The Relationship between Behavioural Changes, Cognitive Symptoms, and Functional Disability in Primary Progressive Aphasia: A Longitudinal Study

Association of Regional Cortical Network Atrophy With Progression to Dementia in Patients With Primary Progressive Aphasia

BACKGROUND AND OBJECTIVES

Patients with primary progressive aphasia (PPA) have gradually progressive language deficits during the initial phase of the illness. As the underlying neurodegenerative disease progresses, patients with PPA start losing independent functioning due to the development of nonlanguage cognitive or behavioral symptoms. The timeline of this progression from the mild cognitive impairment stage to the dementia stage of PPA is variable across patients. In this study, in a sample of patients with PPA, we measured the magnitude of cortical atrophy within functional networks believed to subserve diverse cognitive and affective functions. The objective of the study was to evaluate the utility of this measure as a predictor of time to subsequent progression to dementia in PPA.

METHODS

Patients with PPA with largely independent daily function were recruited through the Massachusetts General Hospital Frontotemporal Disorders Unit. All patients underwent an MRI scan at baseline. Cortical atrophy was then estimated relative to a group of amyloid-negative cognitively normal control participants. For each patient, we measured the time between the baseline visit and the subsequent visit at which dementia progression was documented or last observation. Simple and multivariable Cox regression models were used to examine the relationship between cortical atrophy and the likelihood of progression to dementia.

RESULTS

Forty-nine patients with PPA (mean age = 66.39 ± 8.36 years, 59.2% females) and 25 controls (mean age = 67.43 ± 4.84 years, 48% females) were included in the data analysis. Greater baseline atrophy in not only the left language network (hazard ratio = 1.47, 95% CI = 1.17-1.84) but also in the frontoparietal control (1.75, 1.25-2.44), salience (1.63, 1.25-2.13), default mode (1.55, 1.19-2.01), and ventral frontotemporal (1.41, 1.16-1.71) networks was associated with a higher risk of progression to dementia. A multivariable model identified contributions of the left frontoparietal control (1.94, 1.09-3.48) and ventral frontotemporal (1.61, 1.09-2.39) networks in predicting dementia progression, with no additional variance explained by the language network (0.75, 0.43-1.31).

DISCUSSION

These results suggest that baseline atrophy in cortical networks subserving nonlanguage cognitive and affective functions is an important predictor of progression to dementia in PPA. This measure should be included in precision medicine models of prognosis in PPA.

The cognitive and behavioral correlates of functional status in patients with frontotemporal dementia: A pilot study

Objective: Frontotemporal dementia (FTD) impinges significantly on cognition, behavior, and everyday functioning. Goal of the present study is the detailed description of behavioral disturbances and functional limitations, as well as the investigation of associations between cognition, behavior, and functional impairment among FTD patients. Given the importance of maintaining a satisfying functional status as long as possible, this study also aims to identify the cognitive correlates of compensatory strategy use in this clinical group. Methods: A total of 13 patients diagnosed with FTD (behavioral variant FTD = 9, non-fluent variant primary progressive aphasia = 3, semantic dementia = 1) were administrated a broad range of neuropsychological tests for the assessment of different cognitive abilities. Behavioral symptomatology and performance on everyday activities were rated with informant-based measures. Descriptive statistics were used for the delineation of behavioral and functional patterns, whereas stepwise multiple regression analyses were performed to identify associations between cognition, behavior, and functional status. Results: Negative symptoms, especially apathy, were found to predominate in the behavior of FTD patients. Instrumental tasks, such as housework and leisure activities, appeared to be the most impaired functional domains. Working memory was the strongest cognitive correlate of performance across various domains of everyday functioning, whereas working memory along with short-term verbal memory accounted for a great proportion of variance in compensatory strategy use. Behavioral disturbances and especially negative symptoms were also found to contribute significantly to functional impairment in FTD. Conclusions: Executive dysfunction, as well as behavioral disturbances contribute significantly to functional disability in FTD. Early interventions tailored at these domains may have the potential to improve functional outcomes and delay the rate of functional decline among FTD patients.

Utility of a Spanish version of Three Words-Three Shapes Test to detect memory impairment in primary progressive aphasia

INTRODUCTION

Three Words-Three Shapes (3W3S) is a bedside test that assesses verbal and non-verbal memory and has proven useful in staging memory decline in amnestic disorders and primary progressive aphasia. Given its simple structure, the 3W3S can be easily adapted to other languages maintaining the original shapes and only modifying the words. We aim to validate a Spanish version of the 3W3S test and establish whether memory loss patterns present in amnesic disorders associated with Alzheimer's etiology and PPA were correctly characterized.

METHOD

The translation and adaptation of the 3W3S were performed according to standardized guidelines and applied to a cohort of patients with Dementia of Alzheimer's type (DAT = 20), mild cognitive impairment (aMCI= 20), primary progressive aphasia (PPA = 20), and healthy controls (HC = 20).

RESULTS

In verbal memory performance, PPA patients' score was lower than that of MCI and HC and similar to DAT's in the effortless encoding (p < 0.001), delayed recall (p < 0.001), and recognition (p < 0.012). For non-verbal performance, PPA patients performed better than DAT and similar to HC and MCI subjects (p < 0.001).

CONCLUSIONS

Results show good applicability of 3W3S to determine memory function in PPA patients, independently from language ability. Visual and verbal components of memory are dissociated in PPA.

Enhanced positive emotional reactivity in frontotemporal dementia reflects left-lateralized atrophy in the temporal and frontal lobes

In frontotemporal dementia (FTD), left-lateralized atrophy patterns have been associated with elevations in certain positive emotions. Here, we investigated whether positive emotional reactivity was enhanced in semantic variant primary progressive aphasia (svPPA), an FTD syndrome that targets the left anterior temporal lobe. Sixty-one participants (16 people with svPPA, 24 people with behavioral variant FTD, and 21 healthy controls) viewed six 90-sec trials that were comprised of a series of photographs; each trial was designed to elicit a specific positive emotion, negative emotion, or no emotion. Participants rated their positive emotional experience after each trial, and their smiling behavior was coded with the Facial Action Coding System. Results indicated that positive emotional experience and smiling were elevated in svPPA in response to numerous affective and non-affective stimuli. Voxel-based morphometry analyses revealed that greater positive emotional experience and greater smiling in the patients were both associated with smaller gray matter volume in the left superior temporal gyrus (pFWE < .05), among other left-lateralized frontotemporal regions. Whereas enhanced positive emotional experience related to atrophy in middle superior temporal gyrus and structures that promote cognitive control and emotion regulation, heightened smiling related to atrophy in posterior superior temporal gyrus and structures that support motor control. Our results suggest positive emotional reactivity is elevated in svPPA and offer new evidence that atrophy in left-lateralized emotion-relevant systems relates to enhanced positive emotions in FTD.

Functional Disabilities and Psychiatric Symptoms in Primary Progressive Aphasia

OBJECTIVE

The aims of this study are to describe the chronology of functional disabilities in primary progressive aphasia (PPA), and to examine associations between psychiatric comorbidities and functional disabilities.

METHODS

We conducted a retrospective data analysis using subjects enrolled at Alzheimer's Disease Research Centers between 2005 and 2019. Data were obtained from the National Alzheimer's Coordinating Center database. We included subjects whose primary diagnosis was PPA. Functional status was coded as a binary variable for the following functions: ambulation, transaction skills, verbal communication, meal preparation, and self-care. Behavioral data derived from the Neuropsychiatric Inventory Questionnaire. Descriptive statistics and cox proportional hazard analyses were used to characterize the emergence of disabilities and their association with psychiatric comorbidities.

RESULTS

Data included 91 subjects with a clinical dementia rating scale of zero at baseline. At the initial visit, no individuals had impairments in self-care, while 7% had impairments in transactions, 3% in ambulation, and 2% in meal preparation. Ninety-three percent had language impairments at the onset of the study, and all by visit 4. By visit 5, 41% of patients had impairments in ambulation and in self-care, 49% were impaired in meal preparation and 70% had impairment in transactions. The presence of anxiety, depression, sleep disturbance and psychosis were all significantly associated with an increased risk for multiple functional disabilities.

CONCLUSION

These findings provide clinicians with guidance for forecasting disabilities and targeting interventions in PPA.

Longitudinal Changes in Cognition, Behaviours, and Functional Abilities in the Three Main Variants of Primary Progressive Aphasia: A Literature Review

Primary progressive aphasias (PPAs) are a group of neurodegenerative diseases presenting with insidious and relentless language impairment. Three main PPA variants have been described: the non-fluent/agrammatic variant (nfvPPA), the semantic variant (svPPA), and the logopenic variant (lvPPA). At the time of diagnosis, patients and their families' main question pertains to prognosis and evolution, but very few data exist to support clinicians' claims. The objective of this study was to review the current literature on the longitudinal changes in cognition, behaviours, and functional abilities in the three main PPA variants. A comprehensive review was undertaken via a search on PUBMED and EMBASE. Two authors independently reviewed a total of 65 full-text records for eligibility. A total of 14 group studies and one meta-analysis were included. Among these, eight studies included all three PPA variants. Eight studies were prospective, and the follow-up duration was between one and five years. Overall, svPPA patients showed more behavioural disturbances both at baseline and over the course of the disease. Patients with lvPPA showed a worse cognitive decline, especially in episodic memory, and faster progression to dementia. Finally, patients with nfvPPA showed the most significant losses in language production and functional abilities. Data regarding the prodromal and last stages of PPA are still missing and studies with a longer follow-up observation period are needed.

Verbal Short-Term Memory Disturbance in the Primary Progressive Aphasias: Challenges and Distinctions in a Clinical Setting

Impaired verbal ‘phonological’ short-term memory is considered a cardinal feature of the logopenic variant of primary progressive aphasia (lv-PPA) and is assumed to underpin most of the language deficits in this syndrome. Clinically, examination of verbal short-term memory in individuals presenting with PPA is common practice and serves two objectives: (i) to help understand the possible mechanisms underlying the patient’s language profile and (ii) to help differentiate lv-PPA from other PPA variants or from other dementia syndromes. Distinction between lv-PPA and the non-fluent variant of PPA (nfv-PPA), however, can be especially challenging due to overlapping language profiles and comparable psychometric performances on verbal short-term memory tests. Here, we present case vignettes of the three PPA variants (lv-PPA, nfv-PPA, and the semantic variant (sv-PPA)) and typical Alzheimer’s disease (AD). These vignettes provide a detailed description of the short-term and working memory profiles typically found in these patients and highlight how speech output and language comprehension deficits across the PPA variants differentially interfere with verbal memory performance. We demonstrate that a combination of verbal short-term and working memory measures provides crucial information regarding the cognitive mechanisms underlying language disturbances in PPA. In addition, we propose that analogous visuospatial span tasks are essential for the assessment of PPA as they measure memory capacity without language contamination.

The natural history of primary progressive aphasia: beyond aphasia

INTRODUCTION

Primary progressive aphasia (PPA) is divided into three prototypical subtypes that are all characterized by their single core symptom of aphasia. Although later in their course, other cognitive, behavioral, and motor domains may become involved, little is known about the progression profile of each subtype relative to the other subtypes.

METHODS

In this longitudinal retrospective cohort study, based on the recent biomarker-supported diagnostic criteria, 24 subjects diagnosed with semantic variant (svPPA), 22 with non-fluent variant (nfvPPA), and 18 with logopenic variant (lvPPA) were collected and followed up for 1-6 years. Symptom distribution, cognitive test and neuropsychiatric inventory scores, and progression into another syndrome were assessed.

RESULTS

Over time, lvPPA progressed with broader language problems (PPA-extended) and nfvPPA progressed to mutism, whereas semantic impairment remained the major problem in svPPA. Apart from linguistic problems, svPPA developed pronounced behavioral disturbances, whereas lvPPA exhibited a greater cognitive decline. By contrast, in nfvPPA motor deficits were more common. Furthermore, within 5 years (IQR = 2.5) after clinical onset, 65.6% of the patients additionally fulfilled the clinical criteria for another neurodegenerative syndrome (PPA-plus). Fourteen out of 24 (58%) svPPA patients additionally met the diagnostic criteria of behavioral variant frontotemporal dementia (5.1 years, IQR = 1.1), whereas the clinical features of 15/18 (83%) lvPPA patients were consistent with Alzheimer disease dementia (4.5 years IQR = 3.4). Furthermore, 12/22 (54%) of the subjects with the nfvPPA progressed to meet the diagnostic criteria of corticobasal syndrome, progressive supranuclear palsy, or motor neuron disease (5.1 years IQR = 3.4).

DISCUSSION

Despite aphasia being the initial and unique hallmark of the syndrome, our longitudinal results showed that PPA is not a language limited disorder and progression differs widely for each subtype, both with respect to the nature of symptoms and disease duration.

Functional decline in the aphasic variant of Alzheimer's disease

INTRODUCTION

Primary progressive aphasia (PPA) is a clinical dementia syndrome associated with frontotemporal lobar degeneration (FTLD) or Alzheimer's disease (AD). Impairment in activities of daily living is essential for dementia diagnosis, yet less is known about the neuropathologic impact on functional decline in PPA, especially over time.

METHODS

Activities of Daily Living Questionnaire (ADLQ) ratings were compared by suspected underlying pathology between 17 PPA^Aβ+ and 11 PPA^Aβ- participants at 6-month intervals for 2 years using a linear mixed-effects model. A general linear model examined associations between functional decline and cortical thickness at baseline.

RESULTS

Groups did not differ in demographics or aphasia severity at baseline, yet overall and subdomain scores of the ADLQ were significantly worse for PPA^Aβ+ compared to PPA^Aβ- (P = .015) at each interval across 18 months.

DISCUSSION

Functional decline appears more pronounced and disrupts more aspects of life activities for individuals with non-semantic PPA with suspected AD versus non-AD neuropathology.

Beyond language impairment: Profiles of apathy in primary progressive aphasia

Primary progressive aphasia (PPA) is characterised by predominant language and communication impairment. However, behavioural changes, such as apathy, are increasingly recognised. Apathy is defined as a reduction in motivation and goal-directed behaviour. Recent theoretical models have suggested that apathy can be delineated into multiple dimensions: executive apathy (i.e., deficits in maintaining goals and organisation), emotional apathy (i.e., emotional blunting and indifference) and initiation apathy (i.e., reduced self-initiation). Whether the nature of apathy differs between clinical variants of PPA, and across early and late disease stages, remains to be established. Here, carers/informants of 20 semantic variant PPA (svPPA), 15 non-fluent variant PPA (nfvPPA), 16 logopenic variant PPA (lvPPA) and 25 healthy older controls completed the Dimensional Apathy Scale to quantify executive, emotional and initiation apathy. Voxel-based morphometry was used to identify associations between dimensions of apathy and regions of grey matter intensity decrease. Our behavioural results showed greater executive and initiation apathy in late svPPA than in late nfvPPA patients, while late svPPA had greater emotional apathy than both late nfvPPA and late lvPPA groups. Executive and initiation apathy were significantly higher than premorbid levels in all PPA subtypes, while elevated emotional apathy was only seen in early and late svPPA. Distinct neural correlates were identified across apathy dimensions. Executive apathy correlated with grey matter intensity of the left dorsolateral prefrontal and inferior parietal cortices; emotional apathy with the left medial prefrontal, insular and cerebellar regions; and initiation apathy with right parietal areas. Our findings are the first to reveal evidence of the dimensional nature of apathy in PPA, with different clinical signatures observed for each subtype. From a clinical standpoint, these results will inform the development of targeted interventions for specific aspects of apathy which emerge in PPA.

Longitudinal cognitive and functional changes in primary progressive aphasia

OBJECTIVE

The variants of primary progressive aphasia (PPA) are predominantly diagnosed on the basis of specific profiles of language impairments. Deficits in other cognitive domains and their evolution over time are less well documented. This study examined the cognitive profiles of the PPA variants over time and determined the contribution of cognition on functional capacity.

METHODS

Longitudinal performance on the Addenbrooke's Cognitive Examination-III (ACE-III) total and cognitive subdomains were investigated in 147 PPA individuals (41 logopenic [lv-PPA], 44 non-fluent [nfv-PPA], and 62 semantic variants [sv-PPA]). The relative contribution of ACE-III subdomain scores to overall functional capacity over time was identified using mixed and hierarchical regression modelling.

RESULTS

The annual rate of global ACE-III decline was twice that in lv-PPA than in nfv-PPA and sv-PPA, despite lv-PPA performing intermediate to the other variants at baseline assessment. Notably, attention and visuospatial subdomains declined faster in lv-PPA than in nfv-PPA and sv-PPA; and memory impairment was more severe in lv-PPA than in nfv-PPA at all time points. Functional decline was comparable across PPA variants; however, the contribution of cognition on functional capacity varied across variants and over time.

CONCLUSION

The cognitive profiles of the PPA variants are distinct at baseline and over time. Crucially, cognitive decline in lv-PPA was more widespread and pervasive than in nfv-PPA and sv-PPA. Our findings also demonstrate the complex interplay between cognition and functional capacity. This study underscores the importance of routinely assessing cognition and functional capacity in PPA to improve diagnostic accuracy and provide targeted support services.

Distinguishing Frontotemporal Dementia From Alzheimer Disease Through Everyday Function Profiles: Trajectories of Change

BACKGROUND

Different dementia syndromes display different patterns of everyday functioning. This article explored different patterns of functioning at baseline and trajectories of change in behavioral variant frontotemporal dementia (bvFTD) and Alzheimer disease (AD).

METHODS

Data from the Uniform Data Set of the National Alzheimer's Coordinating Centre were employed. The Functional Assessment Questionnaire assessed functioning at up to 7 follow-up visits. Independent t tests assessed variations in functioning between syndromes at baseline. Linear mixed-effect modeling explored longitudinal functional trajectories between syndromes.

RESULTS

Data from 3351 patients (306 bvFTD and 3,045AD) were analyzed. At baseline, patients with bvFTD performed all daily activities poorer than AD dementia. Linear mixed models showed a significant effect of syndrome and time on functioning, and evidence of interaction between syndrome and time, with bvFTD showing a steeper decline for using the stove and travel.

CONCLUSIONS

Findings can help in the effective care planning of everyday functioning for bvFTD and AD dementia.

Primary Progressive Aphasia: Natural History in an Italian Cohort

BACKGROUND/AIMS

Few longitudinal studies have explored the progression of cognitive and functional impairment of patients with primary progressive aphasia (PPA). The aims of the study were to describe the clinical, neuroimaging, and genetic features of a cohort of 68 PPA patients, and to outline the natural history of the disease.

MATERIALS AND METHODS

A sample of 23 patients with the logopenic variant, 26 with the nonfluent/agrammatic variant, and 19 with the semantic variant was retrospectively collected and followed-up for a maximum of 6 years. Clinical-neuropsychological assessment, fluorodeoxyglucose positron emission tomographic imaging, and genetic analyses were acquired at baseline. Disease progression was evaluated in terms of language impairment, global cognitive decline, and functional dependency.

RESULTS

During follow-up, one third of subjects presented total language loss, and 20% severe functional dependency. Global cognitive decline after the first year (hazard ratio, 5.93; confidence interval, 1.63-21.56) and high schooling (hazard ratio, 0.07; confidence interval, 0.008-0.74) represented risk factors for functional impairment. The apolipoprotein E status was associated with the progression of cognitive decline. Positive family history for dementia was frequent and 3 genetic autosomal dominant mutations were identified.

CONCLUSIONS

There were no differences in the progression of PPA subtypes. Genetics plays an important role in disease onset and progression.

Baseline MRI associates with later naming status in primary progressive aphasia

Advanced imaging studies in neurodegenerative disease have yielded new insights into subtypes of disease, progression of disease in various brain regions, and changes in structural and functional connectivity between brain regions related to symptom progression. However, few studies have revealed imaging markers at baseline that correlate with rate or degree of decline in function. Here we tested the hypothesis that imaging features at baseline correlate with outcome of naming in primary progressive aphasia. We obtained longitudinal multimodal imaging in 15 individuals with primary progressive aphasia at the same time points as assessment of naming. We found that functional connectivity between particular brain regions (measured with resting state functional connectivity magnetic resonance imaging) is strongly associated with accuracy of naming 21 months later, independently of baseline severity of naming impairment. These data indicate that functional connectivity may carry information about later performance in naming, and is potentially useful for refining prognosis.

The tailored activity program (TAP) to address behavioral disturbances in frontotemporal dementia: a feasibility and pilot study

PURPOSE

To explore the feasibility of implementing the Tailored Activity Program with a cohort of people with frontotemporal dementia and their carers (dyads).

METHODS

The Tailored Activity Program is an occupational therapy based intervention that involves working collaboratively with family carers and prescribes personalized activities for behavioral management in people with dementia. Twenty dyads randomized into the study (Tailored Activity Program: n = 9; Control: n = 11) were assessed at baseline and 4-months. Qualitative analyzes evaluated feasibility and acceptability of the program for the frontotemporal dementia cohort, and quantitative analyzes (linear mixed model analyzes, Spearman's rho correlations) measured the impact of the program on the dyads.

RESULTS

The Tailored Activity Program was an acceptable intervention for the frontotemporal dementia dyads. Qualitative analyses identified five themes: "carer perceived benefits", "carer readiness to change", "strategies used by carer to engage person with dementia", "barriers to the Tailored Activity Program uptake/implementation", and "person with dementia engagement". Quantitative outcomes showed an overall reduction of behavioral symptoms (F_18.34 = 8.073, p = 0.011) and maintenance of functional performance in the person with dementia (F_18.03 = 0.375, p = 0.548).

CONCLUSIONS

This study demonstrates the potential for using an activity-based intervention such as the Tailored Activity Program in frontotemporal dementia. Service providers should recognize that while people with frontotemporal dementia present with challenging issues, tailored therapies may support their function and reduce their behavioral symptoms. Implications for rehabilitation The Tailored Activity Program is an occupational therapy based intervention that involves prescribing personalized activities for behavioral management in dementia. The Tailored Activity Program is an acceptable and feasible intervention approach to address some of the unique behavioral and functional impairments inherent in frontotemporal dementia.

Executive Dysfunction and Behavioral Symptoms Are Associated with Deficits in Instrumental Activities of Daily Living in Frontotemporal Dementia

BACKGROUND

Deficits in instrumental activities of daily living (ADLs) may be more prominent in behavioral variant frontotemporal dementia (bvFTD) than in nonfluent/agrammatic variant primary progressive aphasia (nfvPPA) or semantic variant primary progressive aphasia (svPPA). It is uncertain whether frontotemporal dementia (FTD) subgroups exhibit different patterns and/or predictors of functional impairment.

METHODS

We examined data from participants diagnosed with bvFTD (n = 607), svPPA (n = 132), and nfvPPA (n = 155) who were included in the National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) and assessed with the Functional Activities Questionnaire (FAQ). Stepwise multiple linear regression analyses were performed to identify associations between FAQ scores and cognitive/behavioral deficits using the NACC UDS neuropsychological testing battery and the Neuropsychiatric Inventory Questionnaire.

RESULTS

FAQ scores were higher in bvFTD than svPPA or nfvPPA. Functional deficits across FTD subtypes differed in severity, but not pattern, and were driven by executive dysfunction and behavioral symptoms.

CONCLUSION

Executive dysfunction and behavioral symptoms underlie instrumental ADL deficits in FTD, which are most prominent in bvFTD.