Tomáš Sieger

Czech Technical University in Prague | ČVUT · Faculty of Electrical Engineering (FEL)

Objective: To assess the effect of overall, between- and within-day subjectively rated fluctuations in motor and non-motor symptoms in people with functional motor disorder (FMD) on the health-related quality of life (HRQoL). Background: FMD is a complex condition characterized by fluctuating motor and non-motor symptoms that may negatively impact...

Objective The role of inflammation and neuroimmune mechanisms, which have been documented in various neuropsychiatric disorders including the seizure subtype of functional neurological disorder, remains unclear in functional movement disorders (FMD). To explore these mechanisms, we analyzed selected inflammatory markers in cerebrospinal fluid (CSF)...

Sleep symptoms, including excessive sleepiness, are frequently reported by patients with functional motor disorders (FMD). We aimed to classify the comorbid sleep disorders in FMD, and to investigate the relationship between subjective sleepiness and objective measures of hypersomnia, comparing them with data from people with central hypersomnia. A...

In functional magnetic imaging (fMRI) in Parkinson’s disease (PD), a paradigm consisting of blocks of finger tapping and rest along with a corresponding general linear model (GLM) is often used to assess motor activity. However, this method has three limitations: (i) Due to the strong magnetic field and the confined environment of the cylindrical b...

In functional magnetic imaging (fMRI) in Parkinson's disease (PD), a paradigm consisting of blocks of finger tapping and rest along with a corresponding general linear model (GLM) is often used to assess motor activity. However, this method has three limitations: (i) Due to the Strong magnetic field and the confined environment of the cylindrical b...

Objective Pathophysiology explanations for functional movement disorders often assume a role for emotional hyperarousal. Pupillometry is a validated method for evaluation of emotional arousal by detecting changes in pupil size in response to emotional stimuli. In a case-control study design, we aimed to study objective and subjective emotional arou...

Background Patients with functional neurological disorders (FND) often present with multiple motor, sensory, psychological and cognitive symptoms. In order to explore the relationship between these common symptoms, we performed a detailed clinical assessment of motor, non-motor symptoms, health-related quality of life (HRQoL) and disability in a la...

We collected a multi-centric retrospective dataset of patients (N = 213) who were admitted to ten hospitals in Czech Republic and tested positive for SARS-CoV-2 during the early phases of the pandemic in March—October 2020. The dataset contains baseline patient characteristics, breathing support required, pharmacological treatment received and mult...

Hierarchical clustering is a common tool for simplification, exploration, and analysis of datasets in many areas of research. For data originating in flow cytometry, a specific variant of agglomerative clustering based Mahalanobis-average linkage has been shown to produce results better than the common linkages. However, the high complexity of comp...

Background Brain sensing devices are approved today for Parkinson's, essential tremor, and epilepsy therapies. Clinical decisions for implants are often influenced by the premise that patients will benefit from using sensing technology. However, artifacts, such as ECG contamination, can render such treatments unreliable. Therefore, clinicians need...

The nuclear pore complex (NPC) has emerged as a hub for the transcriptional regulation of a subset of genes, and this type of regulation plays an important role during differentiation. Nucleoporin TPR forms the nuclear basket of the NPC and is crucial for the enrichment of open chromatin around NPCs. TPR has been implicated in the regulation of tra...

Abstract Background The study analyzes changes in lung function, pulmonary pressure and diffusing capacity of the lung in patients with mitral valve regurgitation (MR) treated by MitraClip implantation. Methods A total of 43 patients (19 women and 24 men with an average age of 78.0 ± 6.6 years) who were able to perform pulmonary function testing in...

Background Abnormal findings at brain MRI in patients with neurologic Wilson disease (WD) are characterized by signal intensity changes and cerebral atrophy. T2 signal hypointensities and atrophy are largely irreversible with treatment; their relationship with permanent disability has not been systematically investigated. Purpose To investigate ass...

Objective Investigate the relationship between implant location and neural signal contamination with electrocardiographic (ECG) activity in bidirectional implantable neurostimulation systems used to evaluate closed-loop stimulation for neurological diseases. Methods Electric field modelling was used to predict the relevance of implant location to...

We collected a multi-centric retrospective dataset of patients (N = 213) who were admitted to ten hospitals in Czech Republic and tested positive for SARS-CoV-2. The dataset contains baseline patient characteristics, breathing support required, pharmacological treatment received and multiple markers on daily resolution. Patients in the dataset were...

ShinySOM offers a user-friendly interface for reproducible, high-throughput analysis of high-dimensional flow and mass cytometry data guided by self-organizing maps. The software implements a FlowSOM-style workflow, with improvements in performance, visualizations and data dissection possibilities. The outputs of the analysis include precise statis...

Clinical motor and non-motor effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD) seem to depend on the stimulation site within the STN. We analysed the effects of the position of the stimulation electrode within the motor STN on subjective emotional experience, expressed as emotional valence and arou...

Background Patients with functional movement disorders also typically have functional somatic symptoms, including pain, fatigue, and sensory disturbance. A potentially unifying mechanism for such symptoms is a failure in processing of sensory inputs. Prepulse inhibition is a neurophysiological method that allows for the study of preconscious somato...

The organization of the nuclear periphery is crucial for many nuclear functions. Nuclear lamins form dense network at the nuclear periphery and play a substantial role in chromatin organization, transcription regulation and in organization of nuclear pore complexes (NPCs). Here, we show that TPR, the protein located preferentially within the nuclea...

INTRODUCTION: The deep brain stimulation (DBS) is a treatment technique for late-stage Parkinson’s disease (PD), based on chronic electrical stimulation of neural tissue through implanted electrodes. To achieve high level of symptom suppression with low side effects, precise electrode placement is necessary, although difficult due to small size of...

The deep brain stimulation (DBS) is a symptomatic treatment technique used mainly for movement disorders, consisting of chronic electrical stimulation of subcortical structures. To achieve very precise electrode implantation, which is necessary for a good clinical outcome, many surgical teams use electrophysiological recording around the assumed ta...

Intraoperative microelectrode records (MER) are considered as the standard electrophysiological method for the precise positioning of the deep brain stimulation (DBS) electrode into the Globus pallidus interna (GPi). The final GPi position is chosen based on the firing patterns of individual neurons. Finding the number of neurons is usually done ma...

Background: Extracellular microelectrode recording (MER) is a prominent technique for studies of extracellular single-unit neuronal activity. In order to achieve robust results in more complex analysis pipelines, it is necessary to have high quality input data with a low amount of artifacts. We show that noise (mainly electromagnetic interference...

Nuclear periphery (NP) plays substantial role in chromatin organization. Heterochromatin at the NP is intermitted with active chromatin surrounding nuclear pore complexes (NPCs), however, details of the peripheral chromatin organization are missing. To discern the distributions of epigenetic marks at the NP of HeLa nuclei, we used structured illumi...

Disturbances of the gamma-aminobutyric-acid (GABA) system have been suspected of contributing to the pathophysiology of progressive supranuclear palsy (PSP). The ability to rapidly resolve competitive action decisions, such as shifting the gaze to one particular stimulus rather than another, can be predicted by the concentration of GABA in the regi...

Hierarchical cluster analysis is a valuable tool for exploring data by describing their structure using a dendrogram. However, proper visualization and interactive inspection of the dendrogram are needed to unlock the information in the data. We describe a new R package, idendro, that enables the user to inspect dendrograms interactively: to select...

We present a probabilistic model for classification of micro-EEG signals, recorded during deep brain stimulation surgery for Parkinson’s disease. The model uses parametric representation of neuronal background activity, estimated using normalized root-mean-square of the signal. Contrary to existing solutions using Bayes classifiers or Hidden Markov...

Introduction Changes in emotional processes have been reported after deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson’s disease (PD). The STN DBS increased activity of the aversive motivational system: the fearful stimuli were experienced as more salient with the DBS switched on. The STN is organized into a dorsolateral mo...

Objective: To analyze the effects of levodopa on affective ratings of emotional valence and arousal to rewarding, fearful and neutral stimuli in PD patients and matched controls. Background: Dopamine and deep brain stimulation (DBS) of the subthalamic nucleus (STN) have been shown to affect different aspects of emotional and motivational processes...

Background: Detailed study of the period before schizophrenic relapse when early warning signs (EWS) are present is crucial to effective pre-emptive strategies. Aims: To investigate the temporal properties of EWS self-reported weekly via a telemedicine system. Method: EWS history was obtained for 61 relapses resulting in hospitalization involv...

Objective The subthalamic nucleus (STN) is an important motor and non-motor hub. Animal studies suggest that the STN is also involved in perception, however evidence in humans is missing. We analyzed the visuo-attentional activity of STN neurons in Parkinson‘s disease (PD) patients. Methods Extracellular neuronal activity and electrooculography wa...

Objectives Considering the functional organization of the subthalamic nucleus (STN), we hypothesized that STN-DBS might have a differential impact on emotional reactivity in relation to the electrode position within the STN. We aimed to assess this objectively using affective modulation of the acoustic blink reflex (ABR). Methods ABR elicited duri...

Objective Anxiety is a common symptom of Parkinson’s disease (PD) negatively influencing quality of life. To identify brain regions associated with this symptom we compared resting brain connectivity to subjective assessment of anxiety. Participants and methods Using the resting state-fMRI (3T, TR = 2s, 300 scans) we analysed spontaneous signal fl...

Background: Falls are a common complication of advancing Parkinson's disease (PD). Although numerous risk factors are known, reliable predictors of future falls are still lacking. The objective of this prospective study was to investigate clinical and instrumented tests of balance and gait in both OFF and ON medication states and to verify their u...

Background: Cognitive decline, Parkinsonism and depression are frequent accompaniments of aging. Prevalence of these disorders rises together with age. Among residents of assisted living facilities there is presumption of higher occurrence of these disorders. Objective: To obtain a direct estimate of the prevalence of dementia, Parkinsonism and dep...

The number of patients suffering from Parkinson’s disease is increasing rapidly due to population aging. While traditional medications-based palliative therapy is successful in early stages, deep brain stimulation (DBS) may be used as an alternative treatment in later stages. After DBS implantation, the therapy typically consists of electrical stim...

Historical nomograms for the prediction of cancer on prostate biopsy, developed in the sextant biopsy era are no more accurate today. The aim of this study was an independent external validation of a 10-core biopsy nomogram by Chun et al. (2007). A total of 322 patients who presented for their initial biopsy in a tertiary care center and had all th...

Significance The involvement of the subthalamic nucleus (STN) in affective processing has been suggested with the appearance of neuropsychiatric side effects of deep brain stimulation in Parkinson’s disease (PD), but direct evidence has been lacking. In our study, we recorded single-neuron activity from the STN during affective picture presentation...

Patients with ephedrone parkinsonism (EP) show a complex, rapidly progressive, irreversible, and levodopa non-responsive parkinsonian and dystonic syndrome due to manganese intoxication. Eye movements may help to differentiate parkinsonian syndromes providing insights into which brain networks are affected in the underlying disease, but they have n...

Deep brain stimulation (DBS) of targets in basal ganglia is an effective treatment of motor dysfunction in Parkinson’s disease and primary dystonia. However this treatment may be accompanied by unwanted non-motor side effects. To confirm their neurophysiological nature we searched for any neurons in the subthalamic nucleus (STN), substantia nigra p...

The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channe...

To assist other eye movement investigators in the design and analysis of their studies. We examined basic saccadic eye movements and smooth pursuit in the horizontal and vertical directions with video-oculography in a group of 145 healthy subjects between 19 and 82years of age. Gender and education level did not influence eye movement metrics. With...

To tackle the heterogeneity of Parkinson's disease symptoms, most functional imaging studies tend to select a uniform group of subjects. We hypothesize that more profound considerations are needed to account for intra/inter-subject clinical variability and possibly for differing pathophysiological processes. Twelve patients were investigated using...

Electrode implantation into the subthalamic nucleus for deep brain stimulation in Parkinson's disease (PD) is associated with a temporary motor improvement occurring prior to neurostimulation. We studied this phenomenon by functional magnetic resonance imaging (fMRI) when considering the Unified Parkinson's Disease Rating Scale (UPDRS-III) and coll...

Individual description of the PD patient's group (N = 12). ID – patient's identification number; age – age of patient at surgery in years; G – gender: male (M); DD – duration of the PD in years; LD – duration of the levodopa treatment in years; MC – duration of motor complications in years; UPDRS-III in sessions 1–4: First number refers to OFF cond...

Patients with cervical dystonia (CD) present with an impaired performance of voluntary neck movements, which are usually slow and limited. We hypothesized that such abnormality could involve defective preparation for task execution. Therefore, we examined motor preparation in CD patients using the StartReact method. In this test, a startling audito...

Parkinson's disease (PD) is manifested by motor impairment, which may impede the ability to accurately perform motor tasks during functional magnetic resonance imaging (fMRI). Both temporal and amplitude deviations of movement performance affect the blood oxygenation level-dependent (BOLD) response. We present a general approach for assessing PD pa...

UPDRS-III* - Motor part of Unified Parkinson's Disease Rating Scale. G: gender. FS: First signs of the disease at age (years). LC: Late complications of the disease at age (years). LT: duration of levodopa treatment (years). OFF: without levodopa medication. ON: with levodopa medication. (DOC)

Disorders of balance and gait have been observed in patients with essential tremor (ET), but their association with tremor severity remains unclear. This study aimed to evaluate postural instability and gait changes in ET patients and to investigate their relationship to tremor characteristics with regard to cerebellar dysfunction as a possible com...

This paper focuses on wrapper-based feature selection for a 1-nearest neighbor classifier. We consider in particular the case of a small sample size with a few hundred instances, which is common in biomedical applications. We propose a technique for calculating the complete bootstrap for a 1-nearest-neighbor classifier (i.e., averaging over all des...

Proper classification of action potentials from extracellular recordings is essential for making an accurate study of neuronal behavior. Many spike sorting algorithms have been presented in the technical literature. However, no comparative analysis has hitherto been performed. In our study, three widely-used publicly-available spike sorting algorit...

Background Parkinson's disease (PD) patients are deficient in time estimation. This deficit improves after dopamine (DA) treatment and it has been associated with decreased internal timekeeper speed, disruption of executive function and memory retrieval dysfunction.Methodology/findingsThe aim of the present study was to explore the neurophysiologic...

Flow cytometry is a valuable tool in research and diagnostics including minimal residual disease (MRD) monitoring of hematologic malignancies. However, its gradual advancement toward increasing numbers of fluorescent parameters leads to information rich datasets, which are challenging to analyze by standard gating and do not reflect the multidimens...

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) can induce nonmotor side effects such as behavioral and mood disturbances or body weight gain in Parkinson's disease (PD) patients. We hypothesized that some of these problems could be related to an altered attribution of incentive salience (ie, emotional relevance) to rewarding and aver...

Patients with writer's cramp (WC) were studied for differences in cortical activation during movements likely to induce WC (complex movements) and movements which rarely lead to dystonia (simple movements). Eleven WC patients (10F, 1M, mean age 41.5 ± (SD)7.2 years) and eleven age matched controls were examined for Blood oxygenation-level dependent...

Proper classification of action potentials from extracellular recordings is essential for making an accurate study of neuronal behavior. Many spike sorting algorithms have been presented in the technical literature. However, no comparative analysis has hitherto been performed. In our study, three widely-used publicly-available spike sorting algorit...

One of the most difficult aspects of spike sorting is choosing the number of neurons in extracellular recording. The paper proposes a methodology for estimating the number of neurons based on the Gaussian mixture model. The following criteria have been examined: Bayesian selection method, Akaikes information criteria, minimum description length, mi...

Flow cytometry is an important tool both for research and diagnostics of hematologic malignancies - including monitoring of minimal residual disease (MRD). Recent progress and more widespread availability of 6 and higher color flow cytometry leads to complex, information-rich datasets which are very challenging to analyze. Here, we validate a novel...

6-color flow cytometry allows multiparameter analysis of high numbers of single cells. It is an excellent tool for the characterization of a wide range of hematopoietic populations and for monitoring minimal residual disease. However, analysis of complex flow data is challenging. Gating populations on 28 two-parameter plots is extremely tedious and...