Characteristics and progression of cognitive deficits in progressive supranuclear palsy vs. multiple system atrophy and Parkinson's disease

Hearts and Minds: Emotion Recognition and Mentalizing in Parkinson's Disease and Progressive Supranuclear Palsy

OBJECTIVE

There are scarce data comparing Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP) in social cognition (SC). We aimed to compare patients with PSP and PD in SC.

METHODS

We included three groups: PD (n = 18), PSP (n = 20) and controls (n = 23). Participants underwent neuropsychological exams, including the mini-version of the Social and Emotional Assessment, which is composed of the facial emotion recognition test (FERT) and the modified faux-pas (mFP) test, which assesses Theory of Mind (ToM).

RESULTS

Patients with PD scored lower than controls in the FERT, but not in the mFP test. Patients with PSP performed worse than controls in both the mFP and FERT. PD and PSP groups did not differ in the FERT, but PSP performed worse than PD in the mFP test. The mFP test distinguished PSP from PD with 89% accuracy.

CONCLUSION

The assessment of ToM may contribute to the differentiation between PD and PSP.

Brain Dynamics Complexity as a Signature of Cognitive Decline in Parkinson's Disease

BACKGROUND

Higuchi's fractal dimension (FD) captures brain dynamics complexity and may be a promising method to analyze resting-state functional magnetic resonance imaging (fMRI) data and detect the neuronal interaction complexity underlying Parkinson's disease (PD) cognitive decline.

OBJECTIVES

The aim was to compare FD with a more established index of spontaneous neural activity, the fractional amplitude of low-frequency fluctuations (fALFF), and identify through machine learning (ML) models which method could best distinguish across PD-cognitive states, ranging from normal cognition (PD-NC), mild cognitive impairment (PD-MCI) to dementia (PDD). Finally, the aim was to explore correlations between fALFF and FD with clinical and cognitive PD features.

METHODS

Among 118 PD patients age-, sex-, and education matched with 35 healthy controls, 52 were classified with PD-NC, 46 with PD-MCI, and 20 with PDD based on an extensive cognitive and clinical evaluation. fALFF and FD metrics were computed on rs-fMRI data and used to train ML models.

RESULTS

FD outperformed fALFF metrics in differentiating between PD-cognitive states, reaching an overall accuracy of 78% (vs. 62%). PD showed increased neuronal dynamics complexity within the sensorimotor network, central executive network (CEN), and default mode network (DMN), paralleled by a reduction in spontaneous neuronal activity within the CEN and DMN, whose increased complexity was strongly linked to the presence of dementia. Further, we found that some DMN critical hubs correlated with worse cognitive performance and disease severity.

CONCLUSIONS

Our study indicates that PD-cognitive decline is characterized by an altered spontaneous neuronal activity and increased temporal complexity, involving the CEN and DMN, possibly reflecting an increased segregation of these networks. Therefore, we propose FD as a prognostic biomarker of PD-cognitive decline. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Subjective cognitive complaints in patients with progressive supranuclear palsy

Introduction

Subjective cognitive complaints (SCC) refer to self-reported cognitive decline that may or may not be reflected in objective neuropsychological evaluations. Such SCC are prevalent in neurodegenerative diseases, including Parkinson's disease (PD), but the prevalence and clinical features in patients with progressive supranuclear palsy (PSP) have not been investigated.

Methods

We recruited 83 PSP patients without dementia and investigated their SCC using a semi-structured interview. Comprehensive neuropsychological test results and patient clinical features were compared according to presence of SCC and underlying cognitive state.

Results

Among the 83 patients, 16 had normal cognition (NC), 67 had mild cognitive impairment (MCI), and 36 (43.4%) reported SCC. Among NC patients, 37.5% (6/16) had SCC, while 44.8% (30/67) of MCI patients reported SCC. There were no differences between the neuropsychological test results or demographic and clinical characteristics of PSP patients with or without SCC in the NC group. The demographic and clinical characteristics of the MCI+SCC (MCI with SCC)and MCI-SCC (MCI without SCC) groups were comparable, but the MCI+SCC group had significantly worse neuropsychological scores than the MCI-SCC group, particularly in tests assessing attention, language, visual memory, and fronto-executive function domains.

Discussion

While SCC are commonly reported by PSP patients, patients with PSP and MCI+SCC had worse cognitive function than those who did not report SCC. These findings suggest that SCC in PSP patients with MCI could be a worsening sign of cognitive function. Therefore, it is crucial for physicians to assess SCC in PSP patients and to provide timely diagnosis and management of cognitive decline.

Smaller and Denser Speech Graphs in Nondemented Patients with Progressive Supranuclear Palsy

The well-established semantic fluency test measures the ability to produce a sequence of spoken words from a particular category within a limited period of time. Like patients with Parkinson's disease (PD), patients with progressive supranuclear palsy (PSP) tend to produce fewer correct words than age-matched healthy adults. This study further examined the difference between patients with PSP and PD in their semantic fluency performance using a graph theory-based approach. Twenty-nine patients with PSP Richardson's syndrome (PSP-RS), thirty-eight patients with PD, and fifty-one healthy controls (HC) were recruited. All participants completed a standard semantic fluency test (animals). Their verbal responses were recorded, transcripted, and transformed into directed speech graphs. The speech graphs of the PSP-RS group showed higher density, shorter diameter, and shorter average shortest path than those of the PD and HC groups. It indicates that the PSP-RS group produced smaller and denser speech graphs than the PD and HC groups. In the PSP-RS group, moreover, the average shortest paths of the speech graphs correlated with the severity of motor symptoms. This study shows the potential of the graph theory-based approach in distinguishing the semantic fluency performance of nondemented patients with PSP-RS and PD.

Significance of clinical symptoms and red flags in early differential diagnosis of Parkinson's disease and atypical Parkinsonian syndromes

The clinical presentation of Parkinson's disease and atypical Parkinsonian syndromes is often heterogeneous. Additional diagnostic procedures including brain imaging and biomarker analyses can help to appreciate the various syndromes, but a precise clinical evaluation and differentiation is always necessary. To better assess the relevance of distinct clinical symptoms that arose within 1 year of disease manifestation and evaluate their indicative potential for an atypical Parkinsonian syndrome, we conducted a modified Delphi panel with seven movement disorder specialists. Five different topics with several clinical symptom items were discussed and consensus criteria were tested. This resulted in distinct symptom patterns for each atypical Parkinsonian syndrome showing the multitude of clinical involvement in each neurodegenerative disease. Strongly discriminating clinical signs were few and levels of indication were variable. A prospective validation of the assessments made is needed. This demonstrates that both clinical evaluation and elaborate additional diagnostic procedures are needed to achieve a high diagnostic standard.

Characteristics of Mild Cognitive Impairment and Associated Factors in MSA Patients

Mild cognitive impairment (MCI) in multiple-system atrophy (MSA) patients is common but remains poorly characterized, and the related factors are unclear. This retrospective study included 200 consecutive patients with a clinical diagnosis of possible or probable MSA, 102 MSA patients with MCI (MSA-MCI), and 98 MSA patients with normal cognition (MSA-NC). Cognitive profiles were compared between MSA-MCI and MSA-NC patients using the MoCA. In addition, demographic as well as major motor and nonmotor symptom differences were compared between MSA-MCI and MSA-NC patients. The median MMSE score was 26 points. Overall, MSA-MCI was observed in 51% of patients, with predominant impairment in visuospatial, executive, and attention functions compared with MSA-NC patients. MSA-MCI patients were older (p = 0.015) and had a later onset age (p = 0.024) and a higher frequency of hypertension, motor onset, and MSA with the predominant parkinsonism (MSA-P) phenotype than MSA-NC patients. The positive rate of orthostatic hypotension (OH) in MSA-MCI patients was significantly decreased and depression/anxiety was significantly increased compared with MSA-NC patients (p = 0.004). Multivariate logistic analysis showed that motor onset was independently associated with MCI in MSA patients. MSA-MCI patients had impairment in visuospatial, executive, and attention functions. More prominent memory impairment was observed in MSA-P than in MSA-C patients. Motor onset was independently associated with MCI in MSA patients. MCI was commonly presented in MSA with more prominent memory impairment in MSA-P. Future follow-up studies are warranted to identify more factors that influence cognitive impairment in MSA.

Pathomechanisms of cognitive impairment in progressive supranuclear palsy

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by early postural instability and falls, oculomotor dysfunction (vertical supranuclear gaze palsy), parkinsonism with poor response to levodopa, pseudobulbar palsy, and cognitive impairment. This four-repeat tauopathy is morphologically featured by accumulation of tau protein in neurons and glia causing neuronal loss and gliosis in the extrapyramidal system associated with cortical atrophy and white matter lesions. Cognitive impairment being frequent in PSP and more severe than in multiple system atrophy and Parkinson disease, is dominated by executive dysfunction, with milder difficulties in memory, and visuo-spatial and naming dysfunctions. Showing longitudinal decline, it has been related to a variety of pathogenic mechanisms associated with the underlying neurodegenerative process, such as involvement of cholinergic and muscarinergic dysfunctions, and striking tau pathology in frontal and temporal cortical regions associated with reduced synaptic density. Altered striatofrontal, fronto-cerebellar, parahippocampal, and multiple subcortical structures, as well as widespread white matter lesions causing extensive connectivity disruptions in cortico-subcortical and cortico-brainstem connections, support the concept that PSP is a brain network disruption disorder. The pathophysiology and pathogenesis of cognitive impairment in PSP, as in other degenerative movement disorders, are complex and deserve further elucidation as a basis for adequate treatment to improve the quality of life of patients with this fatal disease.

Structural and metabolic correlates of neuropsychological profiles in multiple system atrophy and Parkinson's disease

BACKGROUND

Despite increased recognition of cognitive impairment in Multiple System Atrophy (MSA), its neuroanatomical correlates are not well defined. We aimed to explore cognitive profiles in MSA with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) and their relationship to frontostriatal structural and metabolic changes.

METHODS

Detailed clinical and neuropsychological evaluation was performed together with diffusion tensor imaging (DTI) and [¹⁸F]-fluoro-deoxyglucose positron emission tomography ([¹⁸F]-FDG-PET) in patients with MSA-P (n = 11) and PD (n = 11). We compared clinical and neuropsychological data to healthy controls (n = 9) and correlated neuropsychological data with imaging findings in MSA-P and PD.

RESULTS

Patients with MSA-P showed deficits in executive function (Trail Making Test B-A) and scored higher in measures of depression and anxiety compared to those with PD and healthy controls. Widespread frontostriatal white matter tract reduction in fractional anisotropy was seen in MSA-P and PD compared to an imaging control group. Stroop Test interference performance correlated with [¹⁸F]-FDG uptake in the bilateral dorsolateral prefrontal cortex (DLPFC) and with white matter integrity between the striatum and left inferior frontal gyrus (IFG) in PD. Trail Making Test performance correlated with corticostriatal white matter integrity along tracts from the bilateral IFG in MSA-P and from the right DLPFC in both groups.

CONCLUSION

Executive dysfunction was more prominent in patients with MSA-P compared to PD. DLPFC metabolism and frontostriatal white matter integrity seem to be a driver of executive function in PD, whereas alterations in corticostriatal white matter integrity may contribute more to executive dysfunction in MSA-P.

Clinical, cognitive, and morphometric profiles of progressive supranuclear palsy phenotypes

The International Parkinson's and Movement Disorder Society (MDS) criteria for progressive supranuclear palsy (PSP) have broadened the clinical spectrum of the disease and established phenotypic characterization according to the predominant manifestation at onset. The objective of this study is to describe clinical/cognitive and imaging features of a monocentric cohort of PSP patients, highlighting different patterns of functional disability according to the assigned phenotype. We retrospectively reviewed clinical/imaging data of 53 PSP patients diagnosed with probable PSP according to the MDS criteria and 40 age/sex-matched healthy controls (HCs). Neurological/neuropsychological assessments were performed using standardized scales, as well as comprehensive magnetic resonance imaging (MRI) morphometric measurements. In our cohort, there were 24/53 PSP-RS (Richardson's syndrome), 13/53 PSP-P (Parkinsonism), 7/53 PSP-PGF (Progressive gait freezing), and 9/53 PSP-Cog (Cognitive impairment). PSP-Cog presented the worst motor profiles, the highest percentages of dementia and impaired functional autonomy; 4/9 PSP-Cog and 2/7 PSP-PGF died. PSP-P had the lowest motor/cognitive burden. All MRI parameters had good discriminative efficacy vs. HCs, with P/M 2.0 discriminating PSP-PGF from PSP-RS and PSP-Cog. We highlighted discrete clinical and imaging patterns that best characterize different PSP phenotypes. PSP-Cog and PSP-PGF/RS manifest greater incidence of dementia and motor disability, respectively, while PSP-P has a more benign course. The identification of different phenotypes may be the expression of different progression patterns requiring tailored approaches in terms of follow-up and treatment. These findings support the concept of discrete patterns of Tau pathology within the PSP spectrum and encourage research for phenotype-specific outcome measures.

Qualitative evaluation of the Rey-Osterrieth Complex Figure Test in patients with progressive supranuclear palsy

Objective: In early stages of disease, the differential diagnosis between Parkinson's Disease (PD) and atypical parkinsonism, such as Progressive Supranuclear Palsy (PSP), could be challenging. Growing attention has recently been dedicated to investigating neuropsychological markers of degenerative parkinsonism. The Rey-Osterrieth Complex Figure Test (ROCFT) copy score was hypothesized able to differentiate PSP from PD. However, ROCFT is a drawing test requiring multiple cognitive abilities and it is still unknown which of them assumes an important role in PSP performance. Using a qualitative scoring system, we investigated which cognitive abilities underpin the PSP performance at the ROCFT copy trial. Moreover, we evaluated usefulness of the BQSS scores in discriminating PSP from PD. Methods: Thirty PSP-Richardson's Syndrome (PSP-RS) patients, 30 PD patients, and 30 healthy control (HC) comparable for age, education, and gender were enrolled. All subjects underwent a neuropsychological evaluation; ROCFT copy were evaluated with the 36-Point Score and with the Boston Qualitative Scoring System (BQSS). Results: PSP-RS patients performed worse in ROCFT 36-Point Score and in several BQSS scores compared to other groups. Most suitable scores discriminating PSP-RS from PD were "Perseveration" and "Vertical Expansion" of BQSS. A logistic regression model considering "Perseveration" and "Vertical Expansion" showed a diagnostic accuracy of 83,3% for PSP-RS condition. Conclusion: our findings showed that "Perseveration" and "Vertical Expansion" BQSS scores were useful in discriminating PSP-RS from PD. "Perseveration" and "Vertical Expansion" BQSS scores might be included in the cognitive evaluation along with quantitative scores when PSP diagnosis is considered.

The Cognitive Profile of Atypical Parkinsonism: A Meta-Analysis

Atypical Parkinsonism (AP) syndromes are characterized by a wide spectrum of non-motor symptoms including prominent attentional and executive deficits. However, the cognitive profile of AP and its differences and similarities with that of Parkinson's Disease (PD) are still a matter of debate. The present meta-analysis aimed at identifying patterns of cognitive impairment in AP by comparing global cognitive functioning, memory, executive functions, visuospatial abilities, language, non-verbal reasoning, and processing speed test performances of patients with AP relative to healthy controls and patients with PD. All investigated cognitive domains showed a substantial impairment in patients with AP compared to healthy controls. When AP syndromes were considered separately, their cognitive functioning was distributed along a continuum from Multiple Systemic Atrophy at one extreme, with the least impaired cognitive profile (similar to that observed in PD) to Progressive Supranuclear Palsy, with the greatest decline in global cognitive and executive functioning (similar to Corticobasal Syndrome). These findings indicate that widespread cognitive impairment could represent an important clinical indicator to distinguish AP from other movement disorders.

Prospective CERAD Neuropsychological Assessment in Patients With Multiple System Atrophy

The objective of the study was to characterize the pattern of cognitive dysfunction in patients with multiple system atrophy (MSA) applying a standardized neuropsychological assessment. A total of 20 patients with the diagnosis of probable or possible MSA were enrolled for neuropsychological assessment applying the CERAD plus battery. All patients were tested at baseline and 14/20 patients received additional follow-up assessments (median follow-up of 24 months). Additionally, relationship between cortical thickness values/subcortical gray matter volumes and CERAD subitems was evaluated at baseline in a subgroup of 13/20 patients. Trail Making Test (TMT) was the most sensitive CERAD item at baseline with abnormal performance (z-score < −1.28) in one or both pathological TMT items (TMT-A, TMT-B) in 60% of patients with MSA. Additionally, there was a significant inverse correlation between the volume of the left and the right accumbens area and the TMT A item after adjusting for age (left side: p = 0.0009; right side p = 0.003). Comparing both subtypes, patients with MSA-C had significant lower values in phonemic verbal fluency (p = 0.04) and a trend for lower values in semantic verbal fluency (p = 0.06) compared to MSA-P. Additionally, patients with MSA-C showed significantly worse performance in the TMT-B task (p = 0.04) and a trend for worse performance in the TMT-A task (p = 0.06). Concerning longitudinal follow-up, a significant worsening in the TMT-B (p = 0.03) can be reported in MSA. In conclusion, frontal-executive dysfunction presents the hallmark of cognitive impairment in MSA.

Quantification of Brain β-Amyloid Load in Parkinson's Disease With Mild Cognitive Impairment: A PET/MRI Study

Background

Mild cognitive impairment in Parkinson's disease (PD-MCI) is associated with faster cognitive decline and conversion to dementia. There is uncertainty about the role of β-amyloid (Aβ) co-pathology and its contribution to the variability in PD-MCI profile and cognitive progression.

Objective

To study how presence of Aβ affects clinical and cognitive manifestations as well as regional brain volumes in PD-MCI.

Methods

Twenty-five PD-MCI patients underwent simultaneous PET/3T-MRI with [¹⁸F]flutemetamol and a clinical and neuropsychological examination allowing level II diagnosis. We tested pairwise differences in motor, clinical, and cognitive features with Mann–Whitney U test. We calculated [¹⁸F]flutemetamol (FMM) standardized uptake value ratios (SUVR) in striatal and cortical ROIs, and we performed a univariate linear regression analysis between the affected cognitive domains and the mean SUVR. Finally, we investigated differences in cortical and subcortical brain regional volumes with magnetic resonance imaging (MRI).

Results

There were 8 Aβ+ and 17 Aβ- PD-MCI. They did not differ for age, disease duration, clinical, motor, behavioral, and global cognition scores. PD-MCI-Aβ+ showed worse performance in the overall executive domain (p = 0.037). Subcortical ROIs analysis showed significant Aβ deposition in PD-MCI-Aβ+ patients in the right caudal and rostral middle frontal cortex, in precuneus, in left paracentral and pars triangularis (p < 0.0001), and bilaterally in the putamen (p = 0.038). Cortical regions with higher amyloid load correlated with worse executive performances (p < 0.05). Voxel-based morphometry (VBM) analyses showed no between groups differences.

Conclusions

Presence of cerebral Aβ worsens executive functions, but not motor and global cognitive abilities in PD-MCI, and it is not associated with middle-temporal cortex atrophy. These findings, together with the observation of significant proportion of PD-MCI-Aβ-, suggest that Aβ may not be the main pathogenetic determinant of cognitive deterioration in PD-MCI, but it would rather aggravate deficits in domains vulnerable to Parkinson primary pathology.

Parkinsonism and dementia

The aim of the present review is to summarize literature data on dementia in parkinsonian disorders. Cognitive decline and the gradual development of dementia are considered to be key features in the majority of parkinsonian conditions. The burden of dementia in everyday life of parkinsonian patients and their caregivers is vast and can be even more challenging to handle than the motor component of the disease. Common pathogenetic mechanisms involve the aggregation and spreading of abnormal proteins like alpha-synuclein, tau or amyloid in cortical and subcortical regions with subsequent dysregulation of multiple neurotransmitter systems. The degree of cognitive deterioration in these disorders is variable and ranges from mild cognitive impairment to severe cognitive dysfunction. There is also variation in the number and type of affected cognitive domains which can involve either a single domain like executive or visuospatial function or multiple ones. Novel genetic, biological fluid or imaging biomarkers appear promising in facilitating the diagnosis and staging of dementia in parkinsonian conditions. A significant part of current research in Parkinson's disease and other parkinsonian syndromes is targeted towards the cognitive aspects of these disorders. Stabilization or amelioration of cognitive outcomes represents a primary endpoint in many ongoing clinical trials for novel disease modifying treatments in this field. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

Impact of social and mobility restrictions in Parkinson's disease during COVID-19 lockdown

BACKGROUND

The consequences of strict COVID-19 mobility restrictions on motor/non-motor features in Parkinson's disease (PD) have not been systematically studied but worse mobility and quality of life have been reported. To elucidate this question, 12 mild to moderate PD patients were assessed in March 2020 before and after two months of isolation as part of a clinical study that had to be interrupted due to the pandemic and the implementation of COVID19 mobility restrictions.

METHODS

Twelve patients were systematically evaluated before and after the lockdown period as part of a larger cohort that previously underwent thermal water rehabilitation. Clinical outcomes were the Body Mass index, the Mini-Balance Evaluation Systems Test, the MDS-Unified Parkinson's Disease Rating Scale part III, the 6 Minute Walking Test and the New Freezing of Gait Questionnaire. Global cognition was evaluated with the Montreal Cognitive Assessment scale. The impact of COVID-19 restrictions on quality of life and functional independence was evaluated with The Parkinson's disease Quality of life (PDQ-39), the Activities of Daily Living (ADL) and Instrumental Activities of Daily Living questionnaires (IADL) and the Parkinson's disease cognitive functional rating scales (PD-CFRS).

RESULTS

After two months of isolation the Mini-BESTest score worsened (p=0.005), and four patients reported one or more falls during the lockdown. BMI increased (p=0.031) while the remaining clinical variables including quality of life did not change.

CONCLUSION

We observed moderate worsening at Mini-BESTest, greater risk of falls and increased body weight as consequence of prolonged immobility. We believe negative effects were partially softened since patients were in contact with our multidisciplinary team during the lockdown and had previously received training to respond to the needs of this emergency isolation. These findings highligh the importnace of patient-centered interventions in PD management.

Validation of the Parkinson's Disease Caregiver Burden Questionnaire in Progressive Supranuclear Palsy

Progressive supranuclear palsy (PSP) is an atypical Parkinson syndrome with axial akinetic-rigid symptoms, early postural instability, and ocular motor impairments. Patients experience a rapid loss of autonomy and care dependency; thus, caregivers must assist in the activities of daily living early in the course of the disease. Caregiver burden is an extremely important factor in disease management. However, there are no specific questionnaires for assessment of caregiver burden in PSP. This study aims to validate the Parkinson's disease caregiver burden questionnaire (PDCB) as a specific measure of caregiver burden in PSP. PSP patients were assessed by the PSP rating scale, PSP quality-of-life questionnaire (PSP-QoL), Montreal cognitive assessment test (MoCA), and geriatric depression scale (GDS-15). Caregivers filled out the short form 36-health survey, GDS-15, PDCB, and the caregiver burden inventory (CBI). 22 patient caregiver pairs completed the study. PDCB showed a highly significant correlation with the CBI (r 0.911; p < 0.001). Internal reliability of the PDCB measured by Cronbach's alpha was favourable at 0.803. These data support the specificity of the PDCB in PSP caregivers. Future studies with larger sample sizes of PSP patients and caregivers and a multicentric longitudinal design should be performed to gain further insight of caregiver burden in PSP.

Cognitive and behavioral profile of progressive supranuclear palsy and its phenotypes

BACKGROUND

Although several progressive supranuclear palsy (PSP) phenotypes have recently been described, studies identifying cognitive and neuropsychiatric differences between them are lacking.

METHODS

An extensive battery of cognitive and behavioural assessments was administered to 63 PSP patients, 25 PD patients with similar sociodemographic characteristics, and 25 healthy controls. We analysed differences in phenomenology, frequency and severity of cognitive and neuropsychiatric symptoms between PSP, PD and HC, and between PSP subtypes.

RESULTS

Regarding phenotypes, 64.6% met criteria for Richardson's syndrome (PSP-RS), 10.7% PSP with predominant Parkinsonism (PSP-P), 10.7% with PSP progressive gait freezing (PSP-PGF), and 10.7% PSP with predominant speech/language disorder (PSP-SL). Impairment was more severe in the PSP group than in the PD and HC groups regarding motor scores, cognitive testing and neuropsychiatric scales. Cognitive testing did not clearly differentiate between PSP phenotypes, but PSP-RS and PSP-SL appeared to have more cognitive impairment than PSP-PGF and PSP-P, mainly due to an increased impairment in frontal executive domains. Regarding neuropsychiatric disturbances, no specific behavior was more common in any of the PSP subtypes.

CONCLUSION

Motor deficits delineate the phenotypes included in currently accepted MDS-PSP criteria. Cognition and behavioural disturbances are common in PSP and allow us to distinguish this disorder from other neurological diseases, but they do not differentiate between PSP phenotypes.

Neuropsychological assessment could distinguish among different clinical phenotypes of progressive supranuclear palsy: A Machine Learning approach

Progressive supranuclear palsy (PSP) is a rare, rapidly progressive neurodegenerative disease. Richardson's syndrome (PSP-RS) and predominant parkinsonism (PSP-P) are characterized by wide range of cognitive and behavioural disturbances, but these variants show similar cognitive pattern of alterations, leading difficult differential diagnosis. For this reason, we explored with an Artificial Intelligence approach, whether cognitive impairment could differentiate the phenotypes. Forty Parkinson's disease (PD) patients, 25 PSP-P, 40 PSP-RS, and 34 controls were enrolled following the consensus criteria diagnosis. Participants were evaluated with neuropsychological battery for cognitive domains. Random Forest models were used for exploring the discriminant power of the cognitive tests in distinguishing among the four groups. The classifiers for distinguishing diseases from controls reached high accuracies (86% for PD, 95% for PSP-P, 99% for PSP-RS). Regarding the differential diagnosis, PD was discriminated from PSP-P with 91% (important variables: HAMA, MMSE, JLO, RAVLT_I, BDI-II) and from PSP-RS with 92% (important variables: COWAT, JLO, FAB). PSP-P was distinguished from PSP-RS with 84% (important variables: JLO, WCFST, RAVLT_I, Digit span_F). This study revealed that PSP-P, PSP-RS and PD had peculiar cognitive deficits compared with healthy subjects, from which they were discriminated with optimal accuracies. Moreover, high accuracies were reached also in differential diagnosis. Most importantly, Machine Learning resulted to be useful to the clinical neuropsychologist in choosing the most appropriate neuropsychological tests for the cognitive evaluation of PSP patients.

Patient and care partner views on exercise and structured physical activity for people with Progressive Supranuclear Palsy

INTRODUCTION

Progressive Supranuclear Palsy (PSP) is a debilitating form of atypical Parkinsonism. People living with PSP experience movement disorders affecting walking, balance and eye movements. The role of exercise in optimising movement remains unclear.

AIMS

To identify beliefs about exercise and structured physical activity through the experience of people with PSP.

METHODS

Using a phenomenological theoretical framework, qualitative methods were employed to obtain the views of people living with PSP, and their care partners, by in-depth interviews. Questions derived from a systematic review and expert opinions guided the interviews which were audio-recorded, transcribed and de-identified. Two researchers independently conducted thematic analysis and reached consensus on emerging themes.

RESULTS

There were 16 participants. Four themes were identified: (i) there are beliefs and preferences about exercise and physical activity that can impact on engagement; (ii) difficulty coping with disease progression impacts activities; (iii) facilitators to exercise include individual preferences, access to facilities and expert advice; and (iv) perceived barriers include beliefs about limited exercise options, falls risk, cost, transport and access to credible information.

DISCUSSION

People living with PSP want early guidance about the condition and the role of exercise. It is important to quickly enable people to have access to evidence and resources supporting exercise and structured physical activities. Consideration of individual preferences and access to expert advice facilitate engagement. Individual barriers need to be identified and solutions found.

CONCLUSION

People living with PSP are amenable to exercise, especially early in the disease process. Clear guidelines are warranted to document which exercises, and physical activities are most beneficial.

Dissociable effects of subthalamic nucleus deep brain stimulation surgery and acute stimulation on verbal fluency in Parkinson's disease

OBJECT

Verbal fluency (VF) is the cognitive test which shows the most consistent and persistent post-operative decline after subthalamic deep brain stimulation (STN-DBS) in Parkinson's disease (PD). However, the reasons are not completely understood, and the debate has focused on two hypotheses: a surgical effect or an acute STN-DBS effect.

METHODS

We recruited 3 PD samples: (1) a group assessed before and after STN-DBS surgery (2) a group assessed On vs. Off STN-DBS and (3) an unoperated PD control group. All groups performed letter, category and switching category VF tasks. The total number of correct words generated were noted and measures of clustering and switching were also obtained.

RESULTS

We found a significant effect of STN-DBS surgery on all VF tasks which was associated with a post-operative decline in the total number of words generated, and a reduction of phonemic switching during the letter and category VF tasks, and a reduction of semantic clustering for category VF. By contrast to the effects of surgery, acute On vs. Off stimulation did not influence the number of words generated on any of the VF tasks. Acute stimulation only produced two effects on the category VF task: increased semantic cluster size and decreased number of semantic switches when STN-DBS was switched On.

CONCLUSIONS

This study differentiates between the effects of STN-DBS surgery and acute stimulation on VF performance. Our findings indicate that the STN-DBS effect on VF are a surgical and not an acute STN stimulation effect.

Effects of gender on cognitive and behavioral manifestations in multiple system atrophy

Gender differences have been described in several neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. The effects of gender on cognitive and behavioral manifestations in multiple system atrophy and the changes of cognitive functions over time according to gender have not been investigated so far. Fifty-five patients with a diagnosis of multiple system atrophy underwent a comprehensive neuropsychological and neuropsychiatric battery at baseline and 26 of them could be re-evaluated at 1-year follow-up. At baseline women with multiple system atrophy had poorer global cognitive state and visuo-spatial abilities, and a higher prevalence of depression and apathy than males. At follow-up, female patients deteriorated more than males on attention abilities and motor functions, and had a higher prevalence of depression than men. Executive functions and visuo-spatial abilities significantly worsened over time in both groups. Mild Cognitive Impairment single domain was significantly more frequent in females than males. Cognitive and behavioral differences between genders in multiple system atrophy involve global cognition, planning, attention, visual-perceptive skills, and depression, with female patients more compromised than males. Female patients deteriorated more than men over time as for motor functions and attention. Further longitudinal studies are deserved to confirm gender differences in progression of cognitive and behavioral features of multiple system atrophy.