Differential Diagnosis of Rare Subtypes of Progressive Supranuclear Palsy and PSP-Like Syndromes—Infrequent Manifestations of the Most Common Form of Atypical Parkinsonism

Progression of Motor Speech Function in Speakers With Primary Progressive Apraxia of Speech

PURPOSE

Speakers with primary progressive apraxia of speech (PPAOS) have an insidious onset of motor speech planning/programming difficulties. As the disease progresses, the apraxia of speech (AOS) becomes more severe and a co-occurring dysarthria often emerges. Here, longitudinal data from speakers with phonetic- and prosodic-predominant PPAOS are used to characterize the progression of their motor speech impairment, including the development of dysarthria and mutism.

METHOD

Data are presented from 52 speakers who had PPAOS at enrollment (i.e., progressive AOS in the absence of aphasia, cognitive, or other neurologic symptoms). Twenty-one had predominantly phonetic features, whereas 31 had primarily prosodic features. All participants underwent a comprehensive motor speech evaluation at their enrollment visit and each annual return visit, with a median of three visits per participant.

RESULTS

Almost 25% of the speakers with PPAOS presented with dysarthria at their enrollment visit (median disease duration of 3.65 years), whereas more than 70% of them had developed dysarthria by their last visit (median disease duration of 6.85 years). Neither the likelihood to develop dysarthria nor the disease duration at which it was detected differed significantly between the phonetic and prosodic groups. However, muteness emerged sooner for speakers with phonetic-predominant PPAOS; the median disease duration at which they became mute was 1.5 years shorter than for their prosodic counterparts.

CONCLUSIONS

Clinically, these results facilitate more accurate prognostication of motor speech symptoms in speakers with PPAOS, allowing for timely introduction of alternative means of communication. The results also support the differentiation between progressive AOS and dysarthria as distinct motor speech disorders that often co-occur in these individuals.

Dysphagia in progressive supranuclear palsy: A scoping review

Introduction

One of the most prevalent types of atypical parkinsonian syndrome is progressive supranuclear palsy (PSP). PSP is associated with early onset of dysphagia which can result in malnutrition, dehydration, and aspiration pneumonia, affecting quality of life and increasing mortality rate. To date, research describing dysphagia in PSP and its impact is scant.

Methods

The objective of this scoping review is to determine the characteristics of dysphagia in PSP, differences in dysphagia presentation according to PSP subtype, principal methods used for identifying and diagnosing dysphagia and the impact dysphagia has on quality of life in individuals with PSP. This review was conducted in accordance with the JBI methodology. Six electronic databases were searched.

Results

Of the 20 studies included, the most frequently reported characteristics of dysphagia were oral preparatory and oral phase difficulties. A variety of methods were used to identify and diagnose dysphagia including instrumental assessment (65%), patient reported scales (45%) and clinical swallow evaluation (20%). The most used instrumental assessment was videofluoroscopy (46%). Limited data was available describing characteristics of dysphagia according to the subtype of PSP. The impact that dysphagia has on quality of life was assessed in only one study.

Conclusion

A range of assessment methods are used to identify and diagnose dysphagia in patients with PSP. Further research is needed to investigate if particular characteristics are associated with certain PSP subtypes. Future studies should also measure the impact that dysphagia has on quality of life in this population.

Autoimmune Encephalitis and Paraneoplastic Neurological Syndromes with Progressive Supranuclear Palsy-like Manifestations

BACKGROUND

Advances in diagnostic procedures have led to an increasing rate of diagnosis of autoimmune encephalitis or paraneoplastic neurological syndrome (AE/PNS) among patients with progressive supranuclear palsy (PSP)-like manifestations.

METHODS

In this narrative review, we first discuss the clinical characteristics of AE/PNS in comparison to those of PSP, followed by a discussion of diagnosis and treatment.

RESULTS

The antibodies involved in these conditions include anti-IgLON5, -Ma2, and -Ri antibodies, each of which has a characteristic clinical presentation. The steps in the diagnosis of AE/PNS in patients with PSP-like manifestations include (i) suspicion of AE/PNS based on clinical presentations atypical of PSP and (ii) antibody detection measures. Methods used to identify antibodies include a combination of tissue-based assays and confirmatory tests. The primary confirmatory tests include cell-based assays and immunoblotting. Treatments can be divided into immunotherapy and tumor therapies, the former of which includes acute and maintenance therapies.

CONCLUSIONS

One of the major challenges of diagnosis is that existing reports on PSP-like patients with AE/PNS include only case reports, with the majority discussing antibodies other than anti-IgLON5 antibody. As such, more patients need to be evaluated to establish the relationship between antibodies and PSP-like manifestations.

The associations between common neuroimaging parameters of Progressive Supranuclear Palsy in magnetic resonance imaging and non-specific inflammatory factors - pilot study

Progressive Supranuclear Palsy is an atypical parkinsonism based on tauopathic pathology. Growing interest is associated with the pathomechanism of this disease. Among theories analyzing this issue can be mentioned the one highlighting the significance of inflammation. In this study authors examined 14 patients with PSP-Richardson syndrome (PSP-RS) and 13 healthy volunteers using laboratory testing based on the analysis of interleukins 1 and 6 (IL-1 and IL-6), tau in the cerebrospinal fluid (CSF) and non-specific parameters of peripheral inflammation in the serum (IL-1, IL-6, neutrophils, lymphocytes, monocytes, platelets and the ratios based on the factors). All of the patients underwent neuroimaging using magnetic resonance imaging using 3 Tesla. The serum levels of IL-1 were positively correlated with the area of the mesencephalon, suggesting that higher levels of IL-1 are not linked with atrophic changes in this region, whereas serum levels IL-6 was positively correlated with frontal horn width and negatively correlated with superior cerebellar area. Additionally IL-6 in the serum was found to be correlated with neutrophil-to-high density lipoprotein ratio. The observations were not confirmed in the analysis of the levels of interleukins in the CSF. To the best of our knowledge this work is one of the first analyzing this issue. The outcome of the work shows that the role of interleukins associated with microglial activation may possibly differ in the context of neurodegenerative changes, moreover the role of peripheral inflammation in PSP requires further analysis.

Progressive supranuclear palsy, a case report

Progressive Supranuclear Palsy (PSP), also known as Steele-Richardson-Olszewski syndrome, is a rare neurodegenerative disease characterized by a variety of motor and neuro-ophthalmological symptoms. We present the case of a 73-year-old male patient with a history of type 2 diabetes and high blood pressure, who consulted for gait disorders, tremors in the extremities, and difficulty controlling conjugate gaze. During physical examination, findings consistent with PSP were noted, including hypomimia, muscle rigidity, and abnormal movements. The initial misdiagnosis of Parkinson's disease and subsequent administration of levodopa highlight the importance of accurate diagnosis in complex neurological conditions. This clinical case highlights the need for a thorough evaluation of neuro-ophthalmological symptoms and signs to ensure an appropriate therapeutic approach and improve the quality of life of patients.

PSP-Richardson syndrome mimics: An overview and pragmatic approach

Progressive supranuclear palsy-Richardson syndrome (PSP-RS) is a sporadic atypical parkinsonian syndrome with levodopa-unresponsive axial-predominant parkinsonism, early postural instability, vertical supranuclear gaze palsy, dysarthria, executive dysfunction and behavioural changes. PSP-RS can be mimicked by numbers of other disorders, generally known as PSP mimics, or PSP-like syndromes. Their aetiological spectrum includes neurodegenerative (mostly genetic), vascular, infectious and drug-induced illnesses as well as other causes. Based on the available data, we have tried to create a definition of PSP-RS mimics: a syndrome resembling PSP-RS with at least one of the following red flags: 1) positive family history; 2) onset before 45 years of age; 3) rapid or stepwise progression; 4) acute or subacute onset; 5) atypical symptoms and/or signs; 6) normal or atypical brain MRI; 7) history of HIV or untreated syphilis, aortal surgery or recent therapy with dopamine-blocking agents. We have suggested a short diagnostic algorithm leading to the identification of PSP-RS mimics and the recommended diagnostic work-up. The key point of the diagnostic process is the early identification and treatment of potentially treatable PSP-RS mimics.

Anomia: Deciphering Functional Neuroanatomy in Primary Progressive Aphasia Variants

Naming decline is one of the most common symptoms of primary progressive aphasia (PPA). Most studies on anomia in PPA are performed without taking into account PPA variants, especially for action naming. Only limited data are available for the neuroanatomical basis of anomia considering differences in the pathogenesis of PPAs. The aim of our study is to investigate the associations between anomia severity for both noun and verb naming and gray matter (GM) atrophy, as well as accompanying functional connectivity (FC) changes in three PPA variants. A total of 17 patients with non-fluent (nfvPPA), 11 with semantic (svPPA), and 9 with logopenic (lvPPA) PPA variants were included in the study and underwent cognitive/naming assessments and brain MRIs. Voxel-based morphometry was performed to evaluate GM volume. A resting-state functional MRI was applied to investigate FC changes in the identified GM areas. The study shows that different brain regions are involved in naming decline in each PPA variant with a predominantly temporal lobe involvement in svPPA, parietal lobe involvement in lvPPA, and frontal lobe involvement in nfvPPA. Separate data for object and action naming in PPA variants are provided. The obtained results mainly correspond to the current understanding of language processing and indicate that the evaluation of language impairments is preferable for each PPA variant separately. A further analysis of larger cohorts of patients is necessary to confirm these preliminary results.

Genetic characterization of primary lateral sclerosis

BACKGROUND AND OBJECTIVES

Primary lateral sclerosis (PLS) is a motor neuron disease characterised by loss of the upper motor neurons. Most patients present with slowly progressive spasticity of the legs, which may also spread to the arms or bulbar regions. It is challenging to distinguish between PLS, early-stage amyotrophic lateral sclerosis (ALS) and hereditary spastic paraplegia (HSP). The current diagnostic criteria advise against extensive genetic testing. This recommendation is, however, based on limited data.

METHODS

We aim to genetically characterize a PLS cohort using whole exome sequencing (WES) for genes associated with ALS, HSP, ataxia and movement disorders (364 genes) and C9orf72 repeat expansions. Patients fulfilling the definite PLS criteria by Turner et al. and with available DNA samples of sufficient quality were recruited from an on-going, population-based epidemiological study. Genetic variants were classified according to the ACMG criteria and assigned to groups based on disease association.

RESULTS

WES was performed in 139 patients and the presence of repeat expansions in C9orf72 was analysed separately in 129 patients. This resulted in 31 variants of which 11 were (likely) pathogenic. (Likely) pathogenic variants resulted in 3 groups based on disease association: ALS-FTD (C9orf72, TBK1), pure HSP (SPAST, SPG7), "ALS-HSP-CMT overlap" (FIG4, NEFL, SPG11).

DISCUSSION

In a cohort of 139 PLS patients, genetic analyses resulted in 31 variants (22%) of which 10 (7%) (likely) pathogenic associated with different diseases (predominantly ALS and HSP). Based on these results and the literature, we advise to consider genetic analyses in the diagnostic work-up for PLS.

Diagnosis across a cohort of "atypical" atypical and complex parkinsonism

INTRODUCTION

The diagnostic approach for adulthood parkinsonism can be challenging when atypical features hamper its classification in one of the two main parkinsonian groups: Parkinson's disease or atypical parkinsonian syndromes (APS). Atypical features are usually associated with non-sporadic neurodegenerative causes.

METHODS

Retrospective analysis of patients with a working clinical diagnosis of "atypical" APS and complex parkinsonism. "Atypical" APS were classified according to the diagnostic research criteria and the "4-step diagnostic approach" (Stamelou et al. 2013). When not indicated, the final aetiological diagnosis was prospectively assessed. Brain MRI of progressive supranuclear palsy (PSP) look-alikes was reviewed by a neuroradiologist.

RESULTS

Among 18 patients enrolled, ten were assigned to the "atypical" APS and eight to the complex parkinsonism group. In the "atypical" APS group, nine patients had PSP and one had corticobasal degeneration. In the PSP group the median magnetic resonance parkinsonism index was 17.1. A final aetiological diagnosis was established for 11 patients, four from the complex parkinsonism (L-2-hidroxiglutaric aciduria and DiGeorge syndrome) and seven from the "atypical" APS (Perry syndrome, postencephalitic PSP, vascular PSP, and MTP-AT6 mitochondrial disease) group.

CONCLUSIONS

In this study, the identification of atypical APS features, as proposed in the "4-step diagnostic approach", successfully guided the investigation of alternative diagnoses. Distinctive non-neurodegenerative etiologies causing "atypical" atypical and complex parkinsonism were uncovered, including acquired (post-encephalitis and vascular) and genetic (MTP-AT6 mitochondrial disease mimicking PSP, described for the first time) ones. In the future, accurate clinical identification and distinction between neurodegenerative and non-neurodegenerative parkinsonism etiologies will allow for refining clinical trials.

The Use of Cerebellar Hypoperfusion Assessment in the Differential Diagnosis of Multiple System Atrophy with Parkinsonism and Progressive Supranuclear Palsy-Parkinsonism Predominant

The differential diagnosis of MSA-P and PSP-P remains a difficult issue in clinical practice due to their overlapping clinical manifestation and the lack of tools enabling a definite diagnosis ante-mortem. This paper describes the usefulness of SPECT HMPAO in MSA-P and PSP-P differentiation through the analysis of cerebellar perfusion of small ROIs. Thirty-one patients were included in the study—20 with MSA-P and 11 with PSP-P; the analysis performed indicated that the most significant difference in perfusion was observed in the anterior quadrangular lobule (H IV and V) on the left side (p < 0.0026). High differences in the median perfusion between the groups were also observed in a few other regions, with p < 0.05, but higher than premised p = 0.0026 (the Bonferroni correction was used in the statistical analysis). The assessment of the perfusion may be interpreted as a promising method of additional examination of atypical parkinsonisms with overlapping clinical manifestation, as in the case of PSP-P and MSA-P. The results obtained suggest that the interpretation of the differences in perfusion of the cerebellum should be made by evaluating the subregions of the cerebellum rather than the hemispheres. Further research is required.

The influence of 17q21.31 and APOE genetic ancestry on neurodegenerative disease risk

Advances in genomic research over the last two decades have greatly enhanced our knowledge concerning the genetic landscape and pathophysiological processes involved in multiple neurodegenerative diseases. However, current insights arise almost exclusively from studies on individuals of European ancestry. Despite this, studies have revealed that genetic variation differentially impacts risk for, and clinical presentation of neurodegenerative disease in non-European populations, conveying the importance of ancestry in predicting disease risk and understanding the biological mechanisms contributing to neurodegeneration. We review the genetic influence of two important disease-associated loci, 17q21.31 (the "MAPT locus") and APOE, to neurodegenerative disease risk in non-European populations, touching on global population differences and evolutionary genetics by ancestry that may underlie some of these differences. We conclude there is a need to increase representation of non-European ancestry individuals in genome-wide association studies (GWAS) and biomarker analyses in order to help resolve existing disparities in understanding risk for, diagnosis of, and treatment for neurodegenerative diseases in diverse populations.

Neuroinflammation in Vascular Cognitive Impairment and Dementia: Current Evidence, Advances, and Prospects

Vascular cognitive impairment and dementia (VCID) is a major heterogeneous brain disease caused by multiple factors, and it is the second most common type of dementia in the world. It is caused by long-term chronic low perfusion in the whole brain or local brain area, and it eventually develops into severe cognitive dysfunction syndrome. Because of the disease’s ambiguous classification and diagnostic criteria, there is no clear treatment strategy for VCID, and the association between cerebrovascular pathology and cognitive impairment is controversial. Neuroinflammation is an immunological cascade reaction mediated by glial cells in the central nervous system where innate immunity resides. Inflammatory reactions could be triggered by various damaging events, including hypoxia, ischemia, and infection. Long-term chronic hypoperfusion-induced ischemia and hypoxia can overactivate neuroinflammation, causing apoptosis, blood–brain barrier damage and other pathological changes, triggering or aggravating the occurrence and development of VCID. In this review, we will explore the mechanisms of neuroinflammation induced by ischemia and hypoxia caused by chronic hypoperfusion and emphasize the important role of neuroinflammation in the development of VCID from the perspective of immune cells, immune mediators and immune signaling pathways, so as to provide valuable ideas for the prevention and treatment of the disease.

TGF-β as a Key Modulator of Astrocyte Reactivity: Disease Relevance and Therapeutic Implications

Astrocytes are essential for normal brain development and functioning. They respond to brain injury and disease through a process referred to as reactive astrogliosis, where the reactivity is highly heterogenous and context-dependent. Reactive astrocytes are active contributors to brain pathology and can exert beneficial, detrimental, or mixed effects following brain insults. Transforming growth factor-β (TGF-β) has been identified as one of the key factors regulating astrocyte reactivity. The genetic and pharmacological manipulation of the TGF-β signaling pathway in animal models of central nervous system (CNS) injury and disease alters pathological and functional outcomes. This review aims to provide recent understanding regarding astrocyte reactivity and TGF-β signaling in brain injury, aging, and neurodegeneration. Further, it explores how TGF-β signaling modulates astrocyte reactivity and function in the context of CNS disease and injury.