Publications by authors named "Seger A"

Introduction: The REM Sleep Behavior Disorder (RBD) Screening Questionnaire (RBDSQ) is a widely established screening tool for detecting isolated RBD (iRBD). However, its accuracy may depend on its application context, e.g.

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Background: Isolated REM sleep behavior disorder (iRBD) is an early α-synucleinopathy often accompanied by incipient cognitive impairment. As executive dysfunctions predict earlier phenotypic conversion from iRBD to Parkinson's disease and Lewy body dementia, cognitive training focusing on executive functions could have disease-modifying effects for individuals with iRBD.

Methods: The study CogTrAiL-RBD investigates the short- and long-term effectiveness and the feasibility and underlying neural mechanisms of a cognitive training intervention for individuals with iRBD.

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Background And Objectives: Clinical heterogeneity of patients with Parkinson disease (PD) is well recognized. PD with REM sleep behavior disorder (RBD) is a more malignant phenotype with faster motor progression and higher nonmotor symptom burden. However, the neural mechanisms underlying this clinical divergence concerning imbalances in neurotransmitter systems remain elusive.

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Article Synopsis
  • Nonmotor symptoms of Parkinson's disease can show up years before movement issues, but there's no blood test to identify this early phase.
  • The study aims to find out if α-synuclein in serum-extracellular vesicles can help identify individuals at risk for developing Parkinson's and related dementia.
  • This research included a diverse group of participants with conditions like isolated rapid eye movement sleep behavior disorder (iRBD) and various control groups to test the effectiveness of this potential biomarker.
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Patients with Parkinson's disease (PD) show a broad heterogeneity in clinical presentation, and subtypes may already arise in prodromal disease stages. Isolated REM sleep behaviour disorder (iRBD) is the most specific marker of prodromal PD, but data on clinical subtyping of patients with iRBD remain scarce. Therefore, this study aimed to identify iRBD subtypes.

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Introduction: Differences in dopaminergic motor response in Parkinson's disease (PD) patients can be related to PD subtypes, and previous fMRI studies associated dopaminergic motor response with corticostriatal functional connectivity. While traditional fMRI analyses have assessed the mean connectivity between regions of interest, an important aspect driving dopaminergic response might lie in the temporal dynamics in corticostriatal connections.

Methods: This study aims to determine if altered resting-state dynamic functional network connectivity (DFC) is associated with dopaminergic motor response.

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Introduction: Dysarthria is highly prevalent in patients with Parkinson's disease (PD) and speech changes have already been detected in patients with prodromal PD on the acoustic level. However, the present study directly tracks underlying articulatory movements with electromagnetic articulography to investigate early speech alterations on the kinematic level in isolated REM sleep behavior disorder (iRBD) and compares them to PD and control speakers.

Methods: Kinematic data of 23 control speakers, 22 speakers with iRBD, and 23 speakers with PD were collected.

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The aim of this work is to quantify the metabolic profile of the human putamen in vivo in a cohort of elderly subjects using single-voxel proton magnetic resonance spectroscopy. To obtain metabolite concentrations specific to the putamen, we investigated a correction method previously proposed to account for the tissue composition of the volume of interest. We compared the method with the conventional approach, which a priori assumes equal metabolite concentrations in GM and WM.

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Seed amplification assays (SAA) are becoming commonly used in synucleinopathies to detect α-synuclein aggregates. Studies in Parkinson's disease (PD) and isolated REM-sleep behavior disorder (iRBD) have shown a considerably lower sensitivity in the olfactory epithelium than in CSF or skin. To get an insight into α-synuclein (α-syn) distribution within the nervous system and reasons for low sensitivity, we compared SAA assessment of nasal brushings and skin biopsies in PD (n = 27) and iRBD patients (n = 18) and unaffected controls (n = 30).

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Background: Lung cancer is the second leading cause of death in the United States. Lung cancer is often diagnosed in its late stage leading to a poor prognosis. Lung nodules are often described as indeterminate from CT scans resulting in lung biopsies that are invasive and may lead to complications.

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Background: Isolated rapid eye movement (REM) sleep behavior disorder (iRBD) cohorts have provided insights into the earliest neurodegenerative processes in α-synucleinopathies. Even though polysomnography (PSG) remains the gold standard for diagnosis, an accurate questionnaire-based algorithm to identify eligible subjects could facilitate efficient recruitment in research.

Objective: This study aimed to optimize the identification of subjects with iRBD from the general population.

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Background And Purpose: Cognitive decline is a frequent and debilitating non-motor symptom for patients with Parkinson's disease (PD). Metabolic alterations in the occipital cortex during visual processing may serve as a biomarker for cognitive decline in patients with PD.

Methods: Sixteen patients with PD (Unified Parkinson's Disease Rating Scale Part 3, OFF, 38.

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Neuroblastoma is a childhood cancer derived from the sympathetic nervous system. High-risk neuroblastoma patients have a poor overall survival and account for ~15% of childhood cancer deaths. There is thus a need for clinically relevant and authentic models of neuroblastoma that closely resemble the human disease to further interrogate underlying mechanisms and to develop novel therapeutic strategies.

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Background: Skin biopsy is a potential tool for the premortem confirmation of an α-synucleinopathy.

Objective: The aim was to assess the aggregation assay real-time quaking-induced conversion (RT-QuIC) of skin biopsy lysates to confirm isolated rapid eye movement sleep behavior disorder (iRBD) as an α-synucleinopathy.

Methods: Skin biopsies of patients with iRBD, Parkinson's disease (PD), and controls were analyzed using RT-QuIC and immunohistochemical detection of phospho-α-synuclein.

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Misfolded and aggregated α-synuclein is a neuropathological hallmark of Parkinson's disease (PD). Thus, α-synuclein aggregates are regarded as a biomarker for the development of diagnostic assays. Quantification of α-synuclein aggregates in body fluids is challenging, and requires highly sensitive and specific assays.

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REM sleep without atonia (RSWA) is a key feature for the diagnosis of rapid eye movement (REM) sleep behaviour disorder (RBD). We introduce RBDtector, a novel open-source software to score RSWA according to established SINBAR visual scoring criteria. We assessed muscle activity of the mentalis, flexor digitorum superficialis (FDS), and anterior tibialis (AT) muscles.

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Chemotherapy resistance and relapses are common in high-risk neuroblastoma (NB). Here, we developed a clinically relevant in vivo treatment protocol mimicking the first-line five-chemotherapy treatment regimen of high-risk NB and applied this protocol to mice with -amplified NB patient-derived xenografts (PDXs). Genomic and transcriptomic analyses were used to reveal NB chemoresistance mechanisms.

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Background: Although sleep disturbances are highly prevalent in patients with Parkinson's disease, sleep macroarchitecture metrics show only minor changes.

Objective: To assess alterations of the cyclic alternating pattern (CAP) as a critical feature of sleep microarchitecture in patients with prodromal, recent, and established Parkinson's disease.

Methods: We evaluated overnight polysomnography for classic sleep macroarchitecture and CAP metrics in 68 patients at various disease stages and compared results to 22 age- and sex-matched controls.

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Procedural learning is a vital brain function that allows us to acquire motor skills during development or re-learn them after lesions affecting the motor system. Procedural learning can be improved by feedback of different valence, e.g.

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Mitigation of fish-killing algal toxins by clay minerals offers great promise as an emergency strategy for fish farms threatened by harmful algal blooms, but its efficiency is highly clay and algal species (i.e. ichthyotoxin) specific.

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Previous studies have reported substantial involvement of the noradrenergic system in Parkinson's disease. Neuromelanin-sensitive MRI sequences and PET tracers have become available to visualize the cell bodies in the locus coeruleus and the density of noradrenergic terminal transporters. Combining these methods, we investigated the relationship of neurodegeneration in these distinct compartments in Parkinson's disease.

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Background: Motor response to dopaminergic therapy is a characteristic of patients with Parkinson's disease (PD). Whether nondopaminergic neurotransmitters contribute to treatment response is uncertain.

Objectives: The aim of this study is to determine whether putaminal y-aminobutyric acid (GABA) levels are associated with dopaminergic motor response.

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Background: Gait disturbances and balance remain challenging issues in Parkinsonian patients (PD) with deep brain stimulation (DBS). Short pulse deep brain stimulation (spDBS) increases the therapeutic window in PD patients, yet the effect on gait and postural symptoms remains unknown.

Objective: We assessed the efficacy of spDBS compared to conventional DBS (cDBS) within the subthalamic nucleus (STN) on Parkinsonian gait.

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Study Objectives: Parkinson's disease (PD) commonly involves degeneration of sleep-wake regulating brainstem nuclei; likewise, sleep-wake disturbances are highly prevalent in PD patients. As polysomnography macroparameters typically show only minor changes in PD, we investigated sleep microstructure, particularly cyclic alternating pattern (CAP), and its relation to alterations of the noradrenergic system in these patients.

Methods: We analyzed 27 PD patients and 13 healthy control (HC) subjects who underwent overnight polysomnography and 11C-MeNER positron emission tomography for evaluation of noradrenaline transporter density.

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Lobster species can accumulate paralytic shellfish toxins (PST) in their hepatopancreas following the consumption of toxic prey. The Southern Rock Lobster (SRL), , industry in Tasmania, Australia, and New Zealand, collectively valued at AUD 365 M, actively manages PST risk based on toxin monitoring of lobsters in coastal waters. The SRL supply chain predominantly provides live lobsters, which includes wet holding in fishing vessels, sea-cages, or processing facilities for periods of up to several months.

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