Štefan Sivák
Comenius University in Bratislava
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Featured researches published by Štefan Sivák.
Brain Injury | 2008
Štefan Sivák; Egon Kurča; Mária Hladká; Kamil Zeleňák; Monika Turčanová-Koprušáková; Jozef Michalik
Introduction: Mild traumatic brain injury (MTBI) is a common neurotraumatologic diagnosis. It is possible to confirm objective cognitive impairment in MTBI patients not only by complex neuropsychological testing but also by event-related potentials (ERPs). The most common ERPs used in clinical practice are based on an oddball paradigm. Magnetic resonance imaging (MRI) is not routinely used in MTBI despite its proven greater sensitivity and specificity in comparison with computer tomography (CT). Methods: This study investigated 31 MTBI patients and 31 sex and age-matched healthy controls. Both groups underwent clinical neurological examinations. Auditory oddball ERPs and brain MRI were done early after the injury and 3–7 months later. Results: There were no significant sex, age and education differences between the analysed groups. No significant differences were found in N2 and P3 wave parameters in both ERP examinations. Conclusion: Standard auditory oddball ERPs are not sensitive enough to detect and/or quantify subtle objective neuropsychological changes in selected MTBI patients, especially those with traumatic MRI brain lesions. More complex auditory or other oddball paradigms have to be tested in the future.
Brain Injury | 2014
Štefan Sivák; Michal Bittšanský; J. Grossmann; Vladimir Nosal; Ema Kantorová; J. Siváková; A. Demková; Petra Hnilicová; Dusan Dobrota; Egon Kurča
Abstaract Introduction: Standard brain magnetic resonance imaging (MRI) is typically normal in most patients after mild traumatic brain injury (MTBI). Proton magnetic resonance spectroscopy (1H-MRS) is more sensitive to detect subtle post-traumatic changes. The aim of the study was to evaluate the clinical correlations of these changes in the acute phase (within 3 days) after MTBI. Methods: Twenty-one patients with MTBI and 22 controls were studied. Both groups underwent neuropsychological testing and single-voxel 1H-MRS examination of both frontal lobes and upper brainstem. Results: Significant decrease in NAA was found in both frontal lobes and in NAA/Cre ratio in the right frontal lobe (p < 0.05). Correlation analysis showed a correlation of NAA in the left frontal lobe with Backward Digit Span (p = 0.022) and Stroop test A (p = 0.0034) and a weak correlation with TMT B time (p = 0.046). The NAA/Cre in the right frontal lobe correlated with Stroop test A (p = 0.007) and with the total score of Digit Span (p = 0.016). Lower NAA was found in the upper brainstem (p = 0.0157) in the sub-group of patients with post-traumatic unconsciousness. Conclusions: This study found a correlation of 1H-MRS metabolite changes with cognitive decline and presence or absence of loss of consciousness in the acute phase after MTBI.
Neurological Research | 2016
Daniel Čierny; Jozef Michalik; Mária Škereňová; Ema Kantorová; Štefan Sivák; Juraj Javor; Egon Kurča; Dusan Dobrota; Ján Lehotský
Objective: Vitamin D acts through vitamin D receptor (VDR) and has promising beneficial effects in the development and progression of multiple sclerosis (MS). The purpose of our study was to investigate the possible association of the VDR gene polymorphisms ApaI, BsmI and TaqI with the MS susceptibility and with the rate of disease disability progression in the Central European Slovak population. Methods: The allele and genotype variants of ApaI, TaqI and BsmI VDR gene polymorphisms were analysed in 270 clinically diagnosed MS patients and 303 healthy controls. Genotyping was performed by polymerase chain reaction and restriction analysis. Patients were stratified by the rate of disease disability progression using MSSS scores. Results: By logistic regression analysis, we revealed that genotype BB (AA) of BsmI VDR gene polymorphism is decreasing the risk of MS (BB (AA) vs Bb (AG) + bb (GG); OR = 0.59, 95% CI = 0.39–0.90, plog = 0.014). We did not identify any association of ApaI and TaqI polymorphisms neither with MS development nor with the disease progression. Discussion: We showed for the first time that BsmI genotype BB (AA) is associated with the decreased susceptibility to MS in Slovak population. We propose the BsmI gene polymorphism to be one of the important genetic markers in evaluation of the risk of MS. However, our data suggest that VDR gene polymorphisms ApaI, BsmI and TaqI are not useful in the prediction of disease disability progression rate in MS in Slovaks.
International Journal of Endocrinology | 2015
Ema Kantorová; Ľubica Jesenská; Daniel Čierny; Kamil Zeleňák; Štefan Sivák; Matej Stančík; Peter Galajda; Vladimír Nosáľ; Egon Kurča
Cerebrovascular disorders, particularly ischemic stroke, are one of the most common neurological disorders. High rates of overweight and obesity support an interest in the role of adipose tissue and adipose tissue releasing cytokines in inducing associated comorbidities. Adipokines can serve as a key messenger to central energy homeostasis and metabolic homeostasis. They can contribute to the crosstalk between adipose tissue and brain. However recent research has offered ambiguous data on the network of adipose tissue, adipokines, and vascular disorders. In our paper we provide a critical insight into the role of adipokines in evolution of ischemic stroke.
Neurological Research | 2017
Ema Kantorová; Hubert Poláček; Michal Bittšanský; Eva Baranovicova; Petra Hnilicová; Daniel Čierny; Štefan Sivák; V. Nosáľ; Kamil Zeleňák; Egon Kurča
Abstract Objectives: Disturbances in the hypothalamo-pituitary axis are supposed to modulate activity of multiple sclerosis (MS). We hypothesised that the extent of HYP damage may determine severity of MS and may be associated with the disease evolution. We suggested fatigue and depression may depend on the degree of damage of the area. Method: 33 MS patients with relapsing-remitting and secondary progressive disease, and 24 age and sex-related healthy individuals (CON) underwent 1H-MR spectroscopy (1H-MRS) of the hypothalamus. Concentrations of glutamate + glutamin (Glx), cholin (Cho), myoinositol (mIns), N-acetyl aspartate (NAA) expressed as ratio with creatine (Cr) and NAA were correlated with markers of disease activity (RIO score), Multiple Sclerosis Severity Scale (MSSS), Depressive-Severity Status Scale and Simple Numerical Fatigue Scale. Results: Cho/Cr and NAA/Cr ratios were decreased and Glx/NAA ratio increased in MS patients vs CON. Glx/NAA, Glx/Cr, and mIns/NAA were significantly higher in active (RIO 1–2) vs non-active MS patients (RIO 0). Glx/NAA and Glx/Cr correlated with MSSS and fatigue score, and Glx/Cr with depressive score of MS patients. In CON, relationships between Glx/Cr and age, and Glx/NAA and fatigue score were inverse. Conclusion: Our study provides the first evidence about significant hypothalamic alterations correlating with clinical outcomes of MS, using 1H-MRS. The combination of increased Glu or mIns with reduced NAA in HYP reflects whole-brain activity of MS. In addition, excess of Glu is linked to severe disease course, depressive mood and fatigue in MS patients, suggesting superiority of Glu over other metabolites in determining MS burden.
Biomedical Papers-olomouc | 2016
Jana Dluha; Štefan Sivák; Egon Kurča; R. Dusenka; Klaudia Kalmarova; Monika Turčanová Koprušáková; Ema Kantorová; Vladimir Nosal
AIMS This study aimed to compare the efficacy and safety of heparin and nadroparin in order to provide an additional therapeutic option for patients with acute ischemic stroke in, whom systemic thrombolysis was excluded, or thrombectomy could not be performed. METHODS We describe a prospective randomized double-blind placebo-controlled pilot study in acute ischemic stroke. The therapeutic window was between 4.5 and 24 h after the onset of stroke. During the first 24 h of treatment, the patients divided into 3 groups received placebo, heparin or nadroparin (in therapeutic doses). During the following 48 h, each patient received nadroparin in the therapeutic dose. 24 h after start of treatment they began taking 100 mg aspirin daily. The primary safety indicator was incidence of complications such as intracerebral or systemic hemorrhage, or death. Efficacy was primarily monitored by the neurological modified Rankin Scale (mRS) at 90 days. RESULTS There were no signs of intracerebral or systemic bleeding in the cohort of 87 patients. Two patients died - one (3.7%) in the heparin and one (3.8%) in the placebo group due to causes not connected with the treatment. There was a statistically significant difference in mRS on the 90th day between the heparin and placebo groups (21 (80%) vs 13 (50%), P=0.0350) and between the nadroparin and placebo groups (29 (85%) vs 13 (50%), P=0.0031). CONCLUSION The results show that the treatment with heparin and nadroparin is safe and effective. TRIAL REGISTRATION Trial is registered in ClinicalTrials.gov: NCT01862978.
Spinal Cord | 2015
Ema Kantorová; Juraj Marcinek; Kamil Zeleňák; K Kantor; Jozef Michalik; Štefan Sivák; Egon Kurča; Plank L
Study design:Case report.Objectives:We report on a 52-year-old male patient with tumefactive demyelination of the spinal cord.Setting:University Hospital and Jessenius Faculty of Medicine, Comenius University, Martin, Slovakia.Background:In contrast to relatively frequent tumefactive fulminant lesions in the brain, cases affecting the spinal cord in isolation have been reported less frequently.Methods:Description of the case report.Results:Clinical, neuroradiological and necropsy findings are described in a 52-year-old man with tumefactive fulminant demyelination of the spinal cord. Progression of the demyelination process produced paraplegia, mild paresis of the right upper limb, neurogenic bladder and sensitive loss over 2 weeks. MRI scans revealed several ovoid lesions in cervical segments and tumefactive T2-hyperintense signals with oedema and post-contrast enhancement located in thoracic segments Th3 to Th6. Cerebrospinal fluid (CSF) examination displayed lymphomonocytic pleocytosis with normal proteinorhachia, positive CSF oligoclonal IgG bands (OCB) and elevated IgG index (1.55). Serum anti-AQP4-Ab was not tested. Stored frozen CSF samples were later repeatedly examined with negative findings of anti-AQP4-Ab. Treatment with high-dose methylprednisolon and plasma exchange had limited effect. Immunosuppressive medication was interrupted because of an acute urinary infection. The patient died suddenly because of pulmonary embolism as a secondary complication. Histopathology of the spinal cord confirmed active demyelination. We considered that tumefactive demyelination could be a variant of neuromyelitis optica.Conclusion:Our case could be anti-AQP4-Ab-negative longitudinally extensive transverse myelitis, a variant of neuromyelitis optica.
Biomedical Papers-olomouc | 2017
Andrea Petrovičová; Miroslav Brozman; Egon Kurča; Tibor Göbö; Jana Dluha; Klaudia Kalmarova; Vladimir Nosal; Martina Hikkelová; Adriána Krajčiová; Tatiana Burjanivova; Štefan Sivák
INTRODUCTION Episodic ataxias (EAs) are rare dominantly inherited neurological disorders characterized by recurrent episodes of ataxia lasting minutes to hours. The most common subtype is EA type 2 (EA2) caused by pathogenic variants of calcium voltage-gated channel subunit alpha1 A gene (CACNA1A) on chromosome 19p13. SUBJECTS AND METHODS We examined a Slovak three-generation family. Genomic DNA of the family members was extracted from peripheral blood and amplified by polymerase chain reaction. CACNA1A variants were screened by Sanger sequencing. RESULTS We identified four family members with recurrent episodes of ataxia. Complex differential diagnosis was performed. Genetic analysis with direct sequencing revealed a novel heterozygous variant of CACNA1A - c.5264A>G (p.Glu1755Gly) located in the pore loop of domain IV of calcium channel alpha-1A subunit. CONCLUSION We identified a novel missense variant of a voltage-dependent P/Q-type calcium channel alpha-1A subunit in a Slovak three-generation family with recurrent episodes of ataxia. The heterozygous missense variant resulted in changing a highly conserved glutamic acid within the pore loop of domain IV.
Neurological Research | 2018
Daniel Čierny; Ján Lehotský; Ema Kantorová; Štefan Sivák; Juraj Javor; Egon Kurča; Dusan Dobrota; Jozef Michalik
Abstract Objective: The aim of our present study was to analyse the association of HLA-DRB1 and -DQB1 alleles and genotypes with Multiple Sclerosis (MS) disability progression in a cohort of Central European Slovak population. Methods: The allele and genotype variants were analyzed in 282 non-related MS patients. Rate of disease disability progression was evaluated using EDSS score in the 5th, 7th, 10th, and 15th year of disease duration, time to reach EDSS score 3 and 5, and MSSS score. Genotyping was performed by polymerase chain reaction with sequence-specific primers. Results: We found that carriers of homozygous genotype for alleles DRB1*15 and DQB1*03 reached EDSS score 3 significantly earlier than non-carriers of these alleles (p = 0.0172; p = 0.00183, respectively). Genotype DQB1*03/03 carriage was also associated with significantly reduced time to reach EDSS score 5 (p = 0.00316). Lower EDSS score in the 5th year of disease duration was found in carriers of DRB1*07 allele (p cor = 0.028). When MSSS score was used, genotype DRB1*15/15 was found to be less frequent in slow progressing MS patients, when compared to MS patients with mid-rate and rapid disease disability progression (p cor = 0.0305). Discussion: We showed for the first time that HLA-DRB1 and -DQB1 genotypes are genetic markers associated with disability progression in Slovak MS patients. Genotypes DRB1*15/15 and DQB1*03/*03 were identified as short-term clinical negative prognostic factors, while allele DRB1*07 carriage appeared to be a positive prognostic marker of better MS outcome.
BMC Cancer | 2017
Ema Kantorová; Michal Bittšanský; Štefan Sivák; Eva Baranovicova; Petra Hnilicová; Vladimír Nosáľ; Daniel Čierny; Kamil Zeleňák; Wolfgang Brück; Egon Kurča
BackgroundCo-occurrence of multiple sclerosis (MS) and glial tumours (GT) is uncommon although occasionally reported in medical literature. Interpreting the overlapping radiologic and clinical characteristics of glial tumours, MS lesions, and progressive multifocal leukoencephalopathy (PML) can be a significant diagnostic challenge.Case presentationWe report a case of anaplastic astrocytoma mimicking PML in a 27-year-old patient with a 15-year history of MS. She was treated with interferon, natalizumab and finally fingolimod due to active MS. Follow-up MRI, blood and cerebrospinal fluid examinations, and biopsy were conducted, but only the latter was able to reveal the cause of progressive worsening of patient’s disease.ConclusionsAnaplastic astrocytoma misdiagnosed as PML has not yet been described. We suppose that the astrocytoma could have evolved from a low grade glioma to anaplastic astrocytoma over time, as the tumour developed adjacent to typical MS plaques. The role of the immunomodulatory treatment as well as other immunological factors in the malignant transformation can only be hypothesised. We discuss clinical, laboratory and diagnostic aspects of a malignant GT, MS lesions and PML. The diagnosis of malignant GT must be kept in mind when an atypical lesion develops in a patient with MS.