Progressive supranuclear palsy: a current review

Concerning neuromodulation as treatment of neurological and neuropsychiatric disorder: Insights gained from selective targeting of the subthalamic nucleus, para-subthalamic nucleus and zona incerta in rodents

Neuromodulation such as deep brain stimulation (DBS) is advancing as a clinical intervention in several neurological and neuropsychiatric disorders, including Parkinson's disease, dystonia, tremor, and obsessive-compulsive disorder (OCD) for which DBS is already applied to alleviate severely afflicted individuals of symptoms. Tourette syndrome and drug addiction are two additional disorders for which DBS is in trial or proposed as treatment. However, some major remaining obstacles prevent this intervention from reaching its full therapeutic potential. Side-effects have been reported, and not all DBS-treated individuals are relieved of their symptoms. One major target area for DBS electrodes is the subthalamic nucleus (STN) which plays important roles in motor, affective and associative functions, with impact on for example movement, motivation, impulsivity, compulsivity, as well as both reward and aversion. The multifunctionality of the STN is complex. Decoding the anatomical-functional organization of the STN could enhance strategic targeting in human patients. The STN is located in close proximity to zona incerta (ZI) and the para-subthalamic nucleus (pSTN). Together, the STN, pSTN and ZI form a highly heterogeneous and clinically important brain area. Rodent-based experimental studies, including opto- and chemogenetics as well as viral-genetic tract tracings, provide unique insight into complex neuronal circuitries and their impact on behavior with high spatial and temporal precision. This research field has advanced tremendously over the past few years. Here, we provide an inclusive review of current literature in the pre-clinical research fields centered around STN, pSTN and ZI in laboratory mice and rats; the three highly heterogeneous and enigmatic structures brought together in the context of relevance for treatment strategies. Specific emphasis is placed on methods of manipulation and behavioral impact.

Progressive supranuclear palsy: A case report and brief review of the literature

Atypical Parkinsonian syndromes are a subset of progressive neurodegenerative disorders that present with signs of Parkinson's disease. However, due to multisystem degeneration, the atypical Parkinsonian syndromes have additional symptoms that are often referred to as Parkinson-plus syndromes. The most well-studied subsets include progressive supranuclear palsy (PSP), multiple system atrophy (MSA), corticobasal degeneration (CBD), and Lewy body dementia. Specifically, progressive supranuclear palsy is a tauopathy neurodegenerative disorder that presents with parkinsonism symptoms along with postural instability, vertical saccade, and vertical gaze palsy. Here, we present a case of PSP and provide a brief review of the literature.

Quantifying Impairments in Swallowing Safety and Efficiency in Progressive Supranuclear Palsy and Parkinson's Disease

Dysphagia is a largely inevitable symptom in both progressive supranuclear palsy (PSP) and Parkinson's disease (PD). To date, comparative studies in these diseases have failed to detect differences in the severity of impairments in swallowing safety or efficiency, potentially due to small sample sizes and outcome measures with low sensitivity. Therefore, this study sought to address these limitations by using novel measurement methodology to comprehensively compare swallowing safety and efficiency impairments between these populations in order to better understand whether differences may exist and guide clinical management. Twenty-four participants with PSP and 24 with PD were matched for disease duration and completed flexible endoscopic evaluations of swallowing. A visual analog scale and penetration-aspiration scale quantified swallowing safety and efficiency. Bayesian multilevel models compared the frequency, severity, and variability of swallowing impairments. Individuals with PSP demonstrated greater impairments in swallowing safety, including deeper and more variable airway invasion and more frequent vocal fold and subglottic residue. Swallowing efficiency was also more impaired among individuals with PSP, including more frequent hypopharyngeal residue (with solids) and more severe residue in the oropharynx (with thin liquids and solids) and hypopharynx (with thin liquids). When airway or pharyngeal residue was present, similar within-subject variability of the amount of residue was appreciated across anatomic landmarks. This is the first study comparing the frequency, severity, and variability of swallowing impairments between PSP and PD populations. Our findings demonstrate more pronounced impairments in swallowing safety and efficiency for PSP compared to PD. These findings provide a clinically relevant characterization of swallowing measures using novel methodological and statistical approaches attempting to resolve some limitations of prior studies.

Training high level balance and stepping responses in atypical progressive supranuclear palsy: a case report

BACKGROUND

Progressive supranuclear palsy (PSP) is a neurodegenerative condition, typically presenting with, but not limited to, impairments of postural instability, gait, and gaze stability.

PURPOSE

This case report describes the multifactorial assessment and rehabilitation of a patient with atypical PSP who has significant gaze deficits, asymmetrical stepping responses, trunk rigidity, and reduced posterior excursion on limits of stability.

CASE DESCRIPTION

Evaluation utilized computerized gait and balance assessments, foot clearance analysis, a squat test, and a timed stepping test. The intervention included boxing, stepping tasks, and treadmill training each with eye movement challenges. A total of 15 hours of physical therapy was provided; 1 hour, 2 times a week.

OUTCOMES

Post-intervention improvements were noted subjectively, on eye-body coordination, and objectively, on limits of stability, foot clearance, and task performance (squats, timed stepping). Follow-up demonstrated some decline from posttest results; however, patient-reported adherence to the program was less than recommended.

CONCLUSION

A multifactorial rehabilitation program can improve balance, eye-body coordination, and strength in a high functioning patient with atypical PSP. Longitudinal randomized controlled studies are suggested to further investigate this interventional approach in high functioning individuals diagnosed with atypical PSP.

Mass spectrometry-based proteomics analysis of human globus pallidus from progressive supranuclear palsy patients discovers multiple disease pathways

BACKGROUND

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder clinically characterized by progressive postural instability, supranuclear gaze palsy, parkinsonism, and cognitive decline caused by degeneration in specific areas of the brain including globus pallidus (GP), substantia nigra, and subthalamic nucleus. However, the pathogenetic mechanism of PSP remains unclear to date.Unbiased global proteome analysis of patients' brain samples is an important step toward understanding PSP pathogenesis, as proteins serve as workhorses and building blocks of the cell.

METHODS

In this study, we conducted unbiased mass spectrometry-based global proteome analysis of GP samples from 15 PSP patients, 15 Parkinson disease (PD) patients, and 15 healthy control (HC) individuals. To analyze 45 samples, we conducted 5 batches of 11-plex isobaric tandem mass tag (TMT)-based multiplexing experiments. The identified proteins were subjected to statistical analysis, such as a permutation-based statistical analysis in the significance analysis of microarray (SAM) method and bootstrap receiver operating characteristic curve (ROC)-based statistical analysis. Subsequently, we conducted bioinformatics analyses using gene set enrichment analysis, Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) protein-protein interaction (PPI) analysis, and weighted gene co-expression network analysis (WGCNA).

RESULTS

We have identified 10,231 proteins with ∼1,000 differentially expressed proteins. The gene set enrichment analysis results showed that the PD pathway was the most highly enriched, followed by pathways for oxidative phosphorylation, Alzheimer disease, Huntington disease, and non-alcoholic fatty liver disease (NAFLD) when PSP was compared to HC or PD. Most of the proteins enriched in the gene set enrichment analysis were mitochondrial proteins such as cytochrome c oxidase, NADH dehydrogenase, acyl carrier protein, succinate dehydrogenase, ADP/ATP translocase, cytochrome b-c1 complex, and/or ATP synthase. Strikingly, all of the enriched mitochondrial proteins in the PD pathway were downregulated in PSP compared to both HC and PD. The subsequent STRING PPI analysis and the WGCNA further supported that the mitochondrial proteins were the most highly enriched in PSP.

CONCLUSION

Our study showed that the mitochondrial respiratory electron transport chain complex was the key proteins that were dysregulated in GP of PSP, suggesting that the mitochondrial respiratory electron transport chain complex could potentially be involved in the pathogenesis of PSP. This is the first global proteome analysis of human GP from PSP patients, and this study paves the way to understanding the mechanistic pathogenesis of PSP.

Association of Progressive Supranuclear Palsy Rating Scale with Progressive Supranuclear Palsy Quality of Life Scale

INTRODUCTION

There 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.

METHODS

PSP-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.

RESULTS

Among 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.

DISCUSSION

There 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.

Hypertension and progressive supranuclear palsy

BACKGROUND

The epidemiologic evidence of whether hypertension is associated with Progressive Supranuclear Palsy (PSP) is inconsistent. The ENGENE-PSP case-control study determined various PSP risk factors including whether hypertension preceded PSP onset.

METHODS

Incident PSP cases per NINDS-PSP criteria and age-, sex-, race- matched controls were recruited from similar North American geographic areas. All study participants were administered standardized interviews to obtain data on demographics, medical history and medications.

STATISTICS

We used univariate and multivariate conditional logistic regression models to measure the associations between PSP and the following predictor variables: education level, hypertension, comorbid vascular conditions (diabetes mellitus and hyperlipidemia), and classes of anti-hypertensive medications using odds ratios and 95% confidence intervals.

RESULTS

There were significant associations seen between PSP and hypertension (OR: 1.569; 95% CI 1.129-2.181; p-value = 0.007), education level (OR: 0.733; 95% CI 0.637-0.843; p-value<0.001) and beta-blocker use (OR: 2.000; 95% CI 1.053-3.799; p-value = 0.034). However, in the multi-variate analysis hypertension (OR: 1.492; 95% CI 1.045-2.129; p-value = 0.027) and education level (OR: 0.730; 95% CI 0.633-0.841; p-value<0.001) were the only significant associations.

CONCLUSION

These results suggest that there is a modest, yet significant association between hypertension and PSP. Further studies will be needed to better understand the pathophysiological basis for this finding.

Creutzfeldt–Jakob disease with unusual presentation of peripheral neuropathy and ophthalmoplegia

Creutzfeldt–Jakob disease (CJD) is a well-described disease. It is characterized by rapidly progressive dementia, myoclonus, ataxia, pyramidal, and extrapyramidal signs. There are well-defined electroencephalogram and magnetic resonance imaging (MRI) findings, and markers found in the cerebrospinal fluid (CSF). The gold standard for diagnosing CJD remains brain biopsy. We present a case of a patient with a family history of biopsy-proven CJD who initially presented with symptoms of peripheral neuropathy. A month later, he developed ataxia, ophthalmoparesis, and then dysarthria. His initial workup was relatively unrevealing, showing an elevated protein in his CSF. He was thought to have Miller Fisher syndrome variant of Guillain–Barré syndrome. He neither, however, responded to plasmapheresis nor IVIG. He later started to develop progressive dementia. Repeated MRI showed restricted diffusion in the caudate and putamen, as well as in the cortex (cortical ribboning). Lumbar puncture was then found to be positive for 14-3-3 protein, total-tau protein, and real-time quaking-induced conversion assay, which are highly suggestive of CJD. We present a case of CJD with an unusual presentation resulting in misdiagnosis, prolonged workup, and potentially harmful treatment modalities. This case highlights the importance of broadening our definition of CJD to encompass more cases with unusual presentations.

Planning for an uncertain future in progressive neurological disease: a qualitative study of patient and family decision-making with a focus on eating and drinking

BACKGROUND

Dysphagia and other eating and drinking difficulties are common in progressive neurological diseases. Mealtimes can become a major source of difficulty and anxiety for patients and their families. Decisions about eating, drinking and care can become challenging as disease progresses, and the person in question loses the capacity to participate in decisions about their own care. We sought to investigate how patients and their family members make decisions about their future care as their condition deteriorates, with a particular focus on mealtimes, eating and drinking.

METHODS

Longitudinal qualitative in-depth interviews were undertaken with patients and their family members (N = 29) across a range of disease groups, including: dementia, Parkinson's Disease, Huntington's Disease, Progressive Supranuclear Palsy, Motor Neurone Disease, Multiple Sclerosis. Patients had varying degrees of eating and drinking difficulties, and levels of decision-making capacity. Interviews were 'participant led' and undertaken in the patients' own homes or a place of their choosing. Follow-up interviews were three months to one year later depending upon disease trajectory. Interviews were audio recorded and analysed in NVivo using a Thematic Analysis approach.

RESULTS

Twenty-nine participants were interviewed between 2015 and 2017. Two key themes emerged from the analysis: 1) Health Literacy: the extent to which patients and relatives appeared to know about the condition and its treatment. Patients and their family members varied in their ability to speak and communicate about their condition and prognosis. 2) Planning style: the extent to which participants appeared to value involvement in advance care-planning. Patients and their family members varied in the way in which they made decisions: some preferred to 'take each day as it comes', while others wished to plan extensively for the future.

CONCLUSIONS

Issues with eating and drinking are often overlooked. Clinicians need to understand both the patient's level of health literacy and their style of planning before communicating with patients and their families about these sensitive issues.

The role of 18F-FP-CIT PET in differentiation of progressive supranuclear palsy and frontotemporal dementia in the early stage

PURPOSE

The purpose of this study was to evaluate whether the pattern of striatal dopamine transporter (DAT) availability could differentiate between progressive supranuclear palsy (PSP) and frontotemporal dementia (FTD) in the first few years of the disease.

METHODS

We enrolled patients who had Parkinsonism and frontal dysfunction and/or language deficit, visited the clinic within 2 years of the onset of symptoms, and had been followed-up for longer than 5 years; thus resulting in 26 patients with PSP and 24 patients with FTD. By quantitatively analyzing N-(3-[¹⁸F]fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) nortropane PET, we compared the pattern of DAT availability at the time of the baseline evaluation between the two groups. The discriminatory power of variables including DAT activity and clinical parameters was investigated by receiver operating characteristics (ROC) analyses. Additionally, we analyzed the correlation between striatal subregional DAT availability and cognitive profiles.

RESULTS

Patients with PSP and FTD had significantly lower DAT availability than normal controls in the whole striatum and in each striatal subregion. When comparing the two groups, DAT availability was significantly lower in patients with PSP than those with FTD in all striatal subregions. The PSP and FTD groups had generally similar subregional patterns of DAT activity in terms of the anteroposterior and ventrodorsal gradients and asymmetry, except for a different preferential involvement in the caudate. The ROC analysis showed that the DAT activity of the whole striatum had an excellent discriminatory power relative to Parkinsonism or neurocognitive profiles. Correlation analysis showed that verbal memory was significantly correlated with DAT availability in the whole striatum and the putaminal subregion only in patients with PSP.

CONCLUSIONS

DAT scans have prognostic value in determining whether patients with Parkinsonism and behavioral and/or language dysfunction will develop features of PSP or FTD later in the disease course.

Brain imaging in the differential diagnosis of young-onset dementias

Young-onset dementia is a broad category of diseases that affect adults before the age of 65, with devastating effects on individuals and families. Neuroimaging plays a clear and ever-expanding role in the workup of these diseases. MRI demonstrates classic patterns of atrophy that help to confirm the clinical diagnosis and may predict the underlying disease. Functional nuclear imaging, such as PET, demonstrates areas of brain dysfunction even in the absence of visible atrophy. These techniques can inform important aspects of the care of young-onset dementia, such as the underlying pathologic condition, treatment, and prognosis.

Discriminating features of gait performance in progressive supranuclear palsy

INTRODUCTION

Progressive supranuclear palsy (PSP) is the most common form of atypical Parkinsonism; however it is underdiagnosed and often misdiagnosed as Parkinson's disease (PD).

METHODS

We investigated gait initiation (GI) and gait performance in a total of 36 participants (12 PSP, 12 PD and 12 healthy age- and gender-matched controls) to gain further insight into specific motor deficits that characterize dynamic postural control and gait in PSP. Anticipatory postural adjustments (APAs), quantified by center of pressure (COP) displacement and speed prior to an initial heel off, and the maximum distance (COPCOM) between COP and center of mass (COM) during all three GI phases were calculated to evaluate dynamic postural control. Steady-state gait performance was also evaluated and compared across the groups.

RESULTS

APAs in PSP were significantly altered such that the posterior COP shift is profoundly diminished when compared to PD (p < 0.05). Moreover, proper velocity control during GI in PSP was affected, particularly in the mediolateral direction, when compared to PD (p < 0.05). The diminished COPCOM distance is further indicative of more severe dynamic postural instability in PSP than in PD (p < 0.05). Significant differences in spatiotemporal parameters, inter-step variability, and asymmetry during gait in PSP, in comparison with PD were also identified (all p's < 0.05).

CONCLUSION

The present study reveals that the compensatory GI strategy in PSP is distinct from PD and paradoxically induces lateral instability. Further, gait performance in PSP is slower and more variable which could be the consequence of lateral instability and fear of falling.

Gait and Computerized Dynamic Posturography (CDP) Aspects in Early Progressive Supranuclear Palsy (PSP) - A Case Report

BACKGROUND: Posture and gait instability may cause of morbidity in individuals with progressive supranuclear palsy (PSP). OBJECTIVE: To quantitatively measure balance control by using computerized dynamic posturography (CDP) and to assess gait analysis in early PSP.CASE REPORT: She was evaluated for Berge balance scale, Functional Independence Measure (FIM) and postural stability using CDP device in early PSP with still able to walk or stand unassisted. Also, Gait analysis was conducted using an 8 M-camera Vicon 612 data capturing system set. Berge balance scale improved from 41/56 to 48/56. The score of FIM improved from 71/126 points to 95/126 points in early PSP. In CDP analysis, there was a decrease of composite equilibrium score (38 %). There was an increase of composite equilibrium score (59%) after three months of treatment. In gait analysis, there was no difference of gait parameters after three months of treatment in early PSP.CONCLUSIONS: Both CDP and gait analysis are important quantitative tools in the assessment of posture and gait instability as well as allow for early disclosure of the failure of the postural control system in early PSP.

Clinical Features of Patients with Concomitant Parkinson's Disease and Progressive Supranuclear Palsy Pathology

The pathologic changes of Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP) have been reported to coexist, but whether PSP pathology modifies the clinical course of those individuals is unknown. The aim of this study was to determine whether clinical features of pathologically confirmed PD subjects with concomitant PSP pathology differ from those with PD alone. Subjects enrolled in the Arizona Study of Aging and Neurodegenerative Disorders had annual movement and cognitive evaluations from enrollment until death/autopsy. All cases between 1997 and 2014 with a final clinicopathological diagnosis of PD with or without PSP at autopsy were analyzed. Overall, 12 of the 125 cases with pathologically confirmed PD had coexisting PSP pathology (9.6%). Those with PD-PSP had more-prominent postural instability, body bradykinesia, difficulty arising from a chair, and falls; asymmetric onset was less common in this group. Downgaze palsy and square wave jerks were infrequent in both groups. Gender, age at death, disease duration, rate of dementia, and presence of rest tremor did not differ between groups. Only 58% of subjects in the PD-PSP group were correctly given a final diagnosis in life of PD, compared to 91% of those with PD alone. The combination of PD and PSP pathology yields a heterogeneous clinical syndrome that often resembles PD, but may be more symmetric at onset and have more-prominent postural instability and falls. Our observations suggest that coexisting PSP pathology may be an important factor contributing to the clinical heterogeneity in PD and a potential confounder in diagnosis.

The neurogenetics of atypical parkinsonian disorders

Although classic Parkinson disease is the disorder most commonly associated with the clinical feature of parkinsonism, there is in fact a broader spectrum of disease represented by a collection of phenotypically similar neurodegenerative conditions that mimic many of its core features. These atypical parkinsonian disorders most commonly include progressive supranuclear palsy and corticobasal degeneration, disorders both associated with frontotemporal dementia, as well as multiple system atrophy and dementia with Lewy bodies. Although the clinical distinction of these disorders still remains a challenge to physicians, recent advances in genetics are poised to tease apart the differences. Insights into the molecular etiologies underlying these conditions will improve diagnosis, yield a better understanding of the underlying disease pathology, and ultimately lend stimulation to the development of potential treatments. At the same time, the wide range of phenotypes observed from mutations in a single gene warrants broad testing facilitated by advances in DNA sequencing. These expanding genomic approaches, ranging from the use of next-generation sequencing to identify causative or risk-associated gene variations to the study of epigenetic modification linking human genetics to environmental factors, are poised to lead the field into a new age of discovery.

Effects of robot assisted gait training in progressive supranuclear palsy (PSP): a preliminary report

Background and Purpose: Progressive supranuclear palsy (PSP) is a rare neurodegenerative disease clinically characterized by prominent axial extrapyramidal motor symptoms with frequent falls. Over the last years the introduction of robotic technologies to recover lower limb function has been greatly employed in the rehabilitative practice. This observational trial is aimed at investigating the changes in the main spatiotemporal following end-effector robot training in people with PSP.

Method: Pilot observational trial.

Participants: Five cognitively intact participants with PSP and gait disorders.

Interventions: Patients were submitted to a rehabilitative program of robot-assisted walking sessions for 45 min, 5 times a week for 4 weeks.

Main outcome measures: The spatiotemporal parameters at the beginning (T0) and at the end of treatment (T1) were recorded by a gait analysis laboratory.

Results: Robot training was feasible, acceptable and safe and all participants completed the prescribed training sessions. All patients showed an improvement in the gait spatiotemporal index (Mean velocity, Cadence, Step length, and Step width) (T0 vs. T1).

Conclusions: Robot training is a feasible and safe form of rehabilitation for cognitively intact people with PSP. The lack of side effects and the positive results in the gait parameter index in all patients support the recommendation to extend the trials of this treatment. Further investigation regarding the effectiveness of robot training in time is necessary.

Trial registration: ClinicalTrials.gov NCT01668407.

Gene regulation as a potential avenue for the treatment of neurodegenerative disorders

BACKGROUND

As more people live to an older age, the frequency of diseases associated with longer life begins to increase. Neurodegenerative disorders are the worst of these in that there is now no treatment that offers any real improvement. For this reason, any new avenue of research that could lead to a treatment needs to be rigorously pursued. In many cases, neurodegenerative diseases are associated with the expression of a protein with an altered conformation or that generates a breakdown product associated with the cause. Clearly, the prevention of this process is a key therapeutic target.

OBJECTIVE

In this review, the potential for regulating gene expression to prevent or reverse neurodegenerative disease is explored.

CONCLUSIONS

Whereas much research has been directed at the proteins associated with neurodegeneration, understanding what controls their expression presents a new way this issue could be studied.

Clinical features and disability milestones in multiple system atrophy and progressive supranuclear palsy

Multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are an adult-onset progressive neurodegenerative disorder that are known to display diverse clinical features and disease progression. We aim to characterize the clinical features and disease progression in patients with MSA and PSP by using a number of relevant disability milestones in Koreans. Forty-one patients with MSA and 14 patients with PSP had been enrolled. The mean age at onset of MSA-C, MSA-P and PSP was 56.7 ± 7.8, 62.5 ± 8.0, 68.9 ± 6.1 years respectively. The most commonly reported symptom at disease onset is disequilibrium/dizziness in MSA-C, tremor in MSA-P and frequent falling in PSP. The mean duration of reaching milestones after disease onset in MSA-C were as followings: 20.8 (urinary incontinence), 22.9 (frequent falling), 27.8 (wheelchair bound), 31.8 (dysarthria) and 35.8 months (diagnosis). The mean duration of reaching milestones after disease onset were 22.0 (urinary incontinence), 32.6 (frequent falling and diagnosis), 41.2 (dysarthria), 61.4 months (wheelchair bound) in MSA-P and 16.8 (dysarthria), 21.6 (diagnosis), 21.7 (frequent falling), 24.0 months (wheel chair bound) in PSP. In the case of MSA, dizziness may occur for the first time. Thus, when the patient complains of non-specific dizziness, a follow-up examination to distinguish it from MSA can be helpful. There was a trend for patients with MSA-C to reach more disability milestones than in MSA-P and PSP before diagnosis. It may explain why patients with MSA-C are required more detail history taking and neurologic examination at an earlier stage.

Comparison of gait in progressive supranuclear palsy, Parkinson's disease and healthy older adults

Background

Progressive supranuclear palsy and Parkinson’s disease have characteristic clinical and neuropathologic profiles, but also share overlapping clinical features. This study aimed to analyze the gait of people with progressive supranuclear palsy (n=19) and compare it with people with Parkinson’s disease (n=20) and healthy older adults (n=20).

Methods

Gait was recorded at self-selected preferred, fast, very fast, slow and very slow speeds. Stride length was normalized to leg length. Linear regression analyses were carried out between cadence and stride length. Other gait variables were compared for each participant’s ‘walk’ which had stride length closest to 1.4.

Results

All groups showed a strong linear relationship between stride length and cadence with no difference between groups (p>0.05). The intercept between cadence and stride length was lowest in the progressive supranuclear palsy group and highest for older adults (p<0.001). The progressive supranuclear palsy group had higher cadence than older adults (p>0.05), and greater step width and greater double support phase compared with the other two groups (p<0.05).

Conclusions

The temporal-spatial gait characteristics of progressive supranuclear palsy and Parkinson’s disease are largely similar, with similar disruption to scaling of stride length. The additional findings of increased step width and double support percentage suggest increased severity of gait abnormality compared to Parkinson’s disease, despite similar disease duration. The findings are consistent with the clinical features of greater instability and more rapid disease progression in progressive supranuclear palsy compared to Parkinson’s disease and implicates the early pathological involvement of brain regions involved in gait control.

In vivo evaluation of white matter pathology in patients of progressive supranuclear palsy using TBSS

INTRODUCTION

The purpose of this research is to study white matter (WM) changes in patients of progressive supranuclear palsy (PSP) using automated analysis of diffusion tensor imaging (DTI) indices.

METHODS

This was a prospective study comprising of 24 patients of PSP and 26 matched healthy controls. Fractional anisotropy, mean diffusivity (MD), axial diffusivity, and radial diffusivity (RD) changes were studied in the WM of the PSP patients using an automated analysis technique, tract-based spatial statistics (TBSS). Two subtypes of PSP, i.e., classic Richardson's syndrome (PSP-RS) and parkinsonian type (PSP-P), were also compared among themselves to identify relative severity of WM changes as well as identify spatial distribution of the differences. Clinicoradiological correlation was done to determine the strength of correlation between WM abnormalities identified using TBSS and clinical scores.

RESULTS

There were areas of significant abnormality seen in the frontoparietal cerebral WM, thalamus, midbrain tectum, superior cerebellar peduncle, and cerebellar WM. The abnormalities were more spatially widespread on MD and RD maps. Compared to PSP-P, the patients of PSP-RS had more spatial abnormalities localized to the frontal WM. There was no correlation between the observed WM changes and clinical rating scales.

CONCLUSIONS

The TBSS analysis showed widespread WM abnormalities in PSP patients including areas which have been shown to be involved in previous pathological studies. PSP-RS showed more severe white matter abnormality compared to the PSP-P subtype.

Progressive supranuclear palsy: new concepts

Progressive supranuclear palsy (PSP) is a distinctive form of neurodegenerative disease which affects the brainstem and basal ganglia. Patients present supranuclear ophthalmoplegia, postural instability and mild dementia. PSP is defined neuropathologically by the accumulation of neurofibrillary tangles in the subthalamic nucleus, pallidum, red nucleus, substantia nigra, striatum, pontine tegmentum, oculomotor nucleus, medulla and dentate nucleus. Over the last decade many lines of investigations have helped refine PSP in many aspects and it is the purpose of this review to help neurologists identify PSP, to better understand its pathophysiology and to provide a more focused, symptom-based treatment approach.

The role of dopaminergic imaging in patients with symptoms of dopaminergic system neurodegeneration

Diagnosis of neurological and psychiatric conditions associated with disturbances of dopaminergic functioning can be challenging, especially in the early stages, and may be assisted with biomarkers such as dopamine system imaging. Distinguishing between Alzheimer's disease and dementia with Lewy bodies is a major diagnostic challenge. Clinical diagnosis of Parkinson's disease is straightforward with classic presentation, but accurate distinction among Parkinsonian variants may be difficult; non-Parkinson's disease conditions are commonly misdiagnosed as Parkinson's disease, and ~20% of patients with Parkinson's disease are not clinically diagnosed despite coming to medical attention. Early and accurate diagnosis is desirable to improve management. Imaging of the dopamine transporter using single-photon emission computed tomography may be of particular utility in this regard. Abnormal imaging indicates underlying nigrostriatal neurodegeneration, supportive of a diagnosis of Parkinson's disease, atypical parkinsonism or dementia with Lewy bodies, and identifies patient groups in whom dopaminergic therapy may be beneficial. Normal imaging supports diagnosis of a condition not involving nigrostriatal neurodegeneration such as Alzheimer's disease, essential tremor or drug-induced parkinsonism and hence a different therapeutic approach. In patients in whom there was diagnostic uncertainty between degenerative parkinsonism and non-degenerative tremor disorders, baseline imaging with the dopamine transporter ligand [(123)I]ioflupane (DaTscan™) has shown 78% sensitivity and 97% specificity with reference to clinical diagnosis at 3 years, versus 93% and 46%, respectively, for baseline clinical diagnosis. In a Phase III trial of [(123)I]ioflupane in patients with initial clinical diagnosis of probable or possible dementia with Lewy bodies or non-Lewy body dementia, mean specificity for excluding non-Lewy body dementia (predominantly Alzheimer's disease) was 90.4%. Using clinical diagnosis as a reference against which to assess sensitivity and specificity of dopamine transporter imaging is a limitation, but definitive diagnosis via pathological confirmation is generally not feasible. In a series of patients with post-mortem brain examination, imaging using [(123)I]ioflupane has demonstrated higher sensitivity (88%) and specificity (100%) for differentiating dementia with Lewy bodies from non-Lewy body dementia than clinical diagnosis (75% and 42%, respectively). Dopaminergic system imaging may be particularly valuable in patients with clinically inconclusive parkinsonism or a clinical diagnosis of possible dementia with Lewy bodies; it is not helpful in differentiating between Parkinson's disease and atypical parkinsonism, although postsynaptic dopaminergic imaging may be of utility. Other potential uses of dopamine transporter imaging include identification of patients with premotor Parkinson's disease, monitoring disease progression in testing novel therapeutics, and as an inclusion criterion for entry into clinical trials.

Visual aspects of neurologic protein misfolding disorders

PURPOSE OF REVIEW

This article reviews topics of interest to the ophthalmologist relating to the most common neurologic protein misfolding disorders.

RECENT FINDINGS

Many neurodegenerative diseases are pathologically associated with misfolded proteins. These diseases cause a profound impact of disability to the individual and society. Alzheimer's disease costs alone are estimated to be over US$225 billion annually in the USA. The ophthalmologist is often asked to provide an opinion regarding the cause of visual symptoms in patients with these unique disorders.

SUMMARY

The categorization of neurodegenerative diseases has evolved based on advances in genetic, molecular and pathological research. In many neurodegenerative diseases, aggregation of a misfolded protein is responsible for the development of pathologic inclusions. When the misfolded protein is tau or synuclein, these diseases are called tauopathies or synucleinopathies, respectively. This article focuses on ophthalmic findings in some of the most common tauopathies and synucleinopathies: Alzheimer's disease, progressive supranuclear palsy, Parkinson's disease, dementia with Lewy bodies and multisystem atrophy.

[Progressive supranucleair palsy: acetylcholineeserase-inhibitor a possible therapy?]

Progressive supranucleair palsy (PSP) is a serious neurologic disease which is seldom diagnosed due to its complexity. In 1996 international diagnostic criteria were developed by a group of experts, the diagnosis remains complicated. We describe three cases, which were followed in the period 2001-2008. In these case reports we elaborate on the therapeutic use of rivastigmine. During off-label rivastigmine use, patients showed minimal further cognitive decline, specifically with respect to frontal defects. However, larger studies and trials are necessary to explore the effects of rivastigmine in patients with PSP.

Major depressive disorder preceding the onset of progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a neurodegenerative disease characterized by vertical supranuclear palsy and parkinsonian symptoms. The neuropsychiatric symptoms of PSP include anhedonia, depressed mood and cognitive impairment. Patients with PSP have an increased risk for developing depressive disorders within the next year. However, it is rare to find that major depressive disorder was the antecedent diagnosis of a patient who was later diagnosed with PSP. We present here a patient who suffered from PSP with repetitive falls, a masked face and dysarthria after developing a major depressive disorder.

Viral parkinsonism

Parkinson's disease is a debilitating neurological disorder that affects 1-2% of the adult population over 55 years of age. For the vast majority of cases, the etiology of this disorder is unknown, although it is generally accepted that there is a genetic susceptibility to any number of environmental agents. One such agent may be viruses. It has been shown that numerous viruses can enter the nervous system, i.e. they are neurotropic, and induce a number of encephalopathies. One of the secondary consequences of these encephalopathies can be parkinsonism, that is both transient as well as permanent. One of the most highlighted and controversial cases of viral parkinsonism is that which followed the 1918 influenza outbreak and the subsequent induction of von Economo's encephalopathy. In this review, we discuss the neurological sequelae of infection by influenza virus as well as that of other viruses known to induce parkinsonism including Coxsackie, Japanese encephalitis B, St. Louis, West Nile and HIV viruses.