Evaluation of Cerebrospinal Fluid α-Synuclein Seed Amplification Assay in Progressive Supranuclear Palsy and Corticobasal Syndrome.

BACKGROUND: Seed amplification assay (SAA) testing has been developed as a biomarker for the diagnosis of α-synuclein-related neurodegenerative disorders. OBJECTIVE: The objective of this study was to assess the rate of α-synuclein SAA positivity in progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) and to analyze clinical and pathological features of SAA-positive and -negative cases. METHODS: A total of 96 cerebrospinal fluid samples from clinically diagnosed PSP (n = 59) and CBS (n = 37) cases were analyzed using α-synuclein SAA. RESULTS: Six of 59 (10.2%) PSP cases were α-synuclein SAA positive, including one case who was MSA-type positive. An exploratory analysis showed that PSP cases who were Parkinson's disease-type positive were older and had a shorter disease duration compared with SAA-negative cases. In contrast, 11 of 37 (29.7%) CBS cases were α-synuclein SAA positive, including two cases who were MSA-type positive. CONCLUSIONS: Our results suggest that α-synuclein seeds can be detected in PSP and CBS using a cerebrospinal fluid α-synuclein SAA, and in PSP this may impact on clinical course. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Frequency and outcomes of gastrostomy insertion in a longitudinal cohort study of atypical parkinsonism.

BACKGROUND: Multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) show a high prevalence and rapid progression of dysphagia, which is associated with reduced survival. Despite this, the evidence base for gastrostomy is poor, and the optimal frequency and outcomes of this intervention are not known. We aimed to characterise the prevalence and outcomes of gastrostomy in patients with these three atypical parkinsonian disorders. METHOD: We analysed data from the natural history and longitudinal cohorts of the PROSPECT-M-UK study with up to 60 months of follow-up from baseline. Survival post-gastrostomy was analysed using Kaplan-Meier survival curves. RESULTS: In a total of 339 patients (mean age at symptom onset 63.3 years, mean symptom duration at baseline 4.6 years), dysphagia was present in >50% across all disease groups at baseline and showed rapid progression during follow-up. Gastrostomy was recorded as recommended in 44 (13%) and performed in 21 (6.2%; MSA 7, PSP 11, CBS 3) of the total study population. Median survival post-gastrostomy was 24 months compared with 12 months where gastrostomy was recommended but not done (p = 0.008). However, this was not significant when correcting for age and duration of symptoms at the time of procedure or recommendation. CONCLUSIONS: Gastrostomy was performed relatively infrequently in this cohort despite the high prevalence of dysphagia. Survival post-gastrostomy was longer than previously reported, but further data on other outcomes and clinician and patient perspectives would help to guide use of this intervention in MSA, PSP and CBS.

Progression of atypical parkinsonian syndromes: PROSPECT-M-UK study implications for clinical trials.

The advent of clinical trials of disease-modifying agents for neurodegenerative disease highlights the need for evidence-based end point selection. Here we report the longitudinal PROSPECT-M-UK study of progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), multiple system atrophy (MSA) and related disorders, to compare candidate clinical trial end points. In this multicentre UK study, participants were assessed with serial questionnaires, motor examination, neuropsychiatric and MRI assessments at baseline, 6 and 12 months. Participants were classified by diagnosis at baseline and study end, into Richardson syndrome, PSP-subcortical (PSP-parkinsonism and progressive gait freezing subtypes), PSP-cortical (PSP-frontal, PSP-speech and language and PSP-CBS subtypes), MSA-parkinsonism, MSA-cerebellar, CBS with and without evidence of Alzheimer's disease pathology and indeterminate syndromes. We calculated annual rate of change, with linear mixed modelling and sample sizes for clinical trials of disease-modifying agents, according to group and assessment type. Two hundred forty-three people were recruited [117 PSP, 68 CBS, 42 MSA and 16 indeterminate; 138 (56.8%) male; age at recruitment 68.7 ± 8.61 years]. One hundred and fifty-nine completed the 6-month assessment (82 PSP, 27 CBS, 40 MSA and 10 indeterminate) and 153 completed the 12-month assessment (80 PSP, 29 CBS, 35 MSA and nine indeterminate). Questionnaire, motor examination, neuropsychiatric and neuroimaging measures declined in all groups, with differences in longitudinal change between groups. Neuroimaging metrics would enable lower sample sizes to achieve equivalent power for clinical trials than cognitive and functional measures, often achieving N < 100 required for 1-year two-arm trials (with 80% power to detect 50% slowing). However, optimal outcome measures were disease-specific. In conclusion, phenotypic variance within PSP, CBS and MSA is a major challenge to clinical trial design. Our findings provide an evidence base for selection of clinical trial end points, from potential functional, cognitive, clinical or neuroimaging measures of disease progression.

Network connectivity and structural correlates of survival in progressive supranuclear palsy and corticobasal syndrome.

There is a pressing need to understand the factors that predict prognosis in progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), with high heterogeneity over the poor average survival. We test the hypothesis that the magnitude and distribution of connectivity changes in PSP and CBS predict the rate of progression and survival time, using datasets from the Cambridge Centre for Parkinson-plus and the UK National PSP Research Network (PROSPECT-MR). Resting-state functional MRI images were available from 146 participants with PSP, 82 participants with CBS, and 90 healthy controls. Large-scale networks were identified through independent component analyses, with correlations taken between component time series. Independent component analysis was also used to select between-network connectivity components to compare with baseline clinical severity, longitudinal rate of change in severity, and survival. Transdiagnostic survival predictors were identified using partial least squares regression for Cox models, with connectivity compared to patients' demographics, structural imaging, and clinical scores using five-fold cross-validation. In PSP and CBS, between-network connectivity components were identified that differed from controls, were associated with disease severity, and were related to survival and rate of change in clinical severity. A transdiagnostic component predicted survival beyond demographic and motion metrics but with lower accuracy than an optimal model that included the clinical and structural imaging measures. Cortical atrophy enhanced the connectivity changes that were most predictive of survival. Between-network connectivity is associated with variability in prognosis in PSP and CBS but does not improve predictive accuracy beyond clinical and structural imaging metrics.

Neurofilament light levels predict clinical progression and death in multiple system atrophy.

Disease-modifying treatments are currently being trialled in multiple system atrophy. Approaches based solely on clinical measures are challenged by heterogeneity of phenotype and pathogenic complexity. Neurofilament light chain protein has been explored as a reliable biomarker in several neurodegenerative disorders but data on multiple system atrophy have been limited. Therefore, neurofilament light chain is not yet routinely used as an outcome measure in multiple system atrophy. We aimed to comprehensively investigate the role and dynamics of neurofilament light chain in multiple system atrophy combined with cross-sectional and longitudinal clinical and imaging scales and for subject trial selection. In this cohort study, we recruited cross-sectional and longitudinal cases in a multicentre European set-up. Plasma and CSF neurofilament light chain concentrations were measured at baseline from 212 multiple system atrophy cases, annually for a mean period of 2 years in 44 multiple system atrophy patients in conjunction with clinical, neuropsychological and MRI brain assessments. Baseline neurofilament light chain characteristics were compared between groups. Cox regression was used to assess survival; receiver operating characteristic analysis to assess the ability of neurofilament light chain to distinguish between multiple system atrophy patients and healthy controls. Multivariate linear mixed-effects models were used to analyse longitudinal neurofilament light chain changes and correlated with clinical and imaging parameters. Polynomial models were used to determine the differential trajectories of neurofilament light chain in multiple system atrophy. We estimated sample sizes for trials aiming to decrease neurofilament light chain levels. We show that in multiple system atrophy, baseline plasma neurofilament light chain levels were better predictors of clinical progression, survival and degree of brain atrophy than the neurofilament light chain rate of change. Comparative analysis of multiple system atrophy progression over the course of disease, using plasma neurofilament light chain and clinical rating scales, indicated that neurofilament light chain levels rise as the motor symptoms progress, followed by deceleration in advanced stages. Sample size prediction suggested that significantly lower trial participant numbers would be needed to demonstrate treatment effects when incorporating plasma neurofilament light chain values into multiple system atrophy clinical trials in comparison to clinical measures alone. In conclusion, neurofilament light chain correlates with clinical disease severity, progression and prognosis in multiple system atrophy. Combined with clinical and imaging analysis, neurofilament light chain can inform patient stratification and serve as a reliable biomarker of treatment response in future multiple system atrophy trials of putative disease-modifying agents.

Potential of Non-Coding RNA as Biomarkers for Progressive Supranuclear Palsy.

Objective markers for the neurodegenerative disorder progressive supranuclear palsy (PSP) are needed to provide a timely diagnosis with greater certainty. Non-coding RNA (ncRNA), including microRNA, piwi-interacting RNA, and transfer RNA, are good candidate markers in other neurodegenerative diseases, but have not been investigated in PSP. Therefore, as proof of principle, we sought to identify whether they were dysregulated in matched serum and cerebrospinal fluid (CSF) samples of patients with PSP. Small RNA-seq was undertaken on serum and CSF samples from healthy controls (n = 20) and patients with PSP (n = 31) in two cohorts, with reverse transcription-quantitative PCR (RT-qPCR) to confirm their dysregulation. Using RT-qPCR, we found in serum significant down-regulation in hsa-miR-92a-3p, hsa-miR-626, hsa-piR-31068, and tRNA-ValCAC. In CSF, both hsa-let-7a-5p and hsa-piR-31068 showed significant up-regulation, consistent with their changes observed in the RNA-seq results. Interestingly, we saw no correlation in the expression of hsa-piR-31068 within our matched serum and CSF samples, suggesting there is no common dysregulatory mechanism between the two biofluids. While these changes were in a small cohort of samples, we have provided novel evidence that ncRNA in biofluids could be possible diagnostic biomarkers for PSP and further work will help to expand this potential.

Proximity extension assay testing reveals novel diagnostic biomarkers of atypical parkinsonian syndromes.

OBJECTIVE: The high degree of clinical overlap between atypical parkinsonian syndromes (APS) and Parkinson's disease (PD) makes diagnosis challenging. We aimed to identify novel diagnostic protein biomarkers of APS using multiplex proximity extension assay (PEA) testing. METHODS: Cerebrospinal fluid (CSF) samples from two independent cohorts, each consisting of APS and PD cases, and controls, were analysed for neurofilament light chain (NF-L) and Olink Neurology and Inflammation PEA biomarker panels. Whole-cohort comparisons of biomarker concentrations were made between APS (n=114), PD (n=37) and control (n=34) groups using logistic regression analyses that included gender, age and disease duration as covariates. RESULTS: APS versus controls analyses revealed 11 CSF markers with significantly different levels in cases and controls (p<0.002). Four of these markers also reached significance (p<0.05) in APS versus PD analyses. Disease-specific analyses revealed lower group levels of FGF-5, FGF-19 and SPOCK1 in multiple system atrophy compared with progressive supranuclear palsy and corticobasal syndrome. Receiver operating characteristic curve analyses suggested that the diagnostic accuracy of NF-L was superior to the significant PEA biomarkers in distinguishing APS, PD and controls. The biological processes regulated by the significant proteins include cell differentiation and immune cell migration. Delta and notch-like epidermal growth factor-related receptor (DNER) had the strongest effect size in APS versus controls and APS versus PD analyses. DNER is highly expressed in substantia nigra and is an activator of the NOTCH1 pathway which has been implicated in the aetiology of other neurodegenerative disorders including Alzheimer's disease. CONCLUSIONS: PEA testing has identified potential novel diagnostic biomarkers of APS.

The CRASH report: emergency management dilemmas facing acute physicians in patients with pulmonary arterial hypertension.

Treatment of acute emergencies in patients with pulmonary arterial hypertension (PAH) can be challenging. In the UK and Ireland, management of adult patients with PAH is centred in eight nationally designated pulmonary hypertension (PH) centres. However, many patients live far from these centres and physicians in local hospitals are often required to manage PAH emergencies. A committee of physicians from nationally designated PH centres identified the 'most common' emergency clinical scenarios encountered in patients with PAH. Thereafter, a review of the literature was performed centred on these specified topics and a management approach was developed based on best available evidence and expert consensus. Management protocols were developed on the following PAH emergencies: chest pain (including myocardial ischaemia), right ventricular failure, arrhythmias, sepsis, haemoptysis ('CRASH'), as well as considerations relevant to surgery, anaesthesia and pregnancy. Emergencies are not uncommon in PAH. While expertise in PAH management is essential, all physicians involved in acute care should be aware of the principles of acute management of PAH emergencies. A multidisciplinary approach is necessary, with physicians from tertiary PH centres supporting care locally and planning safe transfer of patients to PH centres when appropriate.

The reversal of pulmonary vascular remodeling through inhibition of p38 MAPK-alpha: a potential novel anti-inflammatory strategy in pulmonary hypertension.

The p38 mitogen-activated protein kinase (MAPK) system is increasingly recognized as an important inflammatory pathway in systemic vascular disease but its role in pulmonary vascular disease is unclear. Previous in vitro studies suggest p38 MAPKα is critical in the proliferation of pulmonary artery fibroblasts, an important step in the pathogenesis of pulmonary vascular remodeling (PVremod). In this study the role of the p38 MAPK pathway was investigated in both in vitro and in vivo models of pulmonary hypertension and human disease. Pharmacological inhibition of p38 MAPKα in both chronic hypoxic and monocrotaline rodent models of pulmonary hypertension prevented and reversed the pulmonary hypertensive phenotype. Furthermore, with the use of a novel and clinically available p38 MAPKα antagonist, reversal of pulmonary hypertension was obtained in both experimental models. Increased expression of phosphorylated p38 MAPK and p38 MAPKα was observed in the pulmonary vasculature from patients with idiopathic pulmonary arterial hypertension, suggesting a role for activation of this pathway in the PVremod A reduction of IL-6 levels in serum and lung tissue was found in the drug-treated animals, suggesting a potential mechanism for this reversal in PVremod. This study suggests that the p38 MAPK and the α-isoform plays a pathogenic role in both human disease and rodent models of pulmonary hypertension potentially mediated through IL-6. Selective inhibition of this pathway may provide a novel therapeutic approach that targets both remodeling and inflammatory pathways in pulmonary vascular disease.

Severe pulmonary hypertension in lung disease: phenotypes and response to treatment.

Pulmonary hypertension (PH) due to lung disease (World Health Organization (WHO) group 3) is common, but severe PH, arbitrarily defined as mean pulmonary artery pressure ≥35 mmHg is reported in only a small proportion. Whether these should be treated as patients in WHO group 1 (i.e. pulmonary arterial hypertension) with PH-targeted therapies is unknown. We compared the phenotypic characteristics and outcomes of 118 incident patients with severe PH and lung disease with 74 idiopathic pulmonary arterial hypertension (IPAH) patients, all treated with pulmonary vasodilators. Lung disease patients were older, more hypoxaemic, and had lower gas transfer, worse New York Heart Association functional class and lower 6-min walking distance (6MWD) than IPAH patients. Poorer survival in those with lung disease was driven by the interstitial lung disease (ILD) cohort. In contrast to IPAH, where significant improvements in 6MWD and N-terminal pro-brain natruiretic peptide (NT-proBNP) occurred, PH therapy in severe PH lung disease did not lead to improvement in 6MWD or functional class, but neither was deterioration seen. NT-proBNP decreased from 2200 to 1596 pg·mL(-1) (p=0.015). Response varied by lung disease phenotype, with poorer outcomes in patients with ILD and emphysema with preserved forced expiratory volume in 1 s. Further study is required to investigate whether vasodilator therapy may delay disease progression in severe PH with lung disease.

Review of the British Thoracic Society winter meeting 2012, 5 to 7 December, London, UK.

This review highlights new developments in scientific and clinical research presented at the British Thoracic Society Winter Scientific Meeting held from 5 to 7 December 2012. Although a wide spectrum of respiratory research was presented at the meeting the content of the review focuses specifically on the key themes of pleural disease, interstitial lung disease and future therapies in respiratory medicine. Advances in clinical and translational respiratory research presented in the major symposia and spoken sessions related to these areas are summarised. Additional sessions covering lifestyle dilemmas in the context of respiratory disease and the early career investigator awards are also highlighted.

Review of the British Thoracic Society Winter Meeting 2011, 7-9 December, London, U.K.

This is the second annual review of the British Thoracic Society Winter Scientific Meeting held from 7-9 December 2011, which was attended by over 2000 delegates. Although a wide spectrum of respiratory research was presented at the meeting, the content of the review focuses specifically on three key themes: cystic fibrosis, pulmonary vascular disease and thoracic oncology. Advances in clinical and translational respiratory research presented within the major symposia and spoken sessions related to these areas are summarised. Additional sessions recognising topics relevant to the forthcoming 2012 London Olympics are also highlighted.

Cardiac geometry, as assessed by cardiac magnetic resonance, can differentiate subtypes of chronic thromboembolic pulmonary vascular disease.

Background: Ventricular septal flattening reflects RV pressure overload in pulmonary arterial hypertension. Eccentricity index (EI) and pulmonary artery distensibility (PAD) correlate with pulmonary artery pressure. We assessed the utility of these using cardiac magnetic resonance (CMR) to assess for pulmonary hypertension (PH) in patients with chronic thromboembolic disease. This may allow non-invasive differentiation between patients who have chronic thromboembolic pulmonary hypertension (CTEPH) and those with pulmonary vascular obstructions without PH at rest, known as chronic thromboembolic pulmonary disease (CTEPD). Methods: Twenty patients without resting pulmonary hypertension, including ten with chronic thromboembolic disease, and thirty patients with CTEPH were identified from a database at the Scottish Pulmonary Vascular Unit. CMR and right heart catheter had been performed within 96 h of each other. Short-axis views at the level of papillary muscles were used to assess the EI at end-systole and diastole. Pulmonary artery distensibility was calculated using velocity-encoded images attained perpendicular to the main trunk. Results: Eccentricity index at end-systole and end-diastole were higher in CTEPH compared to controls (1.3 ± 0.5 vs. 1.0 ± 0.01; p ≤ 0.01 and (1.22 ± 0.2 vs. 0.98 ± 0.01; p ≤ 0.01, respectively) and compared to those with CTED. PAD was significantly lower in CTEPH compared to controls (0.13 ± 0.1 vs. 0.46 ± 0.23; p ≤ 0.01) and compared to CTED. End-systolic EI and end-diastolic EI correlated with pulmonary vascular hemodynamic indices and exercise variables, including mean pulmonary arterial pressure (R0.74 and 0.75, respectively), cardiac output (R-value -0.4 and -0.4, respectively) NTproBNP (R-value 0.3 and 0.3, respectively) and 6-min walk distance (R-value -0.7 and -0.8 respectively). Pulmonary artery distensibility also correlated with 6-min walk distance (R-value 0.8). Conclusion: Eccentricity index and pulmonary artery distensibility can detect the presence of pulmonary hypertension in chronic thromboembolic disease and differentiate between CTEPH and CTED subgroups. These measures support the use of non-invasive tests including CMR for the detection pulmonary hypertension and may reduce the requirement for right heart catheterization.

Pulmonary thromboembolism in hospitalised patients with COVID-19: a retrospective national study of patients managed in critical care and ward environments in Scotland.

OBJECTIVES: To assess for increase in pulmonary thromboembolism (PTE) in hospitalised patients with COVID-19, in both critical care and ward environments. SETTING: We reviewed all CT pulmonary angiograms (CTPA) performed in Scotland between 23 March 2020 and 31 May 2020 and identified those with COVID-19 using either classical radiological appearances or positive COVID-19 PCR swab. PARTICIPANTS: All hospitalised patients in Scotland with COVID-19 between 23 March 2020 and 31 May 2020 who underwent a CTPA. PRIMARY OUTCOME MEASURE: To assess if the rate of PTE was increased in those with COVID-19 compared with previously published figures of hospitalised patients. SECONDARY OUTCOME MEASURES: To assess the effect of right heart strain or requirement for critical care on mortality. RESULTS: 3401 CTPAs were reviewed. 192 were positive for PTE in patients with evidence of COVID-19 either real-time PCR swab positive for SARS-CoV-2 (n=104) or having radiological changes consistent with COVID-19 (n=88). The total number of hospital admissions in Scotland between 23rd March 2020 and 31st May 2020 with COVID-19 was 5195. The incidence of PTE during this time was 3.7% in all patients admitted to all hospitals in Scotland with COVID-19 during this period. 475 hospitalised patients were managed in critical care (both level 2 and level 3 care), in whom the incidence of PTE was 6% (n=29). 4720 patients did not require admission to critical care, in whom the incidence of PTE was 3.5% (n=163). There was increased risk of death with right heart strain (25/52 vs 128/140 (p<0.01)) and in critical care (15/29 vs 146/163 (p<0.01)). CONCLUSIONS: We have demonstrated an increased risk of PTE in critical care and ward-based environments. Further studies are required to establish effective prophylactic anticoagulation in this group.

Altered network stability in progressive supranuclear palsy.

The clinical syndromes of Progressive Supranuclear Palsy (PSP) may be mediated by abnormal temporal dynamics of brain networks, due to the impact of atrophy, synapse loss and neurotransmitter deficits. We tested the hypothesis that alterations in signal complexity in neural networks influence short-latency state transitions. Ninety-four participants with PSP and 64 healthy controls were recruited from two independent cohorts. All participants underwent clinical and neuropsychological testing and resting-state functional MRI. Network dynamics were assessed using hidden Markov models and neural signal complexity measured in terms of multiscale entropy. In both cohorts, PSP increased the proportion of time in networks associated with higher cognitive functions. This effect correlated with clinical severity as measured by the PSP-rating-scale, and with reduced neural signal complexity. Regional atrophy influenced abnormal brain-state occupancy, but abnormal network topology and dynamics were not restricted to areas of atrophy. Our findings show that the pathology of PSP causes clinically relevant changes in neural temporal dynamics, leading to a greater proportion of time in inefficient brain-states.

Hyposmia in progressive supranuclear palsy.

Previous studies suggested that olfaction is normal in progressive supranuclear palsy (PSP). We applied the University of Pennsylvania Smell Identification Test (UPSIT) to 36 patients with PSP who scored more than 18 on the Mini Mental State Examination (MMSE), 140 patients with nondemented Parkinson's disease (PD) and 126 controls. Mean UPSIT scores in PSP were lower than in controls (P < 0.001) but higher than in PD (P < 0.001) after adjusting for age, gender, and smoking history. For patients with PSP, UPSIT scores correlated with MMSE (r = 0.44, P = 0.006) but not disease duration (P = 0.6), motor subscale of the Unified Parkinson's Disease Rating Scale (P = 0.2), or Frontal Assessment Battery (P = 0.5). The brains of six of the patients with PSP were examined postmortem and all revealed neurofibrillary tangles and tau accumulation in the rhinencephalon, although only three had hyposmia. Further prospective studies including patients with early PSP and PSP-P with postmortem confirmation might help clarify if smell tests could be useful when the differential diagnosis lies between PD and PSP.