Progressive supranuclear palsy: new concepts

Role of long non-coding RNAs in the pathophysiology of Alzheimer's disease and other dementias

Dementia is the term used to describe a group of cognitive disorders characterized by a decline in memory, thinking, and reasoning abilities that interfere with daily life activities. Examples of dementia include Alzheimer's Disease (AD), Frontotemporal dementia (FTD), Amyotrophic lateral sclerosis (ALS), Vascular dementia (VaD) and Progressive supranuclear palsy (PSP). AD is the most common form of dementia. The hallmark pathology of AD includes formation of β-amyloid (Aβ) oligomers and tau hyperphosphorylation in the brain, which induces neuroinflammation, oxidative stress, synaptic dysfunction, and neuronal apoptosis. Emerging studies have associated long non-coding RNAs (lncRNAs) with the pathogenesis and progression of the neurodegenerative diseases. LncRNAs are defined as RNAs longer than 200 nucleotides that lack the ability to encode functional proteins. LncRNAs play crucial roles in numerous biological functions for their ability to interact with different molecules, such as proteins and microRNAs, and subsequently regulate the expression of their target genes at transcriptional and post-transcriptional levels. In this narrative review, we report the function and mechanisms of action of lncRNAs found to be deregulated in different types of dementia, with the focus on AD. Finally, we discuss the emerging role of lncRNAs as biomarkers of dementias.

Quantitative susceptibility mapping from basal ganglia and related structures: correlation with disease severity in progressive supranuclear palsy

OBJECTIVE

We examined whether mean magnetic susceptibility values from deep gray matter structures in patients with progressive supranuclear palsy (PSP) differed from those in patients with Parkinson's disease (PD) and healthy volunteers, and correlated with the PSP rating scale.

METHODS

Head of caudate nucleus, putamen, globus pallidus, substantia nigra and red nucleus were the regions of interest. Mean susceptibility values from these regions in PSP patients were estimated using quantitative susceptibility mapping. Correlations with clinical severity of disease as measured by the PSP rating scale were examined. The mean susceptibility values were also compared with those from healthy volunteers and age- and disease duration-matched patients with PD.

RESULTS

Data from 26 healthy volunteers, 26 patients with PD and 27 patients with PSP, were analysed. Patients with PSP had higher mean susceptibility values from all regions of interest when compared to both the other groups. The PSP rating scale scores correlated strongly with mean susceptibility values from the red nucleus and moderately with those from the putamen and substantia nigra. The scores did not correlate with mean susceptibility values from the caudate nucleus or globus pallidus. In patients with PD, the motor deficits correlated moderately with mean susceptibility values from substantia nigra.

CONCLUSIONS

In patients with PSP, mean susceptibility values indicating the severity of mineralization of basal ganglia and related structures correlate with disease severity, the correlation of red nucleus being the strongest. Further studies are warranted to explore whether mean susceptibility values could serve as biomarkers for PSP.

Physiotherapy case reports on three people with progressive supranuclear palsy

Introduction

Progressive supranuclear palsy (PSP) is a neurodegenerative brain disease that affects patient's functionality and quality of life. Physiotherapy should be recommended at the time of diagnosis to slow the progression of disability and enhance the quality of life of these patients.

Clinical presentation

Here, we describe three cases of patients with PSP, outlining their motor and non-motor symptoms and examining their clinical progression with physiotherapy intervention. During the initial intervention years, a reduction in the number of falls was achieved, along with improvements in gait and balance.

Conclusion

Exercise and physiotherapy appear to be beneficial for patients with PSP by enhancing their functionality and quality of life. Controlling or reducing the number of falls should be the primary goal of any intervention for patients with PSP.

Visual fixation suppression of caloric nystagmus in progressive supranuclear palsy - A comparison with Parkinson's disease

BACKGROUND

Impairment of visual fixation suppression (VS) in progressive supranuclear palsy (PSP) is not well documented.

OBJECTIVE

To evaluate the usefulness of impaired VS of caloric nystagmus as an index for differential diagnosis between PSP and Parkinson's disease (PD), which is often difficult, especially in the early stage.

METHODS

Subjects comprised 26 PSP patients and 26 PD patients clinically diagnosed at Tokyo Metropolitan Neurological Hospital. We retrospectively investigated VS of caloric nystagmus, horizontal pursuit, saccades, and horizontal optokinetic nystagmus recorded on direct-current-electronystagmography, and neuroradiological findings.

RESULTS

The median of the average VS% was 0% and 50.0% in PSP and PD patients, respectively. In PSP, VS was impaired even in the early stage of disease. We found a significant correlation between VS and velocity of saccades or maximum slow phase velocity of optokinetic nystagmus only in PSP patients. PSP patients with atrophy of the subthalamic nucleus or with decreased blood flow in the frontal lobe showed significantly more severe impairment of VS.

CONCLUSIONS

VS may be a useful biomarker to differentiate patients with PSP from those with PD. Cerebellar networks that connect with the cerebral cortex and basal ganglia may contribute to impaired VS of caloric nystagmus in PSP.

Parkinson's Disease: A Review from Pathophysiology to Treatment

Parkinson's Disease (PD) is the second most common neurodegenerative disease in the elderly population, with a higher prevalence in men, independent of race and social class; it affects approximately 1.5 to 2.0% of the elderly population over 60 years and 4% for those over 80 years of age. PD is caused by the necrosis of dopaminergic neurons in the substantia nigra, which is the brain region responsible for the synthesis of the neurotransmitter dopamine (DA), resulting in its decrease in the synaptic cleft. The monoamine oxidase B (MAO-B) degrades dopamine, promoting the glutamate accumulation and oxidative stress with the release of free radicals, causing excitotoxicity. The PD symptoms are progressive physical limitations such as rigidity, bradykinesia, tremor, postural instability and disability in functional performance. Considering that there are no laboratory tests, biomarkers or imaging studies to confirm the disease, the diagnosis of PD is made by analyzing the motor features. There is no cure for PD, and the pharmacological treatment consists of a dopaminergic supplement with levodopa, COMT inhibitors, anticholinergics agents, dopaminergic agonists, and inhibitors of MAO-B, which basically aims to control the symptoms, enabling better functional mobility and increasing life expectancy of the treated PD patients. Due to the importance and increasing prevalence of PD in the world, this study reviews information on the pathophysiology, symptomatology as well as the most current and relevant treatments of PD patients.

Falls in Progressive Supranuclear Palsy

BACKGROUND

Despite falls being an almost universal clinical feature and central to the presentation and diagnostic criteria of progressive supranuclear palsy, our understanding of falls is surprisingly limited and there are few effective treatment options.

OBJECTIVES

To provide an overview of the topic of the impact, assessment, mechanism, and management of falls in progressive supranuclear palsy.

METHODS

We performed a literature search for "falls" and "progressive supranuclear palsy" and included additional relevant literature known to us. We synthesized this literature with experience from clinical practice.

RESULTS

We review current understanding of the pathophysiology of falls, highlighting the roles of the indirect pathway and the pedunculopontine nucleus. We go on to identify shortcomings in commonly used assessments to measure falls. We discuss medical and nonmedical fall prevention strategies, and finally we discuss balancing falls risk against promoting independence.

CONCLUSION

Falls are central to progressive supranuclear palsy presentation and diagnosis. Indirect locomotor and pedunculopontine nucleus dysfunction are thought to be the neural substrate of falls in this condition. Attempts to measure and prevent falls, by medical and nonmedical means, are currently limited. A personalized approach is advocated in the management of falls.

The combination of short-step and wide-based gait is a gait characteristic in progressive supranuclear palsy: a retrospective, cross-sectional study

PURPOSE

Like Parkinson's disease (PD), gait disturbance is a major problem in progressive supranuclear palsy (PSP). Despite limited studies investigating the gait characteristics, we hypothesize that they differ from PD owing to the involvement of different brain lesions. Hence, this study aims to investigate the gait characteristics in patients with PSP by comparing with healthy older adults and patients with PD.

METHODS

We identified 27 PSP patients, 25 PD patients, and 25 neurologically healthy older persons. Using a device that detected the distribution of foot pressure during walking, we analyzed gait variables and measured the walking speed (cm/s), cadence (steps/min), step length (cm), step width (cm), foot angle (°), and gait cycle time (s). Additionally, we calculated the coefficient of variation (CV, %) on walking speed and cadence and analyzed the gait characteristics by the PSP subtypes.

RESULTS

In PSP and PD, the walking speed was slower and the step length was shorter than healthy controls. The CV of cadence in PSP was higher than healthy controls and PD. In PSP, the step width and foot angle were higher than healthy controls and PD. The gait cycle time was longer in PSP and PD than healthy controls. PSP with progressive freezing gait tended to display a faster walking speed. Furthermore, PSP with parkinsonism-resembling idiopathic PD tended to exhibit the larger step width and foot angle compared with PSP-Richardson's syndrome.

CONCLUSION

This study suggests that the gait of PSP was unstable with parkinsonism and wide-based, which might be similar to combining features of PD and cerebellar disorders.

Progressive supranuclear palsy responding to intravenous thiamine: superimposed Wernicke's encephalopathy?

Progressive supranuclear palsy (PSP) may be a risk factor for thiamine deficiency. The classic symptoms of PSP (postural instability, supranuclear vertical gaze palsy and dementia) overlap with the clinical triad of Wernicke's encephalopathy (cognitive impairment, gait problems and ocular abnormality). Therefore, superimposed thiamine deficiency in patients with PSP may aggravate the pre-existing symptoms of PSP. Here, we are reporting a 64-year-old woman having supranuclear ocular palsy, gait instability and dementia for the past 2-3 years. The patient fulfilled the diagnostic criteria of PSP. In parallel, she fulfilled the Caine's criteria of Wernicke's encephalopathy. Her serum thiamine level was low. Supplementation of thiamine led to marked improvement in the symptoms which had been present for many years. These symptoms were originally presumed to be due to PSP. This case highlights the needs to identify superimposed thiamine deficiency in patients with PSP.

Understanding falls in progressive supranuclear palsy

INTRODUCTION

Progressive supranuclear palsy (PSP) is characterized by frequent falls which worsen with disease progression, causing substantial morbidity and mortality. Few studies have investigated which factors contribute to falls in PSP, and all have involved few participants, thus lacking necessary statistical power. The aim of this study was to identify clinical parameters most significantly associated with increasing falls in PSP, using the largest sample of patients to date.

METHODS

Comprehensive clinical data were collected from 339 not demented PSP patients meeting the NINDS-SPSP criteria, who were divided into two groups - Infrequent Fallers (IF; n = 118) with rare falls, and Frequent Fallers (FF; n = 221) who fell occasionally to multiple times a day. Of 198 clinical parameters, we hypothesized 38 to be correlated with an increasing risk of falls. These 38 parameters were analyzed via univariate regression analysis to determine the strength of their association with fall frequency. Unit odds ratios identified the magnitude with which each parameter resulted in an increasing risk of falls.

RESULTS

Twenty-five of 38 parameters analyzed were significantly associated with fall frequency based on univariate analysis. Symptom duration, clinical measures of disease severity, and several motoric and oculomotor clinical parameters were associated with FF. Examined cognitive parameters and slowing of vertical saccades were not.

CONCLUSIONS

The clinical parameters identified as associated with increased frequency of falls improve our understanding of why they occur and may help identify not demented PSP patients at risk for increasing falls.

Cerebellar ataxia in progressive supranuclear palsy: An autopsy study of PSP-C

BACKGROUND

Cerebellar ataxia is an exclusion criterion for the clinical diagnosis of progressive supranuclear palsy, but a variant with predominant cerebellar ataxia has been reported. The aims of this study were to estimate the frequency of progressive supranuclear palsy with predominant cerebellar ataxia in an autopsy series from the United States and to compare clinical, pathologic, and genetic differences between progressive supranuclear palsy with and without predominant cerebellar ataxia.

METHOD

We selected 100 consecutive patients with pathologically confirmed progressive supranuclear palsy who had been evaluated at the Mayo Clinic (referred to as the Mayo Clinic patient series) from our brain bank database (N = 1085). We next enriched in cases likely to have cerebellar ataxia by searching the remaining 985 cases for (1) an antemortem diagnosis of multiple system atrophy or (2) neuropathologic evidence of prominent degeneration of the cerebellum or cerebellar afferent nuclei. Subsequently, clinical, pathologic, and genetic features were compared between the two groups.

RESULTS

One patient in the Mayo Clinic patient series (1%) met criteria for progressive supranuclear palsy with predominant cerebellar ataxia and had both cerebellar and mild midbrain atrophy on MRI. Four patients were identified with the targeted search. Four of the five patients were clinically misdiagnosed as multiple system atrophy. The severity of tau-related pathology and cerebellar degeneration were not different between the two groups. No differences were detected in tau genotypes.

CONCLUSION

Although our data cannot provide definitive information about how to make an accurate clinical diagnosis, they should serve to raise awareness of progressive supranuclear palsy with predominant cerebellar ataxia in the differential diagnosis of multiple system atrophy. © 2016 Movement Disorder Society.

The role of neuroimaging in the diagnosis of the atypical parkinsonian syndromes in clinical practice

Atypical parkinsonian disorders (APD) are a heterogenous group of neurodegenerative diseases such as: progressive supranuclear palsy (PSP), multiple system atrophy (MSA), cortico-basal degeneration (CBD) and dementia with Lewy bodies (DLB). In all of them core symptoms of parkinsonian syndrome are accompanied by many additional clinical features not typical for idiopathic Parkinson's disease (PD) like rapid progression, gaze palsy, apraxia, ataxia, early cognitive decline, dysautonomia and usually poor response to levodopa therapy. In the absence of reliably validated biomarkers the diagnosis is still challenging and mainly based on clinical criteria. However, robust data emerging from routine magnetic resonance imaging (MRI) as well as from many advanced MRI techniques such as: diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI), magnetic resonance spectroscopy (MRS), voxel-based morphometry (VBM), susceptibility-weighted imaging (SWI) may help in differential diagnosis. The main aim of this review is to summarize briefly the most important and acknowledged radiological findings of conventional MRI due to its availability in standard clinical settings. Nevertheless, we present shortly other methods of structural (like TCS - transcranial sonography) and functional imaging (like SPECT - single photon emission computed tomography or PET - positron emission tomography) as well as some selected advanced MRI techniques and their potential future applications in supportive role in distinguishing APD.

Voxelwise meta-analysis of gray matter anomalies in progressive supranuclear palsy and Parkinson's disease using anatomic likelihood estimation

Numerous voxel-based morphometry (VBM) studies on gray matter (GM) of patients with progressive supranuclear palsy (PSP) and Parkinson's disease (PD) have been conducted separately. Identifying the different neuroanatomical changes in GM resulting from PSP and PD through meta-analysis will aid the differential diagnosis of PSP and PD. In this study, a systematic review of VBM studies of patients with PSP and PD relative to healthy control (HC) in the Embase and PubMed databases from January 1995 to April 2013 was conducted. The anatomical distribution of the coordinates of GM differences was meta-analyzed using anatomical likelihood estimation. Separate maps of GM changes were constructed and subtraction meta-analysis was performed to explore the differences in GM abnormalities between PSP and PD. Nine PSP studies and 24 PD studies were included. GM reductions were present in the bilateral thalamus, basal ganglia, midbrain, insular cortex and inferior frontal gyrus, and left precentral gyrus and anterior cingulate gyrus in PSP. Atrophy of GM was concentrated in the bilateral middle and inferior frontal gyrus, precuneus, left precentral gyrus, middle temporal gyrus, right superior parietal lobule, and right cuneus in PD. Subtraction meta-analysis indicated that GM volume was lesser in the bilateral midbrain, thalamus, and insula in PSP compared with that in PD. Our meta-analysis indicated that PSP and PD shared a similar distribution of neuroanatomical changes in the frontal lobe, including inferior frontal gyrus and precentral gyrus, and that atrophy of the midbrain, thalamus, and insula are neuroanatomical markers for differentiating PSP from PD.

Early clinical features of patients with progressive supranuclear palsy with predominant cerebellar ataxia

BACKGROUND

Patients who develop progressive supranuclear palsy with predominant cerebellar ataxia (PSP-C) develop cerebellar ataxia as the initial and principal symptom, may be misdiagnosed as having multiple system atrophy with predominant cerebellar features (MSA-C). Therefore, we investigated the clinical signs and symptoms between PSP-C and MSA-C early in their disease course.

METHODS

We reviewed the medical records of 15 consecutive patients with pathologically proven PSP-C (4) and MSA-C (11). We recorded the presence or absence of clinical features that developed within 2 years of disease onset.

RESULTS

The age at onset of PSP-C patients was older than that of MSA-C patients (p = 0.009). The frequencies of falls were higher in PSP-C patients than in MSA-C patients (p = 0.026). Additionally, the development of supranuclear vertical gaze palsy was higher in PSP-C patients than in MSA-C patients (p = 0.011), whereas the frequency of dysautonomia was lower in PSP-C patients than in MSA-C patients (p = 0.035).

CONCLUSIONS

Older onset, early falls, and supranuclear vertical gaze palsy without dysautonomia may predict the diagnosis of PSP-C in patients with late-onset sporadic cerebellar ataxia.

Electrophysiological features of lower motor neuron involvement in progressive supranuclear palsy

BACKGROUND

Abnormalities of the spinal cord were considered uncommon in progressive supranuclear palsy (PSP), and therefore spinal symptoms were not included among PSP characteristic features. However there have been some neuropathological reports of spinal cord lesions in patients with PSP. The aim of our study was to find out if the possible lower motor neuron involvement in PSP is reflected by electromyographic (EMG) and/or electroneurographic (ENG) abnormalities.

MATERIAL

24 patients with clinically probable PSP (mean age 67.5 yrs; 66% males) were included in the study. The control group for ENG studies consisted 25 age matched healthy volunteers.

METHODS

Nerve conduction studies in the ulnar, peroneal and sural nerves and EMG of the first interosseus dorsal and tibial anterior muscles were performed.

RESULTS

The only ENG abnormality observed was decreased compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes in the ulnar nerve. Such decrease was registered in 8.3% and 20% of PSP patients respectively. There was no significant difference between the values of ENG parameters between PSP patients and the control group. In EMG abnormalities suggesting chronic reinnervation were recorded in the first interosseous dorsal (FID) muscle in 45.8%, and in the tibialis anterior (TA) muscle in 37.5% of PSP patients. A significant correlation was found between the age of PSP patients and their mean motor unit potential (MUP) amplitude in TA muscle (p=0.04) and also between the age of onset and MUP amplitude in both, the TA and FID muscles (p=0.026 and p=0.03 respectively).

CONCLUSIONS

In PSP, neurogenic EMG abnormalities in skeletal muscles are present in nearly half the patients suggesting a loss of motor neurons in the anterior horns of the spinal cord which is in line with our histopathological findings. In contrast, electrophysiological signs of neuropathy in peripheral nerves in PSP are very rare. Concluding, although PSP is characterized by the pathological process in specific basal ganglia and brainstem areas, our electromyographic study suggests the need for broadening the spectrum of PSP for lower motor neurons degeneration.

Treatment options for tauopathies

OPINION STATEMENT

To date, there are no approved and established pharmacologic treatment options for tauopathies, a very heterogenous group of neuropsychiatric diseases often leading to dementia and clinically diagnosed as atypical Parkinson syndromes. Among these so-called Parkinson plus syndromes are progressive supranuclear palsy (PSP), also referred to as Steele-Richardson-Olszewski syndrome; frontotemporal dementia (FTD); and corticobasal degeneration (CBD). Available treatment strategies are based mainly on small clinical trials, miscellaneous case reports, or small case-controlled studies. The results of these studies and conclusions about the efficacy of the medication used are often contradictory. Approved therapeutic agents for Alzheimer´s dementia, such as acetylcholinesterase inhibitors and memantine, have been used off-label to treat cognitive and behavioral symptoms in tauopathies, but the outcome has not been consistent. Therapeutic agents for the symptomatic treatment of Parkinson's disease (levodopa or dopamine agonists) are used for motor symptoms in tauopathies. For behavioral or psychopathological symptoms, treatment with antidepressants-especially selective serotonin reuptake inhibitors-could be helpful. Antipsychotics are often not well tolerated because of their adverse effects, which are pronounced in tauopathies; these drugs should be given very carefully because of an increased risk of cerebrovascular events. In addition to pharmacologic options, physical, occupational, or speech therapy can be applied to improve functional abilities. Each pharmacologic or nonpharmacologic intervention should be fitted to the specific symptoms of the individual patient, and decisions about the type and duration of treatment should be based on its efficacy for the individual and the patient's tolerance. Currently, no effective treatment is available that targets the cause of these diseases. Current research focuses on targeting tau protein pathology, including pathologic aggregation or phosphorylation; these approaches seem to be very promising.

Cuidados odontológicos na paralisia supranuclear progressiva: relato de caso

Este trabalho teve como objetivo relatar o tratamento de complicações bucais numa paciente hospitalizada com diagnóstico de paralisia supranuclear progressiva (PSP), causa mais comum de parkinsonismo degenerativo. A paciente fazia uso de vários medicamentos, tinha 70 anos de idade, sem acompanhamento odontológico durante a hospitalização, com edentulismo total na arcada superior e usuária de prótese parcial na região inferior, mas em função do quadro clínico sistêmico não fazia uso da mesma. No exame bucal, constatou-se uma lesão na mucosa e lábio superior em decorrência de trauma dos dentes inferiores. Planejou-se inicialmente o tratamento da lesão com laserterapia e exodontias dos dentes que provocaram a lesão traumática. Após a cicatrização da lesão, os dentes inferiores remanescentes foram extraídos. Os resultados obtidos da terapêutica aplicada foram eficazes na melhora clínica da paciente. Conclui-se, assim, que é marcante a necessidade de um cirurgião-dentista como membro permanente da equipe multidisciplinar para o tratamento dessa e de outras patologias, a fim de permitir melhor qualidade de vida aos pacientes.