Project description:BackgroundProgressive supranuclear palsy (PSP) causes major disability, shortens life, and as yet has no disease-modifying and little symptomatic treatment. A convenient prognostic tool is needed to assist patients, families, and clinicians in planning care.ObjectivesWe calculated times to acquisition of certain disease milestones and death.MethodsWe followed a cohort of 417 patients with PSP-Richardson syndrome from 1995 to 2016, applying the Progressive Supranuclear Palsy Rating Scale (PSPRS) at each visit. We generated median times to acquisition of 13 milestones using the input variables of sex, onset age, rate of disease progression from motor symptom onset to initial visit, and PSPRS score at the baseline. Of the outcome milestones, 5 were stages of a new, provisional PSP staging system. The other 8 milestones comprised death and disabling levels of cognitive loss, gaze palsy, dysarthria, dysphagia, and gait/balance impairment.ResultsWe derived median times to milestones, with 25th and 75th percentiles and 95% confidence intervals of the median for baseline PSPRS scores from 25 to 65 (scale range, 0-100). Sex and initial progression velocity significantly influenced the death milestone, but not most of the others. Median time to death ranged from 4.8 years for a man with PSPRS score of 25 and a slow progression velocity from onset to initial visit of 0.51 PSPRS points/month to 1.8 years for a woman with PSPRS 65 and rapid initial velocity of 2.25 points/month.ConclusionsWe have created a convenient, inexpensive, noninvasive reference for counseling patients with PSP-Richardson syndrome on approximate time to encountering 13 life-altering disease milestones.
Project description:Progressive supranuclear palsy (PSP) is an atypical Parkinsonian disorder associated with progressive axial rigidity, vertical gaze palsy, dysarthria and dysphagia. Neuropathologically, the subthalamic nucleus and brainstem, especially the midbrain tectum and the superior cerebellar peduncle, show atrophy. The substantia nigra shows loss of pigment corresponding to nigrostriatal dopaminergic degeneration. Microscopic findings include neuronal loss, gliosis and neurofibrillary tangles in basal ganglia, diencephalon and brainstem. Characteristic tau pathology is also found in glia. The major genetic risk factor for sporadic PSP is a common variant in the gene encoding microtubule-associated protein tau (MAPT) and recent studies have suggested that this may result in the altered expression of specific tau protein isoforms. Imaging studies suggest that there may be sensitive and specific means to differentiate PSP from other parkinsonian disorders, but identification of a diagnostic biomarker is still elusive.
Project description:The development of novel treatments for Progressive Supranuclear Palsy (PSP) is hindered by a knowledge gap of the impact of neurodegenerative neuropathology on brain structure and function. The current standard practice for measuring postmortem tau histology is semi-quantitative assessment, which is prone to inter-rater variability, time-consuming and difficult to scale. We developed and optimized a tau aggregate type-specific quantification pipeline for cortical and subcortical regions, in human brain donors with PSP. We quantified 4 tau objects ('neurofibrillary tangles', 'coiled bodies', 'tufted astrocytes', and 'tau fragments') using a probabilistic random forest machine learning classifier. The tau pipeline achieved high classification performance (F1-score > 0.90), comparable to neuropathologist inter-rater reliability in the held-out test set. Using 240 AT8 slides from 32 postmortem brains, the tau burden was correlated against the PSP pathology staging scheme using Spearman's rank correlation. We assessed whether clinical severity (PSP rating scale, PSPRS) score reflects neuropathological severity inferred from PSP stage and tau burden using Bayesian linear mixed regression. Tufted astrocyte density in cortical regions and coiled body density in subcortical regions showed the highest correlation to PSP stage (r = 0.62 and r = 0.38, respectively). Using traditional manual staging, only PSP patients in stage 6, not earlier stages, had significantly higher clinical severity than stage 2. Cortical tau density and neurofibrillary tangle density in subcortical regions correlated with clinical severity. Overall, our data indicate the potential for highly accurate digital tau aggregate type-specific quantification for neurodegenerative tauopathies; and the importance of studying tau aggregate type-specific burden in different brain regions as opposed to overall tau, to gain insights into the pathogenesis and progression of tauopathies.
Project description:Progressive supranuclear palsy is a rare form of atypical Parkinsonism that differs neuropathologically from other parkinsonian disorders. While many parkinsonian disorders such as Parkinson's disease, Lewy body dementia, and multiple system atrophy are classified as synucleinopathies, progressive supranuclear palsy is coined a tauopathy due to the aggregation of pathological tau in the brain. [18F]AV-1451 (also known as [18F]-T807) is a positron emission tomography radiotracer that binds to paired helical filaments of tau in Alzheimer's disease. We investigated whether [18F]AV-1451 could be used as biomarker for the diagnosis and disease progression monitoring in progressive supranuclear palsy. Six progressive supranuclear palsy, six Parkinson's disease, and 10 age-matched healthy controls were recruited. An anatomical MRI and a 90-min PET scan, using [18F]AV-1451, were acquired from all participants. The standardized uptake value ratio from 60 to 90 min post-injection was calculated in each region of interest, using the cerebellar cortex as a reference region. No significant differences in standardized uptake value ratios were detected in our progressive supranuclear palsy group compared to the two control groups. [18F]AV-1451 may bind selectivity to the paired helical filaments in Alzheimer's disease, which differ from the straight conformation of tau filaments in progressive supranuclear palsy.
Project description:IntroductionThere is growing interest in using patient-reported outcomes as end points in clinical trials, such as the progressive supranuclear palsy quality of life (PSP-QoL) scale. However, this tool has not been widely validated and its correlation with validated motor scales has not been explored. To evaluate the potential utility of using PSP-QoL as an outcome, it is important to examine its relationship with a standard scale used to evaluate neurologic parameters, such as the PSP Rating Scale.MethodsPSP-QoL and PSP Rating Scale scores were gathered from 60 clinically diagnosed PSP patients, including patients with Richardson syndrome PSP (PSP-RS, n = 43) and those with non-RS PSP variants (n = 17). Linear regression analysis adjusted for age, sex, and disease duration was used to evaluate the cross-sectional relationship between the total and subscale scores of the 2 instruments.ResultsAmong 60 PSP patients, there was a significant correlation between total PSP-QoL and PSP Rating Scale scores. The physical and mentation subscales of each instrument also demonstrated significant correlations. Comparisons among PSP subtypes indicated that worsening PSP-QoL Total and Physical subscale scores correlated with worsening PSP Rating Scale gait subscale scores more strongly for the non-RS PSP variants than for PSP-RS.DiscussionThere is a significant association between the total scores and many of the subscale scores of the PSP-QoL and the PSP Rating Scale. Additionally, the relationship between these measures may differ for PSP-RS and non-RS variants. These findings suggest that the PSP-QoL may be useful in clinical trials as a patient-reported outcome measure. Large prospective multicenter studies utilizing the PSP-QoL are necessary to examine its relationship to disease evolution and changes in the PSP Rating Scale.
Project description:BackgroundWe aimed to produce a detailed neuropathological analysis of pyramidal motor system pathology and provide its clinical pathological correlation in cases with definite progressive supranuclear palsy (PSP).MethodsPyramidal motor system pathologies were analyzed in 18 cases with neuropathologically confirmed PSP. Based on a retrospective clinical analysis, cases were subtyped according to Movement Disorder Society criteria for clinical diagnosis of PSP as probable, possible or suggestive of PSP with Richardson's syndrome (n = 10), PSP with predominant corticobasal syndrome (n = 3), PSP with predominant parkinsonism (n = 3), PSP with predominant speech/language disorder (n = 1), and PSP with progressive gait freezing (n = 1). Clinical manifestations of motor neuron involvement (pseudobulbar or bulbar signs and spasticity) were retrospectively assessed semiquantitatively. Neuropathologically, hyperphosphorylated tau-related pyramidal motor system neuronal, neuritic, and glial pathology using anti-tau AT8 clone immunohistochemistry, was also evaluated.ResultsClinical manifestations of pyramidal motor system involvement were found in patients with different PSP subtypes. A statistically significant higher load of tau pathology was found in the pyramidal system in PSP-Richardson's syndrome compared to other PSP subtypes (p = 0.016); however, there was no significant correlation between pyramidal system tau pathology and related motor clinical symptoms.ConclusionsTau pathology in the spinal cord and pyramidal motor system structures is very common in progressive supranuclear palsy and may neuropathologically supplement the distinction between classic Richardson's syndrome from other progressive supranuclear palsy subtypes.
Project description:Progressive supranuclear palsy (PSP) is a neurodegenerative syndrome that is clinically characterized by progressive postural instability, supranuclear gaze palsy, parkinsonism and cognitive decline. Pathologically, diagnosis of PSP is based on characteristic features, such as neurofibrillary tangles, neutrophil threads, tau-positive astrocytes and their processes in basal ganglia and brainstem, and the accumulation of 4 repeat tau protein. PSP is generally recognized as a sporadic disorder; however, understanding of genetic background of PSP has been expanding rapidly. Here we review relevant publications to outline the genetics of PSP. Although only small number of familial PSP cases have been reported, the recognition of familial PSP has been increasing. In some familial cases of clinically probable PSP, PSP pathologies were confirmed based on NINDS neuropathological diagnostic criteria. Several mutations in MAPT, the gene that causes a form of familial frontotemporal lobar degeneration with tauopathy, have been identified in both sporadic and familial PSP cases. The H1 haplotype of MAPT is a risk haplotype for PSP, and within H1, a sub-haplotype (H1c) is associated with PSP. A recent genome-wide association study on autopsyproven PSP revealed additional PSP risk alleles in STX6 and EIF2AK3. Several heredodegenerative parkinsonian disorders are referred to as PSP-look-alikes because their clinical phenotype, but not their pathology, mimics PSP. Due to the fast development of genomics and bioinformatics, more genetic factors related to PSP are expected to be discovered. Undoubtedly, these studies will provide a better understanding of the pathogenesis of PSP and clues for developing therapeutic strategies.
Project description:Purpose of reviewProgressive supranuclear palsy (PSP) is a progressive adult-onset neurodegenerative disease. Abnormally, phosphorylated forms of the microtubule-associated protein tau containing four repeat domains (4R-tau) aggregate in neurons. Additionally, increasing evidence suggests that secretion and uptake of fragments of abnormal 4R-tau may play a role in disease progression. This extracellular tau is a natural target for immunotherapy.Recent findingsThree monoclonal antibodies targeting extracellular tau are in clinical stages of development. ABBV-8E12 and BIIB092 were safe in Phase 1, but both Phase two studies recently failed futility analyses. UCB0107 recently reported (in abstract form) Phase 1 safety results, and a Phase 2 study is under consideration. Stem cell therapy and the infusion of plasma are also being explored clinically.SummaryThe likely role of extracellular tau in the progression of PSP makes tau a natural target for targeted immunotherapy. Clinical trials are still in early stages, and although tau immunotherapy has largely been shown to be safe, efficacy has yet to be demonstrated.