Summary Background In preclinical studies, davunetide promoted microtubule stability and reduced tau phosphorylation. Because progressive supranuclear palsy (PSP) is linked to tau pathology, ...davunetide could be a treatment for PSP. We assessed the safety and efficacy of davunetide in patients with PSP. Methods In a double-blind, parallel group, phase 2/3 trial, participants were randomly assigned with permuted blocks in a 1:1 ratio to davunetide (30 mg twice daily, intranasally) or placebo for 52 weeks at 48 centres in Australia, Canada, France, Germany, the UK, and the USA. Participants met the modified Neuroprotection and Natural History in Parkinson Plus Syndrome study criteria for PSP. Primary endpoints were the change from baseline in PSP Rating Scale (PSPRS) and Schwab and England Activities of Daily Living (SEADL) scale at up to 52 weeks. All participants and study personnel were masked to treatment assignment. Analysis was by intention to treat. The trial is registered with Clinicaltrials.gov , number NCT01110720. Findings 313 participants were randomly assigned to davunetide (n=157) or to placebo (n=156), and 241 (77%) completed the study (118 and 156 in the davunetide and placebo groups, respectively). There were no differences in the davunetide and placebo groups in the baseline PSPRS and SEADL. The davunetide and placebo groups did not differ in the change from baseline in PSPRS (median 11·8 95% CI 10·5 to 13·0 vs 11·8 10·5 to 13·0, respectively, p=0·41) or SEADL (−0·20 −0·20 to −0·17 vs −0·20 −0·22 to −0·17, respectively, p=0·92). 54 serious adverse events were reported in each of the treatment groups, including 11 deaths in the davunetide group and ten in the placebo group. The frequency of nasal adverse events was greater in the davunetide group than in the placebo group (epistaxis 18 12% of 156 vs 13 8% of 156, rhinorrhoea 15 10% vs eight 5%, and nasal discomfort 15 10% vs one <1%). Interpretation Davunetide is not an effective treatment for PSP. Clinical trials of disease-modifying treatment are feasible in patients with PSP and should be pursued with other promising tau-directed treatments. Funding Allon Therapeutics.
GRN mutations cause frontotemporal dementia (GRN-FTD) due to deficiency in progranulin (PGRN), a lysosomal and secreted protein with unclear function. Here, we found that Grn–/– mice exhibit a global ...deficiency in bis(monoacylglycero)phosphate (BMP), an endolysosomal phospholipid we identified as a pH-dependent PGRN interactor as well as a redox-sensitive enhancer of lysosomal proteolysis and lipolysis. Grn–/– brains also showed an age-dependent, secondary storage of glucocerebrosidase substrate glucosylsphingosine. We investigated a protein replacement strategy by engineering protein transport vehicle (PTV):PGRN—a recombinant protein linking PGRN to a modified Fc domain that binds human transferrin receptor for enhanced CNS biodistribution. PTV:PGRN rescued various Grn–/– phenotypes in primary murine macrophages and human iPSC-derived microglia, including oxidative stress, lysosomal dysfunction, and endomembrane damage. Peripherally delivered PTV:PGRN corrected levels of BMP, glucosylsphingosine, and disease pathology in Grn–/– CNS, including microgliosis, lipofuscinosis, and neuronal damage. PTV:PGRN thus represents a potential biotherapeutic for GRN-FTD.
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•Grn–/– mice exhibit robust BMP lipid deficiency with concurrent GlcSph accumulation•BMP stimulates glucocerebrosidase activity and lysosome function in Grn–/– models•PGRN was fused to a human transferrin receptor binding Fc to increase CNS exposure•PTV:PGRN biologic rescues Grn–/– CNS lysosomal, microglial, and neuronal dysfunction
Peripherally delivered progranulin biologic with enhanced CNS biodistribution corrects CNS disease pathology of the GRN mouse model of frontotemporal dementia.
Despite recent advances in fluid biomarker research in Alzheimer's disease (AD), there are no fluid biomarkers or imaging tracers with utility for diagnosis and/or theragnosis available for other ...tauopathies. Using immunoprecipitation and mass spectrometry, we show that 4 repeat (4R) isoform-specific tau species from microtubule-binding region (MTBR-tau
and MTBR-tau
) increase in the brains of corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), frontotemporal lobar degeneration (FTLD)-MAPT and AD but decrease inversely in the cerebrospinal fluid (CSF) of CBD, FTLD-MAPT and AD compared to control and other FTLD-tau (for example, Pick's disease). CSF MTBR-tau measures are reproducible in repeated lumbar punctures and can be used to distinguish CBD from control (receiver operating characteristic area under the curve (AUC) = 0.889) and other FTLD-tau, such as PSP (AUC = 0.886). CSF MTBR-tau
and MTBR-tau
may represent the first affirmative biomarkers to aid in the diagnosis of primary tauopathies and facilitate clinical trial designs.
The aims of this study were to examine executive dysfunction using an antisaccade (AS) task in normal elderly (NE) and patients with mild cognitive impairment (MCI) and Alzheimer disease (AD) as well ...as to evaluate the relationship between AS performance and cortical thinning within AD-associated regions.
We recorded eye movements in 182 subjects (NE: 118; MCI: 36; AD: 28) during an AS task. We also performed neuropsychological measures of executive function for comparison. Brain MRI scans were collected on most subjects, and cortical thickness was determined in 9 regions known to exhibit atrophy in AD dementia ("AD signature"). We investigated the relationships between AS and neuropsychological performance, as well as possible correlations between AS performance and cortical thickness.
AS performance in MCI resembled that in NE; subjects with AD were impaired relative to both MCI and NE. In all subjects, AS performance correlated with neuropsychological measures of executive function, even after controlling for disease severity. In the subjects with MCI but not in NE, cortical thickness in frontoparietal AD signature regions correlated with AS performance.
The AS task is a useful measure of executive function across the AD spectrum. In MCI, AS performance may reflect disease burden within cortical brain regions involved in oculomotor control; however, AS impairments in NE may have etiologies other than incipient AD.
Introduction
Behavior/Comportment/Personality (BEHAV) and Language (LANG) domains were added to the Clinical Dementia Rating (CDR®) for improving evaluation of patients with frontotemporal lobar ...degeneration (FTLD) (CDR® plus NACC FTLD).
Methods
We analyzed the CDR® plus NACC FTLD among participants from the baseline visit of the Advancing Research and Treatment for Frontotemporal Lobar Degeneration/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects Consortium.
Results
The CDR® plus NACC FTLD was able to detect early symptoms in the mildly impaired participants who were rated as CDR® sum of boxes (CDR®‐SB) = 0. The CDR®‐SB was not sensitive, particularly in participants with mild nonfluent/agrammatic primary progressive aphasia. Participants with familial and sporadic behavioral variant FTD exhibited similar CDR® plus NACC FTLD profiles except that language impairment was more frequent in participants with mild sporadic behavioral variant FTD. Adding the BEHAV and/or LANG domains to the CDR®‐SB significantly enhanced discriminatory power in differentiating among the FTLD spectrum disorders.
Discussion
The BEHAV and LANG domains enable the CDR® plus NACC FTLD to capture early symptomatology of FTLD.
Objective
Progressive supranuclear palsy (PSP) has been conceptualized as a large‐scale network disruption, but the specific network targeted has not been fully characterized. We sought to delineate ...the affected network in patients with clinical PSP.
Methods
Using task‐free functional magnetic resonance imaging, we mapped intrinsic connectivity to the dorsal midbrain tegmentum (dMT), a region that shows focal atrophy in PSP. Two healthy control groups (1 young, 1 older) were used to define and replicate the normal connectivity pattern, and patients with PSP were compared to an independent matched healthy control group on measures of network connectivity.
Results
Healthy young and older subjects showed a convergent pattern of connectivity to the dMT, including brainstem, cerebellar, diencephalic, basal ganglia, and cortical regions involved in skeletomotor, oculomotor, and executive control. Patients with PSP showed significant connectivity disruptions within this network, particularly within corticosubcortical and cortico‐brainstem interactions. Patients with more severe functional impairment showed lower mean dMT network connectivity scores.
Interpretation
This study defines a PSP‐related intrinsic connectivity network in the healthy brain and demonstrates the sensitivity of network‐based imaging methods to PSP‐related physiological and clinical changes. Ann Neurol 2013;73:603–616
Sleep disturbance is common among patients with neurodegenerative diseases. Examining the subcortical neuronal correlates of sleep disturbances is important to understanding the early-stage sleep ...neurodegenerative phenomena.
To examine the correlation between the number of important subcortical wake-promoting neurons and clinical sleep phenotypes in patients with Alzheimer disease (AD) or progressive supranuclear palsy (PSP).
This longitudinal cohort study enrolled 33 patients with AD, 20 patients with PSP, and 32 healthy individuals from the Memory and Aging Center of the University of California, San Francisco, between August 22, 2008, and December 31, 2020. Participants received electroencephalographic and polysomnographic sleep assessments. Postmortem neuronal analyses of brainstem hypothalamic wake-promoting neurons were performed and were included in the clinicopathological correlation analysis. No eligible participants were excluded from the study.
Electroencephalographic and polysomnographic assessment of sleep and postmortem immunohistological stereological analysis of 3 wake-promoting nuclei (noradrenergic locus coeruleus LC, orexinergic lateral hypothalamic area LHA, and histaminergic tuberomammillary nucleus TMN).
Nocturnal sleep variables, including total sleep time, sleep maintenance, rapid eye movement (REM) latency, and time spent in REM sleep and stages 1, 2, and 3 of non-REM (NREM1, NREM2, and NREM3, respectively) sleep, and wake after sleep onset. Neurotransmitter, tau, and total neuronal counts of LC, LHA, and TMN.
Among 19 patients included in the clinicopathological correlation analysis, the mean (SD) age at death was 70.53 (7.75) years; 10 patients (52.6%) were female; and all patients were White. After adjusting for primary diagnosis, age, sex, and time between sleep analyses and death, greater numbers of LHA and TMN neurons were correlated with decreased homeostatic sleep drive, as observed by less total sleep time (LHA: r = -0.63; P = .009; TMN: r = -0.62; P = .008), lower sleep maintenance (LHA: r = -0.85; P < .001; TMN: r = -0.78; P < .001), and greater percentage of wake after sleep onset (LHA: r = 0.85; P < .001; TMN: r = 0.78; P < .001). In addition, greater numbers of LHA and TMN neurons were correlated with less NREM2 sleep (LHA: r = -0.76; P < .001; TMN: r = -0.73; P < .001). A greater number of TMN neurons was also correlated with less REM sleep (r = -0.61; P = .01). A greater number of LC neurons was mainly correlated with less total sleep time (r = -0.68; P = .008) and greater REM latency (r = 0.71; P = .006). The AD-predominant group had significantly greater sleep drive, including higher total sleep time (mean SD, 0.49 1.18 vs -1.09 1.37; P = .03), higher sleep maintenance (mean SD, 0.18 1.22 vs -1.53 1.78; P = .02), and lower percentage of wake after sleep onset during sleep period time (mean SD, -0.18 1.20 vs 1.49 1.72; P = .02) than the PSP-predominant group based on unbiased k-means clustering and principal component analyses.
In this cohort study, subcortical wake-promoting neurons were significantly correlated with sleep phenotypes in patients with AD and PSP, suggesting that the loss of wake-promoting neurons among patients with neurodegenerative conditions may disturb the control of sleep-wake homeostasis. These findings suggest that the subcortical system is a primary mechanism associated with sleep disturbances in the early stages of neurodegenerative diseases.
Introduction
We created global rating scoring rules for the CDR® plus NACC FTLD to detect and track early frontotemporal lobar degeneration (FTLD) and to conduct clinical trials in FTLD.
Methods
The ...CDR plus NACC FTLD rating was applied to 970 sporadic and familial participants from the baseline visit of Advancing Research and Treatment in Frontotemporal Lobar Degeneration (ARTFL)/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects (LEFFTDS). Each of the eight domains of the CDR plus NACC FTLD was equally weighed in determining the global score. An interrater reliability study was completed for 40 participants.
Results
The CDR plus NACC FTLD showed very good interrater reliability. It was especially useful in detecting clinical features of mild non‐fluent/agrammatic variant primary progressive aphasia participants.
Discussion
The global CDR plus NACC FTLD score could be an attractive outcome measure for clinical trials in symptomatic FTLD, and may be useful in natural history studies and clinical trials in FTLD spectrum disorders.
At present, no research criteria exist for the diagnosis of prodromal behavioural variant frontotemporal dementia (bvFTD), though early detection is of high research importance. Thus, we sought to ...develop and validate a proposed set of research criteria for prodromal bvFTD, termed 'mild behavioural and/or cognitive impairment in bvFTD' (MBCI-FTD). Participants included 72 participants deemed to have prodromal bvFTD; this comprised 55 carriers of a pathogenic mutation known to cause frontotemporal lobar degeneration, and 17 individuals with autopsy-confirmed frontotemporal lobar degeneration. All had mild behavioural and/or cognitive changes, as judged by an evaluating clinician. Based on extensive clinical workup, the prodromal bvFTD group was divided into a Development Group (n = 22) and a Validation Group (n = 50). The Development Group was selected to be the subset of the prodromal bvFTD group for whom we had the strongest longitudinal evidence of conversion to bvFTD, and was used to develop the MBCI-FTD criteria. The Validation Group was the remainder of the prodromal bvFTD group and was used as a separate sample on which to validate the criteria. Familial non-carriers were included as healthy controls (n = 165). The frequencies of behavioural and neuropsychiatric features, neuropsychological deficits, and social cognitive dysfunction in the prodromal bvFTD Development Group and healthy controls were assessed. Based on sensitivity and specificity analyses, seven core features were identified: apathy without moderate-severe dysphoria, behavioural disinhibition, irritability/agitation, reduced empathy/sympathy, repetitive behaviours (simple and/or complex), joviality/gregariousness, and appetite changes/hyperorality. Supportive features include a neuropsychological profile of impaired executive function or naming with intact orientation and visuospatial skills, reduced insight for cognitive or behavioural changes, and poor social cognition. Three core features or two core features plus one supportive feature are required for the diagnosis of possible MBCI-FTD; probable MBCI-FTD requires imaging or biomarker evidence, or a pathogenic genetic mutation. The proposed MBCI-FTD criteria correctly classified 95% of the prodromal bvFTD Development Group, and 74% of the prodromal bvFTD Validation Group, with a false positive rate of <10% in healthy controls. Finally, the MBCI-FTD criteria were tested on a cohort of individuals with prodromal Alzheimer's disease, and the false positive rate of diagnosis was 11-16%. Future research will need to refine the sensitivity and specificity of these criteria, and incorporate emerging biomarker evidence.
Microtubule-associated protein tau (MAPT) mutations cause frontotemporal lobar degeneration, and novel biomarkers are urgently needed for early disease detection. We used task-free functional ...magnetic resonance imaging (fMRI) mapping, a promising biomarker, to analyze network connectivity in symptomatic and presymptomatic MAPT mutation carriers.
We compared cross-sectional fMRI data between 17 symptomatic and 39 presymptomatic carriers and 81 controls with (1) seed-based analyses to examine connectivity within networks associated with the 4 most common MAPT-associated clinical syndromes (ie, salience, corticobasal syndrome, progressive supranuclear palsy syndrome, and default mode networks) and (2) whole-brain connectivity analyses. We applied K-means clustering to explore connectivity heterogeneity in presymptomatic carriers at baseline. Neuropsychological measures, plasma neurofilament light chain, and gray matter volume were compared at baseline and longitudinally between the presymptomatic subgroups defined by their baseline whole-brain connectivity profiles.
Symptomatic and presymptomatic carriers had connectivity disruptions within MAPT-syndromic networks. Compared to controls, presymptomatic carriers showed regions of connectivity alterations with age. Two presymptomatic subgroups were identified by clustering analysis, exhibiting predominantly either whole-brain hypoconnectivity or hyperconnectivity at baseline. At baseline, these two presymptomatic subgroups did not differ in neuropsychological measures, although the hypoconnectivity subgroup had greater plasma neurofilament light chain levels than controls. Longitudinally, both subgroups showed visual memory decline (vs controls), yet the subgroup with baseline hypoconnectivity also had worsening verbal memory and neuropsychiatric symptoms, and extensive bilateral mesial temporal gray matter decline.
Network connectivity alterations arise as early as the presymptomatic phase. Future studies will determine whether presymptomatic carriers' baseline connectivity profiles predict symptomatic conversion. ANN NEUROL 2023;94:632-646.
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