Impact of Phosphorylation on the Physiological Form of Human alpha-Synuclein in Aqueous Solution.

Serine 129 can be phosphorylated in pathological inclusions formed by the intrinsically disordered protein human α-synuclein (AS), a key player in Parkinson's disease and other synucleinopathies. Here, molecular simulations provide insight into the structural ensemble of phosphorylated AS. The simulations allow us to suggest that phosphorylation significantly impacts the structural content of the physiological AS conformational ensemble in aqueous solution, as the phosphate group is mostly solvated. The hydrophobic region of AS contains ß-hairpin structures, which may increase the propensity of the protein to undergo amyloid formation, as seen in the nonphysiological (nonacetylated) form of the protein in a recent molecular simulation study. Our findings are consistent with existing experimental data with the caveat of the observed limitations of the force field for the phosphorylated moiety.

Pre-stroke Functional Status in Patients Undergoing Mechanical Thrombectomy: How Relevant Are False Estimations in the Emergency Setting?

PURPOSE: The modified Rankin scale (mRS) is frequently used in the emergency setting to estimate pre-stroke functional status in stroke patients who are candidates to acute revascularization therapies (ps-mRS). We aimed to describe the agreement between pre-stroke mRS evaluated in the emergency department (ED-ps-mRS) and pre-stroke mRS evaluated comprehensively post-admission (PA-ps-mRS). METHODS: Retrospective study of consecutive ischemic stroke patients undergoing mechanical thrombectomy, with available ED-ps-mRS and PA-ps-mRS. ED-ps-mRS was evaluated by the treating neurologist and documented in the emergency stroke treatment protocol. PA-ps-mRS was retrospectively evaluated with information registered in the clinical record. Collection of baseline characteristics and 3­month outcomes. Patients with ED-overestimated pre-stroke functional status (ED ps-mRS ≤ 2 and PA-ps-mRS ≥ 3) were compared to correct low and high ED-ps-mRS groups. RESULTS: We included 409 patients (median age 77 years, 50% female, median NIHSS 14). Concordance of dichotomized ED-ps-mRS and PA-ps-mRS (0-2 vs. 3-5) was found in 81.4% (Cohen's kappa = 0.476, p < 0.001). ED-overestimated pre-stroke functional status was found in 69 patients (17%). Patients with ED-overestimated pre-stroke functional status were older (p < 0.001), more frequently presented diabetes (p < 0.001), previous stroke (p = 0.014) and less frequently presented 3­month functional independence (p < 0.001) compared to patients with correct low ED-ps-mRS. No differences in pre-stroke baseline characteristics between overestimated and correct high ED-ps-mRS was found. CONCLUSION: Disagreement between dichotomized ED-ps-mRS and PA-ps-mRS (0-2 vs. 3-5) occurred in 1/5 of patients. Overestimation of pre-stroke functional status may falsely reduce the expected proportion of patients achieving favourable 3­month functional outcomes.

Blood-Based Frailty Index in Patients with Acute Ischemic Stroke Undergoing Endovascular Treatment.

INTRODUCTION: Frailty is a syndrome depicting the vulnerability of multiple physiological systems to stressors. Frailty measures, such as Hospital Frailty Risk Score (HFRS), can be used to identify frailty and predict outcomes more reliably. Our aim was to analyze a blood-based frailty index (FI-B) at admission for prediction outcomes of patients with acute ischemic stroke (AIS) undergoing endovascular treatment (EVT). METHODS: We conducted a retrospective study of consecutive AIS patients undergoing EVT in a single tertiary center during a period of 5 years. A set of eighteen blood parameters at admission were collected and nine of these were utilized to calculate FI-B. We analyzed the relationship between FI-B and HFRS. We examined the baseline characteristics of the study population based on FI-B-tertiles. Multivariable regression models were employed to ascertain the association between FI-B and in-hospital mortality, 3-month mortality and 3-month functional outcome. RESULTS: The final study population comprised 489 patients, with a median age of 75.6 years, 49.5% of patients were male. The FI-B exhibited a weak positive correlation with HFRS (rho = 0.113, p = 0.016). Patients in higher FI-B-tertiles were older and more frequently presented with pre-stroke functional dependence and comorbidities. Moreover, an increasing FI-B was independently associated with increased likelihood of in-hospital mortality (adjusted odds ratio [aOR] = 1.29, 95% confidence interval [95% CI] = 1.14-1.47), 3-month mortality (aOR = 1.26, 95% CI = 1.11-1.43), and of increasing 3-month functional disability measured by utility-weighted modified Rankin Scale (common aOR = 0.84, 95% CI = 0.76-0.93). CONCLUSION: A frailty index based on blood values at admission was able to identify frailty in AIS patients undergoing EVT and was an independent predictor of short- and medium-term outcome after stroke.

Mid- and late-life lifestyle activities as main drivers of general and domain-specific cognitive reserve in individuals with Parkinson's disease: cross-sectional and longitudinal evidence from the LANDSCAPE study.

BACKGROUND: Cognitive reserve (CR) is considered a protective factor for cognitive function and may explain interindividual differences of cognitive performance given similar levels of neurodegeneration, e.g., in Alzheimer´s disease. Recent evidence suggests that CR is also relevant in Parkinson's disease (PD). OBJECTIVE: We aimed to explore the role of life-stage specific CR for overall cognition and specific cognitive domains cross-sectionally and longitudinally in PD. METHODS: The cross-sectional analysis with data from the DEMPARK/LANDSCAPE study included 81 individuals without cognitive impairment (PD-N) and 87 individuals with mild cognitive impairment (PD-MCI). Longitudinal data covered 4 years with over 500 observations. CR was operationalized with the Lifetime of Experiences Questionnaire (LEQ), capturing the complexity of lifestyle activities across distinct life-stages. Cognition was assessed using a comprehensive neuropsychological test battery. RESULTS: Higher LEQ scores, particularly from mid- and late-life, were observed in PD-N compared to PD-MCI [F(1,153) = 4.609, p = .033, ηp2 = 0.029]. They were significantly associated with better cognitive performance (0.200 ≤ ß ≤ 0.292). Longitudinally, linear mixed effect models (0.236 ≤ marginal R2 ≤ 0.441) revealed that LEQ scores were positively related to cognitive performance independent of time. However, the decline in overall cognition and memory over time was slightly more pronounced with higher LEQ scores. CONCLUSIONS: This study emphasizes the association between complex lifestyle activities and cognition in PD. Data indicate that while CR might be related to a delay of cognitive decline, individuals with high CR may experience a more pronounced drop in overall cognition and memory. Future studies will have to replicate these findings, particularly regarding domain-specific effects and considering reverse causal mechanisms.

Deep abdominal breathing reduces heart rate and symptoms during orthostatic challenge in patients with postural orthostatic tachycardia syndrome.

BACKGROUND AND PURPOSE: This study investigated the effects of deep abdominal breathing on cardiovascular parameters and symptoms in patients with postural orthostatic tachycardia syndrome (POTS) during head-up tilt-table (HUT) challenge. METHODS: Thirty POTS patients completed two consecutive rounds of 10-min HUT in a crossover design. One round was HUT without intervention, and one round combined the HUT with deep breathing at a rate of 6 breaths/min. Cardiovascular parameters, including mean blood pressure and maximum and mean heart rate (HR), were measured supine and standing. Symptoms were assessed using the Vanderbilt Orthostatic Symptom Score (VOSS). RESULTS: During the breathing technique, the mean HR increase was -7.35 bpm (95% confidence interval [CI] = -11.71 to -2.98), and the maximum HR increase was -6.27 bpm (95% CI = -11.85 to -0.68, p = 0.041), significantly lower compared to normal breathing. Additionally, improvements were observed in all absolute cardiovascular parameters during standing, with VOSS symptoms simultaneously and significantly decreasing by -5.38 (95% CI = -10.43 to -0.36). CONCLUSIONS: Slow deep abdominal breathing can act as a simple technique to reduce the standing HR increase upon HUT in patients with POTS. This suggests that modulation of the cardiopulmonary neurocircuits and the respiratory pump may reduce HR increase and symptoms in patients with POTS. The findings of this study highlight the use of a safe, zero-cost, and simple behavioral tool to suggest to POTS patients for symptom relief apart from standard treatment. The observed improvements in cardiovascular parameters and symptoms offer a promising therapeutic approach for patients in times of inadequate treatment options.

Non-hemorrhagic imaging markers of cerebral amyloid angiopathy in memory clinic patients.

INTRODUCTION: The Boston criteria v2.0 for cerebral amyloid angiopathy (CAA) incorporated non-hemorrhagic imaging markers. Their prevalence and significance in patients with cognitive impairment remain uncertain. METHODS: We studied 622 memory clinic patients with available magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) biomarkers. Two raters assessed non-hemorrhagic markers, and we explored their association with clinical characteristics through multivariate analyses. RESULTS: Most patients had mild cognitive impairment; median age was 71 years and 50% were female. Using the v2.0 criteria, possible or probable CAA increased from 75 to 383 patients. Sixty-eight percent of the sample had non-hemorrhagic CAA markers, which were independently associated with age (odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.01-1.07), female sex (OR = 1.68, 95% CI = 1.11-2.54), and hemorrhagic CAA markers (OR = 2.11, 95% CI = 1.02-4.35). DISCUSSION: Two-thirds of patients from a memory clinic cohort had non-hemorrhagic CAA markers, increasing the number of patients meeting the v2.0 CAA criteria. Longitudinal approaches should explore the implications of these markers, particularly the hemorrhagic risk in this population. HIGHLIGHTS: The updated Boston criteria for cerebral amyloid angiopathy (CAA) now include non-hemorrhagic markers. The prevalence of non-hemorrhagic CAA markers in memory clinic patients is unknown. Two-thirds of patients in our memory clinic presented non-hemorrhagic CAA markers. The presence of these markers was associated with age, female sex, and hemorrhagic CAA markers. The hemorrhagic risk of patients presenting these type of markers remains unclear.

Swallowing muscle mass contributes to post-stroke dysphagia in ischemic stroke patients undergoing mechanical thrombectomy.

BACKGROUND: Neurogenic dysphagia is a frequent complication of stroke and is associated with aspiration pneumonia and poor outcomes. Although ischaemic lesion location and size are major determinants of the presence and severity of post-stroke dysphagia, little is known about the contribution of other acute stroke-unrelated factors. We aimed to analyse the impact of swallowing and non-swallowing muscles measurements on swallowing function after large vessel occlusion stroke. METHODS: This retrospective study was based on a prospective registry of consecutive ischaemic stroke patients. Patients who underwent mechanical thrombectomy between July 2021 and June 2022 and received a flexible endoscopic evaluation of swallowing (FEES) within 5 days after admission were included. Demographic, anthropometric, clinical, and imaging data were collected from the registry. The cross-sectional areas (CSA) of selected swallowing muscles (as a surrogate marker for swallowing muscle mass) and of cervical non-swallowing muscles were measured in computed tomography. Skeletal muscle index (SMI) was calculated and used as a surrogate marker for whole body muscle mass. FEES parameters, namely, Functional Oral Intake Scale (FOIS, as a surrogate marker for dysphagia presence and severity), penetration aspiration scale, and the presence of moderate-to-severe pharyngeal residues were collected from the clinical records. Univariate and multivariate ordinal and logistic regression analyses were performed to analyse if total CSA of swallowing muscles and SMI were associated with FEES parameters. RESULTS: The final study population consisted of 137 patients, 59 were female (43.1%), median age was 74 years (interquartile range 62-83), median baseline National Institutes of Health Stroke Scale score was 12 (interquartile range 7-16), 16 patients had a vertebrobasilar occlusion (11.7%), and successful recanalization was achieved in 127 patients (92.7%). Both total CSA of swallowing muscles and SMI were significantly correlated with age (rho = -0.391, P < 0.001 and rho = -0.525, P < 0.001, respectively). Total CSA of the swallowing muscles was independently associated with FOIS (common adjusted odds ratio = 1.08, 95% confidence interval = 1.01-1.16, P = 0.029), and with the presence of moderate-to-severe pharyngeal residues for puree consistencies (adjusted odds ratio = 0.90, 95% confidence interval = 0.81-0.99, P = 0.036). We found no independent association of SMI with any of the FEES parameters. CONCLUSIONS: Baseline swallowing muscle mass contributes to the pathophysiology of post-stroke dysphagia. Decreasing swallowing muscle mass is independently associated with increasing severity of early post-stroke dysphagia and with increased likelihood of moderate-to-severe pharyngeal residues.

Success rates of intensive aphasia therapy: real-world data from 448 patients between 2003 and 2020.

BACKGROUND: Aphasia is a devastating consequence after stroke, affecting millions of patients each year. Studies have shown that intensive speech and language therapy (SLT) is effective in the chronic phase of aphasia. Leveraging a large single-center cohort of persons with aphasia (PWA) including patients also in the subacute phase, we assessed treatment effects of intensive aphasia therapy in a real-world setting. METHODS: Data were collected at the Aachen aphasia ward in Germany between 2003 and 2020. Immediate treatment responses across different language domains were assessed with the Aachen Aphasia Test (AAT) using single-case psychometrics, conducted before and after 6-7 weeks of intensive SLT (10 h per week, median (IQR) dosage = 68 (61-76)). We adjusted for spontaneous recovery in subacute patients. Differential treatment effects between subgroups of chronicity and predictors of therapy response were investigated. RESULTS: A total of 448 PWA were included (29% female, median (IQR) age = 54 (46-62) years, median (IQR) time post-onset = 11 (6-20) months) with 12% in the early subacute, 15% in the late subacute and 74% in the chronic phase of aphasia. The immediate responder rate was 59%. Significant improvements in all AAT subtests und subscales were observed hinting at broad effectiveness across language domains. The degree of therapy-induced improvement did not differ between the chronicity groups. Time post-onset, dosage of therapy and aphasia severity at the beginning of treatment were predictors of immediate treatment response. DISCUSSION: Intensive therapy protocols for aphasia after stroke are yielding substantial responder rates in a routine clinical setting including a wide range of patients.

Video-based analysis of the blink reflex in Parkinson's disease patients.

We developed a video-based tool to quantitatively assess the Glabellar Tap Reflex (GTR) in patients with idiopathic Parkinson's disease (iPD) as well as healthy age-matched participants. We also video-graphically assessed the effect of dopaminergic medication on the GTR in iPD patients, as well as the frequency and blinking duration of reflex and non-reflex blinks. The Glabellar Tap Reflex is a clinical sign seen in patients e.g. suffering from iPD. Reliable tools to quantify this sign are lacking. METHODS: We recorded the GTR in 11 iPD patients and 12 healthy controls (HC) with a consumer-grade camera at a framerate of at least 180 images/s. In these videos, reflex and non-reflex blinks were analyzed for blink count and blinking duration in an automated fashion. RESULTS: With our setup, the GTR can be extracted from high-framerate cameras using landmarks of the MediaPipe face algorithm. iPD patients did not habituate to the GTR; dopaminergic medication did not alter that response. iPD patients' non-reflex blinks were higher in frequency and higher in blinking duration (width at half prominence); dopaminergic medication decreased the median frequency (Before medication-HC: p < 0.001, After medication-HC: p = 0.0026) and decreased the median blinking duration (Before medication-HC: p = 0.8594, After medication-HC: p = 0.6943)-both in the direction of HC. CONCLUSION: We developed a quantitative, video-based tool to assess the GTR and other blinking-specific parameters in HC and iPD patients. Further studies could compare the video data to electromyogram (EMG) data for accuracy and comparability, as well as evaluate the specificity of the GTR in patients with other neurodegenerative disorders, in whom the GTR can also be present. SIGNIFICANCE: The video-based detection of the blinking parameters allows for unobtrusive measurement in patients, a safer and more comfortable option.

Communicative impairment and its neural correlates in Alzheimer's disease and frontotemporal dementia.

OBJECTIVE: Communication skills can deteriorate in neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal dementia (FTD); however, their clinical assessment and treatment in patient care can be challenging. In the present study, we aimed to quantify the distinctive communication resources and barriers reported by patients and their relatives in AD and FTD and associated these communicative characteristics with clinical parameters, such as the degree of cognitive impairment and atrophy in language-associated brain areas. METHODS: We assessed self-reported communication barriers and resources in 33 individuals with AD and FTD through an interview on daily-life communication, using the Aachener KOMPASS questionnaire. We correlated reported communication barriers and resources with atrophy from high-resolution 3T brain magnetic resonance imaging, neuropsychological assessment, and neurodegenerative markers from cerebrospinal fluid. RESULTS: Communicative impairment was higher in FTD compared to AD. Increased reported communication barriers in our whole sample were associated with the atrophy rate in the left middle temporal lobe, a critical site within the neuronal language network, and with depressive symptoms as well as the semantic word fluency from neuropsychological assessment. The best model for prediction of communicative impairment included the diagnosis (AD or FTD), semantic word fluency, and depressive symptoms. CONCLUSIONS: Our study demonstrates that communication barriers and resources can be successfully assessed via a structured interview based on self-report and report of patients' relatives in practice and are reflected in neuroimaging specific for AD and FTD as well as in further clinical parameters specific for these neurodegenerative diseases. This can potentially open new treatment options for clinical practice and patient care.

The functional brain connectome in isolated rapid eye movement sleep behavior disorder and Parkinson's disease.

BACKGROUND: Isolated rapid-eye-movement behavior disorder (iRBD) often precedes the development of alpha-synucleinopathies such as Parkinson's disease (PD). Magnetic resonance imaging (MRI) studies have revealed structural brain alterations in iRBD partially resembling those observed in PD. However, relatively little is known about whole-brain functional brain alterations in iRBD. Here, we characterize the functional brain connectome of iRBD compared with PD patients and healthy controls (HC) using resting-state functional MRI (rs-fMRI). METHODS: Eighteen iRBD subjects (67.3 ± 6.6 years), 18 subjects with PD (65.4 ± 5.8 years), and 39 age- and sex-matched HC (64.4 ± 9.2 years) underwent rs-fMRI at 3 T. We applied a graph theoretical approach to analyze the brain functional connectome at the global and regional levels. Data were analyzed using both frequentist and Bayesian statistics. RESULTS: Global connectivity was largely preserved in iRBD and PD individuals. In contrast, both disease groups displayed altered local connectivity mainly in the motor network, temporal cortical regions including the limbic system, and the visual system. There were some group specific alterations, and connectivity changes were pronounced in PD individuals. Overall, however, there was a good agreement of the connectome changes observed in both disease groups. CONCLUSIONS: This study provides evidence for widespread functional brain connectivity alterations in iRBD, including motor circuitry, despite normal motor function. Connectome alterations showed substantial resemblance with those observed in PD, underlining a close pathophysiological relationship of iRBD and PD.

Recommendations for optimal interdisciplinary management and healthcare settings for patients with rare neurological diseases.

BACKGROUND: In 2017, the German Academy for Rare Neurological Diseases (Deutsche Akademie für Seltene Neurologische Erkrankungen; DASNE) was founded to pave the way for an optimized personalized management of patients with rare neurological diseases (RND) in all age groups. Since then a dynamic national network for rare neurological disorders has been established comprising renowned experts in neurology, pediatric neurology, (neuro-) genetics and neuroradiology. DASNE has successfully implemented case presentations and multidisciplinary discussions both at yearly symposia and monthly virtual case conferences, as well as further educational activities covering a broad spectrum of interdisciplinary expertise associated with RND. Here, we present recommendation statements for optimized personalized management of patients with RND, which have been developed and reviewed in a structured Delphi process by a group of experts. METHODS: An interdisciplinary group of 37 RND experts comprising DASNE experts, patient representatives, as well as healthcare professionals and managers was involved in the Delphi process. First, an online collection was performed of topics considered relevant for optimal patient care by the expert group. Second, a two-step Delphi process was carried out to rank the importance of the selected topics. Small interdisciplinary working groups then drafted recommendations. In two consensus meetings and one online review round these recommendations were finally consented. RESULTS: 38 statements were consented and grouped into 11 topics: health care structure, core neurological expertise and core mission, interdisciplinary team composition, diagnostics, continuous care and therapy development, case conferences, exchange / cooperation between Centers for Rare Diseases and other healthcare partners, patient advocacy group, databases, translation and health policy. CONCLUSIONS: This German interdisciplinary Delphi expert panel developed consented recommendations for optimal care of patients with RND in a structured Delphi process. These represent a basis for further developments and adjustments in the health care system to improve care for patients with RND and their families.

Characteristic functional connectome related to Post-COVID-19 syndrome.

Post-COVID-19 syndrome is a serious complication following SARS-CoV-2 infection, characterized primarily by fatigue and cognitive complaints. Although first metabolic and structural imaging alterations in Post-COVID-19 syndrome have been identified, their functional consequences remain unknown. Thus, we explored the impact of Post-COVID-19 syndrome on the functional connectome of the brain providing a deeper understanding of pathophysiological mechanisms. In a cross-sectional observational study, resting-state functional magnetic resonance imaging data of 66 patients with Post-COVID-19 syndrome after mild infection (mean age 42.3 years, 57 female) and 57 healthy controls (mean age 42.1 years, 38 female) with a mean time of seven months after acute COVID-19 were analysed using a graph theoretical approach. Network features were quantified using measures including mean distance, nodal degree, betweenness and Katz centrality, and compared between both groups. Graph measures were correlated with clinical measures quantifying fatigue, cognitive function, affective symptoms and sleep disturbances. Alterations were mainly found in the brainstem, olfactory cortex, cingulate cortex, thalamus and cerebellum on average seven months after SARS-CoV-2 infection. Additionally, strong correlations between fatigue severity, cognitive functioning and daytime sleepiness from clinical scales and graph measures were observed. Our study confirms functional relevance of brain imaging changes in Post-COVID-19 syndrome as mediating factors for persistent symptoms and improves our pathophysiological understanding.

[Neuropathic pain as a symptom in autonomic neuropathies and other rare diseases : Small fiber neuropathy: its recognition, diagnosis, and treatment]. / Neuropathische Schmerzen als Symptom bei autonomen Neuropathien und anderen seltenen Erkrankungen : Kleinfaserneuropathie erkennen, diagnostizieren und behandeln.

BACKGROUND: Neuropathic pain is difficult to diagnose and treat. Small fiber neuropathy (SFN) flies under the radar of nerve conduction studies. OBJECTIVES: The importance of a structured patient history and physical examination in the context of neuropathic pain is emphasized. Describing SFN as an important cause, the authors consider rare but partially treatable differential diagnoses. They conclude that autonomic symptoms are frequently associated, often presenting with diverse symptoms. METHODS: A selective literature research to present SFN symptoms as well as differential diagnostic and therapeutic steps in the context of SFN and rare diseases focusing on the autonomic nervous system. RESULTS: Neuropathic pain significantly reduces quality of life. To shorten the time until diagnosis and to initiate therapy, the authors recommend a structured patient history including sensory plus and minus symptoms and non-specific autonomic signs. If the initial search for the cause is not successful, rare causes such as treatable transthyretin (ATTR) amyloidosis and Fabry's disease or autoimmune causes should be considered, particularly in the case of progressive and/or autonomic symptoms. CONCLUSION: The diagnosis and therapy of rare SFN requires interdisciplinary collaboration and, in many cases, a referral to specialized centers to achieve the best patient care.

Early flexible endoscopic evaluation of swallowing after mechanical thrombectomy in stroke patients.

OBJECTIVE: The aims of the study were to (1) characterize the findings of flexible endoscopic evaluation of swallowing (FEES) in stroke patients undergoing mechanical thrombectomy (MT); (2) analyse the screening performance of the Standardized Swallowing Assessment (SSA); and (3) study the impact of FEES-defined dysphagia on 3-month outcomes. METHODS: This single-centre study was based on a local registry of consecutive acute ischaemic stroke patients undergoing MT during a 1-year period. Patients received FEES within 5 days of admission regardless of the result of dysphagia screening. We compared baseline demographic and clinical characteristics of patients with and without FEES-defined dysphagia. We collected 3-month modified Rankin Scale (mRS) and individual index values of the European Quality of Life 5 Dimensions (EQ-5D-iv). Using univariable and multivariable regression analyses we predicted 3-month outcomes for presence of dysphagia and for FEES-defined dysphagia severity. RESULTS: We included 137 patients with a median age of 74 years, 43.1% were female, median NIHSS was 12 and successful recanalization was achieved in 92.7%. Stroke-associated pneumonia occurred in 8% of patients. FEES-defined dysphagia occurred in 81% of patients. Sensitivity of the SSA as a dysphagia screening was 67%. Presence of dysphagia and increasing severity of dysphagia were independently associated with increasing 3-month mRS score. Increasing dysphagia severity dysphagia was independently associated with lower EQ-5D-iv. INTERPRETATION: Early FEES-defined dysphagia occurs in four in every five patients undergoing MT. SSA has a suboptimal dysphagia screening performance. Presence of dysphagia and increasing dysphagia severity predict worse functional outcome and worse health-related quality-of-life.

Unexpected Single-Ligand Occupancy and Negative Cooperativity in the SARS-CoV-2 Main Protease.

Many homodimeric enzymes tune their functions by exploiting either negative or positive cooperativity between subunits. In the SARS-CoV-2 Main protease (Mpro) homodimer, the latter has been suggested by symmetry in most of the 500 reported protease/ligand complex structures solved by macromolecular crystallography (MX). Here we apply the latter to both covalent and noncovalent ligands in complex with Mpro. Strikingly, our experiments show that the occupation of both active sites of the dimer originates from an excess of ligands. Indeed, cocrystals obtained using a 1:1 ligand/protomer stoichiometry lead to single occupation only. The empty binding site exhibits a catalytically inactive geometry in solution, as suggested by molecular dynamics simulations. Thus, Mpro operates through negative cooperativity with the asymmetric activity of the catalytic sites. This allows it to function with a wide range of substrate concentrations, making it resistant to saturation and potentially difficult to shut down, all properties advantageous for the virus' adaptability and resistance.

Predictors of Survival in Friedreich's Ataxia: A Prospective Cohort Study.

BACKGROUND: Friedreich's ataxia (FA) is a rare multisystemic disorder which can cause premature death. OBJECTIVES: To investigate predictors of survival in FA. METHODS: Within a prospective registry established by the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS; ClinicalTrials.gov identifier NCT02069509) we enrolled genetically confirmed FA patients at 11 tertiary centers and followed them in yearly intervals. We investigated overall survival applying the Kaplan-Meier method, life tables, and log-rank test. We explored prognostic factors applying Cox proportional hazards regression and subsequently built a risk score which was assessed for discrimination and calibration performance. RESULTS: Between September 2010 and March 2017, we enrolled 631 FA patients. Median age at inclusion was 31 (range, 6-76) years. Until December 2022, 44 patients died and 119 terminated the study for other reasons. The 10-year cumulative survival rate was 87%. In a multivariable analysis, the disability stage (hazard ratio [HR] 1.51, 95% CI 1.08-2.12, P = 0.02), history of arrhythmic disorder (HR 2.93, 95% CI 1.34-6.39, P = 0.007), and diabetes mellitus (HR 2.31, 95% CI 1.05-5.10, P = 0.04) were independent predictors of survival. GAA repeat lengths did not improve the survival model. A risk score built on the previously described factors plus the presence of left ventricular systolic dysfunction at echocardiography enabled identification of four trajectories to prognosticate up to 10-year survival (log-rank test P < 0.001). CONCLUSIONS: Arrhythmias, progressive neurological disability, and diabetes mellitus influence the overall survival in FA. We built a survival prognostic score which identifies patients meriting closer surveillance and who may benefit from early invasive cardiac monitoring and therapy. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Contributions of Vascular Burden and Amyloid Abnormality to Cognitive Decline in Memory Clinic Patients.

Background: Alzheimer's disease pathology and vascular burden are highly prevalent and often co-occur in elderly. It remains unclear how both relate to cognitive decline. Objective: To investigate whether amyloid abnormality and vascular burden synergistically contribute to cognitive decline in a memory clinic population. Methods: We included 227 patients from Maastricht and Aachen memory clinics. Amyloid abnormality (A+) was defined by CSF Aß42 using data-driven cut-offs. Vascular burden (V+) was defined as having moderate to severe white matter hyperintensities, or any microbleeds, macrohemorrhage or infarcts on MRI. Longitudinal change in global cognition, memory, processing speed, executive functioning, and verbal fluency was analysed across the A-V-, A-V+, A+V-, A+V+ groups by linear mixed models. Additionally, individual MRI measures, vascular risk and vascular disease were used as V definitions. Results: At baseline, the A+V+ group scored worse on global cognition and verbal fluency compared to all other groups, and showed worse memory compared to A-V+ and A-V- groups. Over time (mean 2.7+ - 1.5 years), A+V+ and A+V- groups showed faster global cognition decline than A-V+ and A-V- groups. Only the A+V- group showed decline on memory and verbal fluency. The A-V+ group did not differ from the A-V- group. Individual MRI vascular measures only indicated an independent association of microbleeds with executive functioning decline. Findings were similar using other V definitions. Conclusions: Our study demonstrates that amyloid abnormality predicts cognitive decline independent from vascular burden in a memory clinic population. Vascular burden shows a minor contribution to cognitive decline in these patients. This has important prognostic implications.

Factors associated with the laterality of Cardio-Embolic stroke.

OBJECTIVE: Understanding the lateralization factors, including the anatomic and hemodynamic mechanisms, is essential for diagnosing cardio-embolic stroke. This study aims to investigate the elements, for the first time together, that could affect the laterality of stroke. METHODS: We performed a monocentric retrospective case-control study based on prospective registries of acute ischemic stroke patients in the comprehensive stroke center of the RWTH University hospital of Aachen for three years (June 2018-June 2021). We enrolled 222 patients with cardioembolic stroke (136 left stroke and 86 right stroke) admitted for first-ever acute ischemic stroke with unilateral large vessel occlusion of the anterior circulation. The peak systolic velocity (PSV) asymmetry of middle cerebral artery (MCA) was assessed by doppler as well as internal carotid artery (ICA) angle, aortic arch (AA) branching pattern and anatomy were assessed by CT-Angiography. RESULTS: We found that the increasing left ICA angle (p = 0.047), presence of bovine type AA anatomy (p = 0.041) as well as slow PSV of the right MCA with a value of >15% than left (p = 0.005) were the predictors for left stroke lateralization, while the latter was an independent predictor for the left stroke (OR=3.341 [1.415-7.887]). Inter-Rater Reliability ranged from moderate to perfect agreement. CONCLUSION: The predictors for left stroke lateralization include the higher values of left ICA angle, presence of the bovine type AA and the slow right MCA PSV.