Therapy for naming deficits in two variants of primary progressive aphasia

Background: Primary progressive aphasia (PPA) refers to a progressive and selective decline in language due to neurodegenerative disease. There are three variants of PPA, progressive nonfluent aphasia (PNFA), semantic dementia (SD), and logopaenic progressive aphasia (LPA). All variants include impaired object naming, but distinct underlying deficits might interfere with naming. Therefore, individuals with different types of PPA may respond differently to naming therapy.

Aims: To identify differences in patterns of success and generalisation in response to the same treatment in patient with LPA and a patient with SD. Furthermore, we wished to identify whether the treatment effect was item specific (trained words) or generalised to untrained words in trained or untrained categories.

Methods & Procedures: Participants included an individual with LPA and one with SD. An assessment of lexical processing was administered before and after a naming treatment to assess underlying deficits and generalisation effects. Therapy consisted of a cueing hierarchy treatment. Treatment items consisted of pictured objects in the categories of fruits/vegetables and clothing.

Outcomes & Results: Two different patterns of performance were observed. The LPA participant improved in naming of treated items and untreated items in both treated and untreated categories. The participant with SD improved in naming treated items only, but showed less deterioration in untreated items in treated than untreated categories.

Conclusions: Individuals with PPA can show improved naming (at least temporarily) with therapy, but generalisation to untrained items may depend on the underlying cause of the naming deficit, which may differ across subtypes.     

Relearning lost vocabulary in nonfluent progressive aphasia with MossTalk Words®

Background: The literature on aphasia has been growing rapidly, with reports of different therapeutic approaches for a post‐stroke anomia. While individuals with post‐stroke anomia frequently recover to some extent, the other end of the aphasia recovery continuum is occupied by those who experience relentless language dissolution as a result of progressive disorders such as primary progressive aphasia. One of the most recent additions to the field of aphasia rehabilitation is therapy whereby either part of or the entire therapy is administered via computer‐based programmes. There have been few treatment studies investigating the rehabilitation of language abilities in people with primary progressive aphasia (PPA).

Aims: The objectives of this investigation were to examine the ability of PPA individuals to relearn lost words and to determine the extent of benefits derived from MossTalk Words®, a computer‐based treatment for anomia.

Methods and Procedures: Using a multiple baseline across behaviours design, we explored treatment‐specific effects, maintenance, and generalisation of improvements derived from this therapy programme. Two participants with nonfluent PPA were treated, each on three lists of words for which low and stable baselines were first established. Sessions occurred two to three times a week. Treatment involved the presentation of a picture on the computer screen, with the participants being required to name it. Success in treatment was measured by probing list naming every second session. Once a participant attained 80% accuracy over two consecutive probes, or participated in 12 sessions (whichever occurred first), treatment of a list was terminated and the next list was started. Each participant was tested on all items immediately after therapy, and again 1 month later.

Outcomes and Results: Both participants improved their naming skills with the MossTalk Words®. P1 required only four sessions to reach the proposed criterion of 80% (up to 100%) correct on each list. The effects of treatment were maintained immediately and, to a lesser degree, 4 weeks later. P2 required all 12 sessions for each of the three lists. Results were variable immediately after testing, but seemingly maintained 4 weeks later.

Conclusions: The results demonstrate that both participants with primary progressive aphasia benefited (although to a different extent) from a computer‐based treatment for anomia. These results are encouraging and suggest that such a treatment may be a viable therapy approach for patients who suffer from PPA in the absence of a generalised cognitive impairment.     

“Do you have mowing the lawn?” – improvements in word retrieval and grammar following constraint-induced language therapy in primary progressive aphasia

Background: Much recent progress has been made in developing speech–language therapy in primary progressive aphasia (PPA). Several treatment approaches that have shown significant effects with people with aphasia have been adapted and re-evaluated for PPA. Constraint-induced aphasia therapy (CIAT) is a well-evaluated method that has yielded significant language improvements in people with post-stroke aphasia but has not yet been evaluated with people with PPA. Nevertheless, the combination of CIAT features like massed practice and a motivating communicative setting seem likely to make it a suitable tool for improving the speech and language performance of individuals with PPA as well.

Aims: This study investigates the effectiveness of a modified CIAT protocol on word retrieval, grammatical structure and connected speech in two individuals with non-fluent variant PPA (nfvPPA).

Methods and procedures: Two participants with nfvPPA took part in a 9-day intensive CIAT-based group therapy with additional computer-based home training. Stimuli were 120 photos of people performing daily life activities, which could be described using a simple (e.g., “The man is mowing the lawn”) or reduced (e.g., “mowing the lawn”) sentence structure. During the treatment phase, the participants were required to request picture cards from other group members using spoken language only. The task difficulty was increased hierarchically (shaped) in accordance to each participant’s performance level.

Outcomes and results: Directly after therapy, both participants achieved significant improvements in their noun and verb naming accuracy and their grammatical structure for trained items. Training effects were maintained 2 months after therapy. Moreover, generalisation to different pictures of the same item was found for both participants and one participant also showed improved grammatical structure when describing untrained pictures. No significant generalisation to untrained connected speech samples was observed for either participant.

Conclusion: This study illustrates that CIAT can be effective in people with PPA. However, further modifications of CIAT should be considered to facilitate generalisation and in order to determine which aspects of the treatment are most important.     

Telerehabilitation of anomia in primary progressive aphasia

Background: The efficacy of telerehabilitation-based treatment for anomia has been demonstrated in post-stroke aphasia, but the efficacy of this method of anomia treatment delivery has not been established within the context of degenerative illness.

Aims: The current study evaluated the feasibility and efficacy of a telerehabilitation-based approach to anomia treatment within the three subtypes of primary progressive aphasia (PPA).

Methods & Procedures: Each of the three telerehabilitation participants represented a distinct subtype of PPA. Following a baseline evaluation of language and cognition, a phonological treatment and an orthographic treatment were administered to all participants over the course of 6 months. One month after the end of treatment, a post-treatment evaluation began. All treatment sessions and the majority of the evaluation sessions were administered via telerehabilitation. Treatment effects were examined within each subject, and treatment effects were also compared between each telerehabilitation participant and a group of in-person participants who had the same subtype of PPA.

Outcomes & Results: All three telerehabilitation participants exhibited positive treatment effects. CGR (nonfluent/agrammatic variant PPA) and WCH (logopenic variant PPA) showed maintenance of naming for prophylaxis items under both treatment conditions, while ACR (semantic variant PPA) demonstrated increased naming of remediation items under the phonological treatment condition. Compared to in-person participants with the same subtype of PPA, each of the telerehabilitation participants typically showed effects that were either within the expected range or larger than expected.

Conclusions: Telerehabilitation-based anomia treatment is feasible and effective in all three subtypes of PPA.     

Motor speech disorders associated with primary progressive aphasia

Background: Primary progressive aphasia (PPA) and conditions that overlap with it can be accompanied by motor speech disorders. Recognition and understanding of motor speech disorders can contribute to a fuller clinical understanding of PPA and its management as well as its localisation and underlying pathology.

Aims: To review the types of motor speech disorders that may occur with PPA, its primary variants, and its overlap syndromes (progressive supranuclear palsy syndrome, corticobasal syndrome, motor neuron disease), as well as with primary progressive apraxia of speech.

Main Contribution: The review should assist clinicians’ and researchers’ understanding of the relationship between motor speech disorders and PPA and its major variants. It also highlights the importance of recognising neurodegenerative apraxia of speech as a condition that can occur with little or no evidence of aphasia.

Conclusion: Motor speech disorders can occur with PPA. Their recognition can contribute to clinical diagnosis and management of PPA and to understanding and predicting the localisation and pathology associated with PPA variants and conditions that can overlap with them.     

Taking words to a new level: a preliminary investigation of discourse intervention in primary progressive aphasia

Background: Despite a growing literature characterising connected speech and discourse impairments associated with primary progressive aphasia (PPA), intervention in PPA has focused predominantly on lexical retrieval and picture-naming treatments, with limited generalisation of therapy gains reported. Recent developments in the post-stroke aphasia literature with discourse-level approaches have provided highly promising findings for the generalisation of language gains to everyday communication, and an opportunity to investigate whether the same benefits may be found in the PPA population.

Aims: This study evaluated the effectiveness of a discourse intervention in two individuals with PPA to determine whether significant improvements were seen in word retrieval and discourse organisation in everyday discourse.

Methods & Procedures: KW, a 54-year-old man, who presented with semantic variant PPA, and AS, a 59-year-old woman, presenting with logopenic variant PPA, completed the NARNIA intervention programme (Whitworth, Leitão et al., 2015) in 20 sessions over a 10-week period. Discourse performance was sampled prior to intervention across 10 tasks involving four different genres, at one time point, and compared to performance immediately and four weeks post intervention. The multilevel intervention protocol aimed to increase awareness of word retrieval, sentence structure, and macrostructure of a range of discourse genre.

Outcomes & Results: Both participants made significant gains in discourse production immediately after intervention and when reassessed four weeks later, in the absence of change on naming tasks and in the context of stable overall cognitive performance. Significant gains were seen in the amount of overall output, noun and verb usage, and the number of body elements in macrostructure in everyday discourse in topics that were not trained in treatment. Further to the findings of the original NARNIA study in post-stroke aphasia, significant gains were also seen in narrative discourse across lexical categories for both participants. Informativeness and efficiency of communication also improved significantly for KW across all genres. Both participants reported significant gains in measures of social communication and participation.

Conclusions: The study suggests that improvements in everyday discourse may be possible when the discourse level is directly targeted, that lexical access can improve in the absence of targeting lexical items, and that discourse-level interventions have the potential to impact real-life communication in individuals with PPA. As the first known study to trial a multilevel intervention in the context of PPA, the findings may be of clinical and theoretical significance, and warrant further investigation.     

Prophylactic treatments for anomia in the logopenic variant of primary progressive aphasia: cross-language transfer

Background: Treatment studies for anomia in primary progressive aphasia (PPA) have rarely compared multiple treatments in the same individual, and few anomia treatment studies have included participants with the logopenic variant of PPA (lvPPA).

Aims: The goals of this study were to evaluate two types of treatment for anomia in a bilingual participant (ND) with lvPPA, and to examine possible cross-language transfer of treatment effects.

Methods & Procedures: ND is a Norwegian-English bilingual woman with lvPPA who began this study at the age of 69. In the phonological treatment, ND listened to a word while viewing a corresponding picture, and she repeated the word. In the orthographic treatment, ND read a word out loud while viewing the corresponding picture, and she then copied the word. Both treatments were conducted in English, and accuracy for three tasks (oral naming, written naming, and naming to definition) was assessed in English and Norwegian. The treatment occurred over a one-year period, with eight sessions at the laboratory during the first month, followed by monthly laboratory sessions and thrice-weekly home practice sessions during the subsequent 11 months. Post-treatment assessments were conducted at 1 week, 8 months, 1 year, 20 months, and 3 years.

Outcomes & Results: Compared to untrained items, the orthographic treatment resulted in greater English written naming accuracy. This treatment also resulted in cross-language transfer: greater Norwegian oral naming and naming to definition accuracy. The phonological treatment resulted in marginally greater English oral naming accuracy, but it did not have a significant effect on naming accuracy in Norwegian.

Conclusions: These findings suggest that the orthographic treatment was effective in strengthening the orthographic representations of the treated items, which facilitated ND’s written naming performance. The pattern of cross-language transfer suggests that the orthographic treatment also strengthened the language-independent semantic representations of the treated items, thereby facilitating access to their Norwegian phonological representations.     

A review of lexical retrieval intervention in primary progressive aphasia and Alzheimer’s disease: mechanisms of change,generalisation, and cognition

Background: While significant benefits of lexical retrieval intervention are evident within the primary progressive aphasia (PPA) and Alzheimer’s disease (AD) literature, an understanding of the mechanisms that underlie change is limited. Change mechanisms have been explored in the post-stroke aphasia literature and offer insight into how change occurs through interventions with progressive language disorders. Exploration of change mechanisms may progress our understanding as to how and why generalisation is likely, or not, to occur, as well as gain insight into the non-linguistic cognitive functions that may play a role.

Aims: This review of the literature aimed to (1) map the mechanisms of change that have been proposed or hypothesised within the PPA and AD lexical retrieval intervention literature to a theoretical framework based on a framework of motor recovery following stroke and accounts of change mechanisms within the post-stroke aphasia literature and explore whether particular mechanisms of change were associated with more effective outcomes; (2) determine whether particular mechanisms of change were associated with within- and across-level linguistic generalisation, and (3) investigate the role of non-linguistic cognitive functions in the lexical retrieval intervention studies reviewed here.

Main Contribution: A search of Medline, PsycINFO, and CINAHL identified 37 papers published between 1982 and April 2016 that reported lexical retrieval intervention in people with PPA or AD, categorised here according to whether the proposed change mechanism was stimulation (12 studies), relearning (21 studies), reorganisation (three studies), or cognitive-relay (two studies). Significant treatment gains, predominantly based on linguistic performance measures, were reported for both diagnostic groups in association with the proposed mechanisms of stimulation and relearning. Significant treatment gains were also reported for people with PPA in association with reorganisation and cognitive-relay mechanisms; these mechanisms were only employed in PPA studies. Varying outcomes for linguistic generalisation were reported in 26 PPA and six AD studies. Nineteen studies incorporated non-linguistic cognitive functions in intervention; these were limited to autobiographical memory (17 studies), episodic memory (three studies), or both (one study).

Conclusion: This review highlights that individuals with PPA and AD benefit from lexical retrieval intervention, irrespective of the mechanism of change, and that linguistic generalisation was reported in studies proposing different change mechanisms. Insufficient exploration of the role of non-linguistic cognitive functions was highlighted with respect to assessment, planning intervention, and interpreting intervention outcomes. Recommendations are made, with a view to heightening our ability to interpret intervention outcomes.     

Our journey with primary progressive aphasia

Background: My husband Boyd and I had a 6-year journey with primary progressive aphasia (PPA) that held many challenges for us along the way. This article describes that journey.

Aims & Main Contribution: I hope that hearing about our experience may be helpful to other people with a family member who has PPA, and provide clinicians and researchers insight into the PPA journey.

Conclusions: I hope that through more research, there can be more understanding about PPA and consequently more support for families with members suffering this cruel disease.     

Long-Term maintenance of anomia treatment effects in primary progressive aphasia

ABSTRACT

This study examined the maintenance of anomia treatment effects in primary progressive aphasia (PPA). Following baseline testing, a phonological treatment and an orthographic treatment were administered over the course of six months. The treatment stimuli consisted of nouns that were consistently named correctly at baseline (Prophylaxis items) and/or nouns that were consistently named incorrectly at baseline (Remediation items). Naming accuracy was measured at baseline, and it was measured at 1 month, 8 months, and 15 months post-treatment. The change in naming accuracy from baseline to each post-treatment evaluation was calculated within each treatment condition, and within a matched untrained condition. The change in naming accuracy was then compared between the three conditions. The results of these analyses indicate that phonological and orthographic treatments are both effective in the Prophylaxis and Remediation of anomia in all three variants of PPA. For Prophylaxis items, some of the effects of each treatment can persist for as long as 15 months post-treatment. These long-term treatment effects were more robust in the orthographic treatment condition and for participants with the semantic variant of PPA.     

Behavioural and neural changes after a “choice” therapy for naming deficits in aphasia: preliminary findings

Background: Anomia, difficulty producing words, is a pervasive symptom of many individuals with aphasia. We have developed a treatment for naming deficits—the Phonological Components Analysis (PCA) protocol—that has proven efficacious in improving word-finding abilities for individuals with post-stroke aphasia.

Aims: The aim of this investigation is to present preliminary findings exploring the potential influence of choice—that is the active engagement of a participant in therapy—on our PCA treatment.

Methods & Procedures: Five individuals with aphasia were treated in one of two conditions—Choice or No Choice. Potential changes in neural activation as a function of the treatment were also investigated. Two individuals (one from each condition) underwent functional MRI (fMRI) pre- and post-therapy.

Outcomes & Results: All the individuals demonstrated a significant treatment effect immediately post-treatment and at a 4-week follow-up and four of the five participants at an 8-week follow-up. Three also demonstrated generalisation to untrained items. Unfortunately, no clear-cut patterns emerged to allow us to make claims about the influence of choice, per se, on the behavioural manifestations of improved naming. Interestingly, the participant from the Choice condition showed neural activation changes post-treatment in frontal and parietal regions that were not evident for the participant in the No Choice condition. Moreover, these changes were accompanied by a larger treatment effect for that individual and generalisation to a novel naming task.

Conclusion: The efficacy of PCA treatment for naming deficits is further supported. In addition, the neuroimaging data suggest the possibility that active engagement of an individual in his/her therapy (in this case choosing phonological attributes of a target word) may exercise executive functions important for success in treating anomia. Also, continued exploration of task factors that may promote even better treatment effects using this protocol is warranted, as is continued investigation of the neural underpinnings associated with treatment effects.     

Longitudinal imaging and deterioration in word comprehension in primary progressive aphasia: Potential clinical significance

Background: Three variants of primary progressive aphasia (PPA), distinguished by language performance and supportive patterns of atrophy on imaging, have different clinical courses and the prognoses for specific functions. For example, semantic variant PPA alone is distinguished by impaired word comprehension. However, sometimes individuals with high education show normal performance on word-comprehension tests early on, making classification difficult. Furthermore, as the condition progresses, individuals with other variants develop word-comprehension deficits and other behavioural symptoms, making distinctions between variants less clear. Longitudinal brain imaging allows identification of specific areas of atrophy in individual patients, which identifies the location of disease in each patient.

Aims: We hypothesised that the areas of atrophy in individual PPA participants would be closely correlated with the decline in word comprehension over time. We propose that areas where tissue volume is correlated with word comprehension are areas that: (1) are essential for word comprehension, (2) compensate for word comprehension in some individuals with semantic variant PPA early in the course, and (3) show atrophy in individuals with logopenic and nonfluent variant PPA only late in the course.

Methods and Procedures: Fifteen participants with PPA (five logopenic variant PPA; eight semantic variant PPA; two nonfluent/agrammatic variant PPA; mean age 67.8), underwent high resolution magnetic resonance imaging and cognitive tests at least 9 months apart. The correlations between change in regional volumes and change in auditory word-comprehension scores were investigated using Spearman test.

Outcomes & Results: While scores on auditory word comprehension at Time 1 were correlated with volume loss in right and left temporal pole and left inferior temporal cortex (areas of atrophy associated with semantic variant PPA), deterioration in auditory word comprehension from Time 1 to Time 2 was associated with individual atrophy in left middle temporal cortex, left angular gyrus, and right inferior and middle temporal cortex.

Conclusions: Progressive atrophy in focal areas surrounding left temporal pole and left inferior temporal cortex, and right homologous area is closely related to progressive decline in auditory word comprehension. These correlations likely reflect areas that compensate for subtle deficits early in the course of semantic variant PPA, as well as areas that are critical for auditory word comprehension that eventually atrophy in individuals with other variants of PPA. Individual patterns of atrophy also help us understand and predict the clinical course of individuals, such as associated behavioural or motor deficits.     

Patterns of decline in naming and semantic knowledge in primary progressive aphasia

Background: Individuals with primary progressive aphasia (PPA) and their caregivers want to know what to expect so that they can plan support appropriately. The ability to predict decline in naming and semantic knowledge, and advise individuals with PPA and their caregivers regarding future planning, would be invaluable clinically.

Aims: The aims of this study were to investigate patterns of decline in naming and semantic knowledge in each of the clinical variants of PPA (logopenic variant PPA, lvPPA; nonfluent agrammatic PPA, nfaPPA; and semantic variant PPA, svPPA) and to examine the effects of other variables on rate of decline. We hypothesized that speech-language rehabilitation, higher education, and higher baseline test scores would be associated with slower decline, and older age with faster decline.

Methods and Procedures: A total of 94 participants with PPA underwent language testing, including 36 participants with lvPPA, 31 participants with nfaPPA, and 27 participants with svPPA. All participant groups were similar in age and education. We focused on decline on three tests: the short form of the Boston Naming Test (BNT), the Hopkins Assessment of Naming Actions (HANA), and the short form of the Pyramids and Palm Trees Test (PPTT).

Outcome and Results: Across language tests, the most precipitous rates of decline (loss of points per month) occurred in nfaPPA, followed by svPPA, then lvPPA. Female sex, longer symptom duration, higher baseline test score, and speech-language rehabilitation were associated with slower decline.

Conclusions: PPA variants were distinguishable by rapidity of decline, with nfaPPA having the most precipitous decline. As hypothesized, higher baseline test scores and speech-language rehabilitation were associated with slower decline. Surprisingly, age and education were not important prognostically for individuals in this study. Further study of prognostically-relevant variables in PPA is indicated in this population.     

Biomarkers in the primary progressive aphasias

Background: Primary progressive aphasia (PPA) is a progressive disorder of language that is increasingly recognised as an important presentation of a specific spectrum of neurodegenerative conditions.

Aims: In an era of etiologically specific treatments for neurodegenerative conditions, it is crucial to establish the histopathologic basis for PPA. In this review, I discuss biomarkers for identifying the pathology underlying PPA.

Main Contribution: Clinical syndromes suggest a probabilistic association between a specific PPA variant and an underlying pathology, but there are also many exceptions. A considerable body of work with biomarkers is now emerging as an important addition to clinical diagnosis. I review genetic, neuroimaging and biofluid studies that can help determine the pathologic basis for PPA.

Conclusions: Together with careful clinical examination, there is great promise that supplemental biomarker assessments will lead to accurate diagnosis of the pathology associated with PPA during life and serve as the basis for clinical trials in this spectrum of disease.     

Grammatical impairments in PPA

Background: Grammatical impairments are commonly observed in the agrammatic subtype of primary progressive aphasia (PPA-G), whereas grammatical processing is relatively preserved in logopenic (PPA-L) and semantic (PPA-S) subtypes.

Aims: We review research on grammatical deficits in PPA and associated neural mechanisms, with discussion focused on production and comprehension of four aspects of morphosyntactic structure: grammatical morphology, functional categories, verbs and verb argument structure, and complex syntactic structures. We also address assessment of grammatical deficits in PPA, with emphasis on behavioural tests of grammatical processing. Finally, we address research examining the effects of treatment for progressive grammatical impairments.

Main Contribution: PPA-G is associated with grammatical deficits that are evident across linguistic domains in both production and comprehension. PPA-G is associated with damage to regions including the left inferior frontal gyrus and dorsal white matter tracts, which have been linked to impaired comprehension and production of complex sentences. Detailing grammatical deficits in PPA is important for estimating the trajectory of language decline and associated neuropathology. We, therefore, highlight several new assessment tools for examining different aspects of morphosyntactic processing in PPA.

Conclusions: Individuals with PPA-G present with agrammatic deficit patterns distinct from those associated with PPA-L and PPA-S, but similar to those seen in agrammatism resulting from stroke, and patterns of cortical atrophy and white matter changes associated with PPA-G have been identified. Methods for clinical evaluation of agrammatism, focusing on comprehension and production of grammatical morphology, functional categories, verbs and verb argument structure, and complex syntactic structures are recommended and tools for this are emerging in the literature. Further research is needed to investigate the real-time processes underlying grammatical impairments in PPA, as well as the structural and functional neural correlates of grammatical impairments across linguistic domains. Few studies have examined the effects of treatment for grammatical impairments in PPA; research in this area is needed to better understand how (or if) grammatical processing ability can be improved, the potential for spared neural tissue to be recruited to support this and whether the neural connections within areas of dysfunctional tissue required for grammatical processing can be enhanced using cortical stimulation.     

Longitudinal study of single‐word comprehension in semantic dementia: A comparison with primary progressive aphasia and Alzheimer's disease

Background: Although semantic dementia (SD) is characterised by a multimodal loss of semantic knowledge, it has been demonstrated that lexical‐semantic representations are not equally disrupted in SD and that some categories may be recognised better than others. Little is known, however, about the pattern of the category‐specific comprehension deficits in SD and whether it differs from that of other forms of progressive aphasias.

Aims: This exploratory study aimed to investigate the evolution of category‐specific deficits of single‐word comprehension in progressive aphasias.

Methods & Procedures: A total of 19 patients with a clinical diagnosis of SD, 25 patients with primary progressive aphasia with agrammatic and relatively nonfluent speech (PPA), and 25 patients with Alzheimer's disease (AD) with aphasia were studied longitudinally with the Western Aphasia Battery (WAB). The Auditory Word Recognition subtest of the WAB was utilised to assess comprehension of words derived from different semantic categories.

Outcomes & Results: The analysis revealed that, over time, category‐specific deficits of single‐word comprehension were seen in all three groups of patients. Participants with SD as well as those with PPA and AD were impaired on both pointing to fingers and the right–left orientation task. However, patients with SD were the only group that showed defective recognition of their own body parts. Interestingly, individuals with SD had no difficulties identifying colours, letters, and numbers, even during the follow‐up testing. In addition, in all three groups the extent of category‐specific deficits was associated with the severity of aphasia.

Conclusions: These results indicate that category‐specific deficits of single‐word comprehension are frequently seen not only in patients with SD but also in individuals with PPA or AD, and that the extent of these deficits is associated with the severity of aphasia. However, the pattern of these deficits is often different in these three forms of neurodegenerative conditions and more dissociations between semantic categories are observed as each of these diseases progresses.     

Understanding and living with primary progressive aphasia: Current progress and challenges for the future

Background: Primary progressive aphasia (PPA) is a progressive language disorder in which aphasia is the first and most prominent symptom of degenerative brain disease. PPA has received increasing attention in the scientific literature over the past 30 years, but there remains a relative lack of awareness and understanding of it in the wider clinical community. As editors of the volume, Clinical Perspectives on Primary Progressive Aphasia, we invited the contributing authors to provide an up-to-date survey of research on a range of topics that are relevant to clinical practice in PPA.

Aims: The aim of this article is to address some key questions that may arise when an individual receives a diagnosis of PPA and to direct readers to additional sources of information in this volume and elsewhere that will allow them to gain further knowledge about topics of interest.

Main Contribution: We address the following questions: (1) What is PPA? (2) How is PPA diagnosed? (3) What happens to a person’s language when they have PPA? (4) How will the disease progress over time? (5) How does PPA impact a person’s life and the life of their family and friends? (6) What treatments and support are available? (7) What other services should we be providing?

Conclusions: Considerable progress has been made in our understanding of PPA and the relationship between the symptomatology, progression, pathology, and genetics of PPA. However, there are many challenges remaining, particularly in terms of ensuring that people with PPA and their families and friends receive optimal information and support at diagnosis and appropriate interventions and/or management strategies throughout their journey with PPA.     

Functional disability in primary progressive aphasia

Background: In primary progressive aphasia (PPA), assessment of language predominates over assessment of functional impairment in activities of daily living (ADLs) in clinical and research environments. Most of the knowledge on functional disability in PPA relies largely on anecdotal experience and limited numbers of studies published to date.

Aims: (1) To describe the different patterns of ADL functional disability in the main PPA variants: semantic variant, nonfluent aphasia, and the more recently defined logopenic variant; (2) to draw relations between functional disability, cognitive, and behavioural symptoms in the PPAs; (3) to examine the impact of functional disability on carer burden, and (4) to provide specific strategies to address the described problems.

Main Contribution: Profiles of disease progression are described from a functional perspective, as well as the relationship (or lack thereof) between functional disability and cognitive and behavioural symptoms. Dementia-management strategies for carers and professionals in overcoming day-to-day difficulties are provided, and the impact of functional deficits on those around the patient, including their spouses and children, are discussed.

Conclusions: Patterns of ADL functional disability and their progression vary between PPA subtypes. Understanding these different profiles of impairment is critical to the development of tailored interventions. There is a range of therapeutic strategies which can be trialled to promote improved ADL functioning, which in turn may also help in reducing levels of carer burden in PPA.     

Adherence to lexical retrieval treatment in Primary Progressive Aphasia and implications for candidacy

ABSTRACT

Background: Word-finding difficulties are a frequent, frustrating problem for people with Primary Progressive Aphasia (PPA), for which lexical retrieval treatment is a preferred behavioural intervention. The continuation of treatment over a long-term period is a proposed predictor of successful outcomes (i.e., maintenance of initial treatment gains). However, little is known about factors influencing adherence to lexical retrieval treatment in PPA.

Aims: The overarching aim of this study was to examine adherence in order to better inform candidacy for lexical retrieval treatment in PPA. We investigated the rate of adherence to lexical retrieval treatment and factors that contribute to continuing or discontinuing the treatment regime.

Methods & Procedures: We invited 30 caregivers of pwPPA who commenced lexical retrieval treatment at a specialist PPA clinic to complete a survey on their own and their partner with PPA’s experience of lexical retrieval treatment.

Outcomes & Results: 20 caregivers responded (66%). Reported rate of adherence to treatment was 60%. Adherence was more likely when the treatment commenced in the year of diagnosis. Caregivers of the pwPPA who continued treatment gave higher agreement ratings to statements indicating the importance of positive personal factors (patient motivation and mood) than statements about social support (presence of caregiver during therapy). Caregivers of pwPPA who ceased treatment within the first three months rated lack of motivation as more important than all other factors and as significantly more important than time constraints and physical illness.

Conclusions: This study provides indications of the characteristics of pwPPA who are likely to adhere to a lexical retrieval treatment regime and who are, therefore, preferred candidates for treatment. These results can inform clinical practice, guide participant recruitment for research, and assist in the development of clinical practice guidelines for speech pathology in PPA.     

A meta-analysis of word-finding treatments for aphasia

Background: The research literature on treatment methods for word-finding deficits in aphasia is extensive. A meta-analysis of studies for word-finding therapy was conducted in order to objectively synthesise this information to answer large-scale questions of treatment efficacy.

Aims: The purpose of this study was to examine the efficacy of various treatment approaches for word-finding deficits for individuals with aphasia. This analysis also examined gains made to trained and untrained words, the level of maintenance after therapy, and the effect of the time post-onset of aphasia on the recovery of language function.

Methods & Procedures: Various search methods were used to gather anomia treatment studies for this analysis. From 44 studies, 107 effect sizes were calculated for the final analysis. These data were sorted according to the following moderator variables: treatment category (semantic, phonological, or mixed), word set (trained, exposed-related, exposed-unrelated, unexposed-unrelated, and unexposed-related), follow-up measures, and median number of months post-onset.

Outcomes & Results: All therapy approaches showed evidence of efficacy, although the variance between studies was large. Strong gains were seen for trained and exposed words, but only minor gains for unexposed words. Large effects were seen for up to 2 months post-therapy, with lingering effects at 3 months post-therapy. Treatment appeared efficacious even for individuals that were years post-onset.

Conclusions: An objective synthesis of the literature shows that intervention for word-finding deficits is efficacious. However, the level of gains varied widely across studies and therapy approaches. As expected, little generalisation was found for untrained-unexposed words.