transition from mental to combined task decreased stride length (M=126.48±15.35 and M=121.19±13.55, p<0.001) and increased double support time (M=0.266±0.072 and M=0.287±0.076, p<0.01) only in controls. Also, gait variability increased in controls during the combined task, while remaining the same or decreasing in patients. Tasks that required greater cognitive involvement affected gait variability in patients more than controls, but only up to a certain level, after which patients[U+05F3] stability appeared unaffected by the increase of cognitive demand. This could be explained by a tendency of patients to neglect complex cognitive tasks while walking in order to preserve stability and prevent possible falls. © 2014 Elsevier Ireland Ltd.

Background: Motor symptoms in Parkinson’s disease (PD) are typically asymmetrical. Early stage of PD is characterised with a predominantly unilateral appearance of tremor, rigidity and bradykinesia, with or without axial involvement. Also, studies have demonstrated gait asymmetry in de novo drug naïve PD patients. Aim of this study was to investigate gait pattern, gait symmetry and gait variability in early phases of PD. Methods: The gait was measured in 40 de novo, drug naïve PD patients and 43 healthy control subjects (HC) while performing a simple walking task. Calculated parameters were cycle time (CT), stride length (SL) and swing time (ST), and their coefficients of variation (CV). Results: Considering gait parameters, PD patients and HC differed in terms of all parameters, except for the CV of CT. Analysis of gait symmetry, comparison between the gait patterns of the left and the right leg in PD patients revealed no difference for any of the assessed parameters. The majority of the gait parameters did not differ between left and right legs of HC. Conclusions: It can be concluded that even gait was already altered in de novo drug naive PD patients, gait symmetry remained preserved. The SL was the most prominent parameter of altered gait in initial stages of PD patients, while the ST heralded postural asymmetry. © W. S. Maney & Son Ltd 2015.

Background: Motor symptoms in Parkinson’s disease (PD) are typically asymmetrical. Early stage of PD is characterised with a predominantly unilateral appearance of tremor, rigidity and bradykinesia, with or without axial involvement. Also, studies have demonstrated gait asymmetry in de novo drug naïve PD patients. Aim of this study was to investigate gait pattern, gait symmetry and gait variability in early phases of PD. Methods: The gait was measured in 40 de novo, drug naïve PD patients and 43 healthy control subjects (HC) while performing a simple walking task. Calculated parameters were cycle time (CT), stride length (SL) and swing time (ST), and their coefficients of variation (CV). Results: Considering gait parameters, PD patients and HC differed in terms of all parameters, except for the CV of CT. Analysis of gait symmetry, comparison between the gait patterns of the left and the right leg in PD patients revealed no difference for any of the assessed parameters. The majority of the gait parameters did not differ between left and right legs of HC. Conclusions: It can be concluded that even gait was already altered in de novo drug naive PD patients, gait symmetry remained preserved. The SL was the most prominent parameter of altered gait in initial stages of PD patients, while the ST heralded postural asymmetry. © W. S. Maney & Son Ltd 2015.

Objective: The goal of this study was to analyze how depression associated with Parkinson's disease (PD) affected gait variability in these patients using a dual-task paradigm. Additionally, the dependency of the executive functions and the impact of depression on gait variability were analyzed. Patients and Methods: Three subject groups were included: patients with PD, but no depression (PD-NonDep; 14 patients), patients with both PD and depression (PD-Dep; 16 patients) and healthy controls (HC; 15 subjects). Gait was recorded using the wireless sensors. The participants walked under four conditions: single-task, motor dual- task, cognitive dual-task, and combined dual-task. Variability of stride length, stride duration, and swing time was calculated and analyzed using the statistical methods. Results: Variability of stride duration and stride length were not significantly different between PD-Dep and PD-NonDep patients. The linear mixed model showed that swing time variability was statistically significantly higher in PD-Dep patients compared to controls (p = 0.001). Hamilton Disease Rating Scale scores were significantly correlated with the swing time variability (p = 0.01). Variability of all three parameters of gait was significantly higher while performing combined or cognitive task and this effect was more pronounced in PD-Dep group of patients. Conclusions: Depression in PD was associated with swing time variability, and this effect was more prominent while performing a dual-task. Significance: Diagnosing and treating depression might be important for gait improvement and fall reduction in PD patients. © 2020 Elsevier B.V.

Background Leber hereditary optic neuropathy (LHON) is the most common mitochondrial disorder. However, few countries have published their population-based findings related to this multisystemic disease. The aim In order to get a better insight into the epidemiological and clinical picture of this maternally inherited disorder, we performed the first population-based clinical and molecular-genetic study of LHON in the Serbian population. Methods Prospective study included patients who were diagnosed with LHON after detailed medical examination and molecular-genetic confirmation. Results We identified 41 individuals from 12 genealogically unrelated families, carrying one of the three "primary" mitochondrial (mt) DNA point mutations associated with LHON. Fourteen of them were clinically affected, giving a minimum point prevalence of 1.9 per 1 000 000. The minimum point prevalence for mtDNA LHON mutations was 5.2 per 1 000 000. Male to female ratio was 6:1. Only one affected patient harboured mutant mtDNA in heteroplasmic condition. All patients were presented with common clinical findings. Conclusion We observed significantly lower prevalence and higher gender ratio than expected. However, frequencies of primary mutations, incidence of heteroplasmy and clinical findings are in accordance with other studies in Caucasoid populations. Our results might be a consequence of poor recognition and misdiagnosis due to lack of diagnostic possibilities of the entity in different region of our country or less likely be in part due to specific haplotype background of Serbian population which should be further investigated. © 2013 Published by Elsevier Ltd on behalf of European Paediatric Neurology Society.

Introduction Repetitive transcranial magnetic stimulation (rTMS) is a method of brain stimulation which is increasingly used in both clinical practice and research. Up-to-date studies have pointed out a potential antidepressive effect of rTMS, but definitive superiority over placebo has not yet been confirmed. Objective The aim of the study was to examine the effect of rTMS as an adjuvant treatment with antidepressants during 18 weeks of evaluation starting from the initial application of the protocol. Methods Four patients with the diagnosis of moderate/severe major depression were included in the study. The protocol involved 2000 stimuli per day (rTMS frequency of 10 Hz, intensity of 120% motor threshold) administered over the left dorsolateral prefrontal cortex (DLPFC) for 15 days. Subjective and objective depressive symptoms were measured before the initiation of rTMS and repeatedly evaluated at week 3, 6, 12 and 18 from the beginning of the stimulation. Results After completion of rTMS protocol two patients demonstrated a reduction of depressive symptoms that was sustained throughout the 15-week follow-up period. One patient showed a tendency of remission during the first 12 weeks of the study, but relapsed in week 18. One patient showed no significant symptom reduction at any point of follow-up. Conclusion Preliminary findings suggest that rTMS has a good tolerability and can be efficient in accelerating the effect of antidepressants, particularly in individuals with shorter duration of depressive episodes and moderate symptom severity. Keywords: transcranial magnetic stimulation; depression; an-tidepressants; HAMD. © 2014, Serbia Medical Society. All rights reserved.

Background: Gait disturbances are an integral part of clinical manifestations of Parkinson’s disease (PD), even in the initial stages of the disease. Our goal was to identify the set of spatio-temporal gait parameters that bear the highest relevance for characterizing de novo PD patients. Methods: Forty patients with de novo PD and forty healthy controls were recorded while walking over an electronic walkway in three different conditions: (1) base walking, (2) walking with an additional motor task, (3) walking with an additional mental task. Both groups were well balanced concerning age and gender. To select a smaller number of relevant parameters, affinity propagation clustering was applied on parameter pairwise correlation. The exemplars were then sorted by importance using the random forest algorithm. Classification accuracy of a support vector machine was tested using the selected parameters and compared to the accuracy of the model using a set of parameters derived from literature. Results: Final selection of parameters included: stride length and stride length coefficient of variation (CV), stride time and stride time CV, swing time and swing time CV, step time asymmetry, and heel-to-heel base support CV. Classification performed using these parameters showed higher overall accuracy (85%) than classification using the common parameter set containing: stride time, stride length, swing time and double support time, along with their CVs (78%). Conclusion: In early stages of PD, double support time and its CV appear to be weak indicators of the disease. We instead found step time asymmetry and support base CV to significantly contribute to classification accuracy. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Background: Gait disturbances are an integral part of clinical manifestations of Parkinson’s disease (PD), even in the initial stages of the disease. Our goal was to identify the set of spatio-temporal gait parameters that bear the highest relevance for characterizing de novo PD patients. Methods: Forty patients with de novo PD and forty healthy controls were recorded while walking over an electronic walkway in three different conditions: (1) base walking, (2) walking with an additional motor task, (3) walking with an additional mental task. Both groups were well balanced concerning age and gender. To select a smaller number of relevant parameters, affinity propagation clustering was applied on parameter pairwise correlation. The exemplars were then sorted by importance using the random forest algorithm. Classification accuracy of a support vector machine was tested using the selected parameters and compared to the accuracy of the model using a set of parameters derived from literature. Results: Final selection of parameters included: stride length and stride length coefficient of variation (CV), stride time and stride time CV, swing time and swing time CV, step time asymmetry, and heel-to-heel base support CV. Classification performed using these parameters showed higher overall accuracy (85%) than classification using the common parameter set containing: stride time, stride length, swing time and double support time, along with their CVs (78%). Conclusion: In early stages of PD, double support time and its CV appear to be weak indicators of the disease. We instead found step time asymmetry and support base CV to significantly contribute to classification accuracy. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

The effects of prior vibration of the antagonist triceps muscle on the performance of rapid discrete elbow flexion movements were studied in healthy volunteers. The subjects performed 520 movements over five experimental sessions. The application of prior vibration resulted in a shift of the initial position, an undershoot of the final position in untrained subjects, and also in trained subjects if not applied during practice. On the contrary, no undershoot occurred in trained subjects when prior vibration was applied during practice. Improvement in movement performance, as judged by a decrease in variability of the final position, was less successful when vibration was applied during practice. It is supposed that the undershoots were due to prior vibration-induced alterations in proprioceptive messages and a consequent erroneous sense of the arm position. These effects seem to be overcome by practice, but also seem to interfere with learning-based movement improvement.

The effects of prior vibration of the antagonist triceps muscle on the performance of rapid discrete elbow flexion movements were studied in healthy volunteers. The subjects performed 520 movements over five experimental sessions. The application of prior vibration resulted in a shift of the initial position, an undershoot of the final position in untrained subjects, and also in trained subjects if not applied during practice. On the contrary, no undershoot occurred in trained subjects when prior vibration was applied during practice. Improvement in movement performance, as judged by a decrease in variability of the final position, was less successful when vibration was applied during practice. It is supposed that the undershoots were due to prior vibration-induced alterations in proprioceptive messages and a consequent erroneous sense of the arm position. These effects seem to be overcome by practice, but also seem to interfere with learning-based movement improvement.

We are presenting two Leber's hereditary optic neuropathy (LHON) pedigrees with abnormal magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (H-MRS) findings but without neurological manifestation associated with LHON. The study included 14 LHON patients and 41 asymptomatic family members from 12 genealogically unrelated families. MRI showed white matter involvement and H-MRS exhibited metabolic anomalies within 12 LHON families. Main outcome measures were abnormal MRI and H-MRS findings in two pedigrees. MRI of the proband of the first pedigree showed a single demyelinating lesion in the right cerebellar hemisphere, while the proband of the second family displayed multiple supratentorial and infratentorial lesions, compatible with the demyelinating process, and both the absolute choline (Cho) concentration and Cho/creatinine ratio were increased. MRI and H-MRS profiles of both affected and unaffected mitochondrial DNA mutation carriers suggest more widespread central nervous involvement in LHON. Although even after 12 years our patients did not develop neurological symptoms, MRI could still be used to detect possible changes during the disease progression. © 2015 S. Karger AG.