Bringing words back to mind – Improving word production in semantic dementia

(What) can patients with semantic dementia learn?

Semantic Dementia (SD) is a neurodegenerative disease characterised by progressive deterioration of semantic knowledge, resulting in diminished understanding of concepts, whether encountered in verbal or non-verbal form. Over the past three decades, a number of studies employing a range of treatment techniques and learning methods have examined whether patients with SD can relearn previously known concepts or learn and retain new information. In this article, we review this research, addressing two main questions: a) Can aspects of semantic knowledge that are 'lost' due to degeneration be re-acquired? b) How much do other memory systems (working and episodic memory) interact with and depend on semantic memory? Several studies demonstrate successful relearning of previously known words and concepts in SD, particularly after regular, prolonged practice; but this success tends to diminish once practice ceases, and furthermore often fails to generalise to other instances of the same object/concept. This pattern suggests that, with impaired semantic knowledge, learning relies to an abnormal extent on perceptual factors, making it difficult to abstract away from the specific visual or other perceptual format in which a given concept has been trained. Furthermore, the impact of semantic 'status' of a word or object on both working and episodic memory indicates pervasive interaction of these other memory systems with conceptual knowledge.

Smartphone use as an efficient tool to improve anomia in primary progressive aphasia

Cognitive interventions are helpful in the non-pharmacological management of Primary progressive aphasia (PPA) and other neurodegenerative disorders of cognition, by helping patients to compensate for their cognitive deficits and improve their functional independence. In this study, we examined the effectiveness of cognitive rehabilitation based on the use of mobile device technology in PPA. The aim of this research study was to determine if BL, a patient with semantic variant PPA (svPPA) and severe anomia, was able to learn using specific smartphone functions and an application to reduce her word finding difficulties. She was trained during the intervention sessions on a list of target pictures to measure changes in picture naming performance. Errorless learning was applied during learning. BL quickly learned to use smartphone functions and the application over the course of the intervention. She significantly improved her anomia for trained pictures, and to a lesser extent for untrained semantically related pictures. Picture naming performance was maintained six months after the intervention, and she continued to use her smartphone regularly to communicate with family members and friends. This study confirms that smartphone use can be learned in PPA, which can help reduce the symptoms of anomia and improve communication skills.

Computer-Based Naming Treatment for Semantic Variant Primary Progressive Aphasia With History of Traumatic Brain Injury: A Single-Case Experimental Design

PURPOSE

The purpose of this study was to investigate the effectiveness of a self-administered naming treatment for one individual, B.N., presenting with semantic variant primary progressive aphasia (svPPA) and a history of traumatic brain injury (TBI).

METHOD

Naming treatment included components of Lexical Retrieval Cascade Treatment and was self-administered using an adaptive spaced retrieval software, Anki. Using a multiple-baseline, single-case experimental design, naming accuracy probes were taken during pretreatment, treatment, posttreatment, and follow-up (through 12 months) for 60 trained words and 10 untrained words. Item-level Bayesian generalized mixed-effects models were used to estimate (a) the treatment effect for trained words, (b) change in untrained words, and (c) maintenance of treatment effects from posttreatment to each subsequent follow-up.

RESULTS

Statistical analyses revealed that a gain of 35 out of 60 trained words (35.3; 90% CI [30.6, 39.5]) was directly attributable to treatment. Following treatment, evidence of generalization to untrained words was not observed. During the follow-up period, there was gradual decline in naming accuracy of trained items.

CONCLUSIONS

The positive treatment results reported here support the use of self-administered naming treatments for those with svPPA and a history of TBI. Although the utility of this treatment approach is constrained by patient factors including motivation, self-administered naming treatments represent a unique opportunity to expand access to speech-language intervention for people with svPPA, including those with concomitant diagnoses.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25119080.

Phase I trial of the MuSic to CONnect (MuSiCON) protocol: feasibility and effect of choir participation for individuals with cognitive impairment

BACKGROUND

Individuals living in residential aged care facilities with cognitive decline are at risk of social isolation and decreased wellbeing. These risks may be exacerbated by decline in communication skills. There is growing awareness that group singing may improve sense of wellbeing for individuals with dementia. However, to date few studies have examined broader rehabilitative effects on skills such as communication of individuals with dementia.

AIMS

To determine the feasibility and acceptability of the MuSic to Connect (MuSiCON) choir and language/communication assessment protocol in people with cognitive impairment living in non-high-care wards of a residential facility.

METHODS

Six individuals with mild-moderate cognitive impairment participated (age range 55-91 years, five female, one male). A mixed method approach was used. Quantitative outcomes included attendance rates, quality of life and communication measures. The qualitative measure was a brief survey of experience completed by participants and carers post-intervention.

RESULTS

Overall, MuSiCON was perceived as positive and beneficial, with high attendance, perception of improved daily functioning and high therapeutic benefit without harmful effects. While there was no reliable change in communication skills over the course of the six-week intervention, most participants successfully engaged in the conversational task, suggesting it is a suitable and ecologically valid method for data collection.

CONCLUSIONS

The MuSiCON protocol demonstrated feasibility and was well received by participants and staff at the residential facility. A co-design approach is recommended to improve upon feasibility, acceptability and validity of the assessment protocol prior to Phase II testing.

Behavioral Treatment for Speech and Language in Primary Progressive Aphasia and Primary Progressive Apraxia of Speech: A Systematic Review

Primary progressive aphasia (PPA) and primary progressive apraxia of speech (PPAOS) are neurodegenerative syndromes characterized by progressive decline in language or speech. There is a growing number of studies investigating speech-language interventions for PPA/PPAOS. An updated systematic evaluation of the treatment evidence is warranted to inform best clinical practice and guide future treatment research. We systematically reviewed the evidence for behavioral treatment for speech and language in this population. Reviewed articles were published in peer-reviewed journals through 31 May 2021. We evaluated level of evidence, reporting quality, and risk of bias using a modified version of the American Speech-Language Hearing Association (ASHA) Levels of Evidence, an appraisal point system, additional reporting quality and internal/external validity items, and, as appropriate, the Single Case Experimental Design Scale or the Physiotherapy Evidence Database - PsycBITE Rating Scale for Randomized and Non-Randomized Controlled Trials. Results were synthesized using quantitative summaries and narrative review. A total of 103 studies reported treatment outcomes for 626 individuals with PPA; no studies used the diagnostic label PPAOS. Most studies evaluated interventions for word retrieval. The highest-quality evidence was provided by 45 experimental and quasi-experimental studies (16 controlled group studies, 29 single-subject designs). All (k = 45/45) reported improvement on a primary outcome measure; most reported generalization (k = 34/43), maintenance (k = 34/39), or social validity (k = 17/19) of treatment for at least one participant. The available evidence supports speech-language intervention for persons with PPA; however, treatment for PPAOS awaits systematic investigation. Implications and limitations of the evidence and the review are discussed.

Baseline structural imaging correlates of treatment outcomes in semantic variant primary progressive aphasia

Semantic variant primary progressive aphasia (svPPA) is a neurodegenerative disorder characterized by a loss of semantic knowledge in the context of anterior temporal lobe atrophy (left > right). Core features of svPPA include anomia and single-word comprehension impairment. Despite growing evidence supporting treatment for anomia in svPPA, there is a paucity of research investigating neural mechanisms supporting treatment-induced gains and generalization to untrained items. In the current study, we examined the relation between the structural integrity of brain parenchyma (tissue inclusive of gray and white matter) at pre-treatment and treatment outcomes for trained and untrained items in a group of 19 individuals with svPPA who completed lexical retrieval treatment. Two structural neuroimaging approaches were used: an exploratory, whole-brain, voxel-wise approach and an a priori region of interest (ROI) approach. Based on previous research, bilateral temporal (inferior, middle, and superior temporal gyri), parietal (supramarginal and angular gyri), frontal (inferior and middle frontal gyri) and medial temporal (hippocampus and parahippocampal gyri) ROIs were selected from the Automated Anatomical Labeling (AAL) atlas. Analyses revealed improved naming of trained items and generalization to untrained items following treatment, providing converging evidence that individuals with svPPA can benefit from treatment for anomia. Better post-treatment naming accuracy was associated with the structural integrity of inferior parietal cortex and the hippocampus. Specifically, improved naming of trained items was related to the left supramarginal (phonological processing) and angular gyri (phonological and semantic processing), and improved naming of trained and untrained items was related to the left hippocampus (episodic, context-based memory). Future research should examine treatment outcomes in relation to pre-treatment functional and structural connectivity as well as changes in network dynamics following speech-language intervention to further elucidate the neural mechanisms underlying treatment response in svPPA and related disorders.

Executive functions in primary progressive aphasia: A meta-analysis

Executive functions (EFs) refer to a set of cognitive processes, specifically shifting, inhibition, updating of working memory, and are involved in the cognitive control of behavior. Conflicting results have been reported regarding impairments of EFs in Primary Progressive Aphasia (PPA). We performed a multi-level meta-analysis to confirm whether deficits of EFs exist in this population, focusing on a common EFs composite, and the components shifting, inhibition and updating separately. We included 141 studies that report on 294 EFs tasks. The overall mean weighted effect size was large (d = -1,28), indicating poorer EFs in PPA as compared to age-matched cognitively healthy controls. Differences between effect sizes of the EFs components were not significant, indicating all components are affected similarly. Overall, moderator analysis revealed that PPA variant and disease duration were significant moderators of performance, while task modality and years of education were not. The non-fluent/agrammatic PPA and the logopenic PPA variants were similarly affected, but the semantic variant was affected to a lesser extent. We discuss implications for clinical and research settings, and future research.

Maintenance and Generalization of Lexical Items in Primary Progressive Aphasia: Reflections From the Roundtable Discussion at the 2021 Clinical Aphasiology Conference

PURPOSE

Our capacity to engage in society and maintain meaningful relationships is dependent on intact communication skills. They are compromised in a neurodegenerative language disorder termed primary progressive aphasia (PPA). Behavioral interventions for PPA are sparse and often limited to impairment-based approaches or communication skills training, although various functional interventions have been also described. The slow but relentless language decline does not naturally support maintenance and/or generalization of treatment gains, which should be the ultimate goal of any therapy. However, in some cases and under certain conditions, maintenance and generalization may be accomplished. While each type of intervention has much to offer to the PPA population, the clinical and research realms can benefit from a collective professional discussion on aspects of intervention conducive to maintenance and/or generalization of treatment gains in PPA. Such a discussion took place at the 2021 Clinical Aphasiology Conference during two roundtable sessions. The aims of the sessions were to review the premises of successful treatment approaches in PPA and to discuss factors fostering or inhibiting maintenance and generalization in PPA.

CONCLUSIONS

Current literature delivers, albeit in small doses, encouraging evidence for clinicians providing language intervention to patients with PPA. Although PPA is a progressive disorder, both the immediate treatment effects and, in many cases, evidence of maintenance and generalization demonstrate that improvements may be long lasting and transferrable. Several factors may enhance maintenance and generalization effects, including repeated practice, working with multiple exemplars of treatment items, booster sessions, group programs with built-in individual sessions, spared semantics, and personal relevance, to name a few. With this evidence in hand, we need to become more diligent about measuring and reporting clinical outcomes and delivering interventions that support maintenance and generalization of therapeutic gains beyond the clinician's office.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19836370.

Anomia is present pre-symptomatically in frontotemporal dementia due to MAPT mutations

INTRODUCTION

A third of frontotemporal dementia (FTD) is caused by an autosomal-dominant genetic mutation in one of three genes: microtubule-associated protein tau (MAPT), chromosome 9 open reading frame 72 (C9orf72) and progranulin (GRN). Prior studies of prodromal FTD have identified impaired executive function and social cognition early in the disease but few have studied naming in detail.

METHODS

We investigated performance on the Boston Naming Test (BNT) in the GENetic Frontotemporal dementia Initiative cohort of 499 mutation carriers and 248 mutation-negative controls divided across three genetic groups: C9orf72, MAPT and GRN. Mutation carriers were further divided into 3 groups according to their global CDR plus NACC FTLD score: 0 (asymptomatic), 0.5 (prodromal) and 1 + (fully symptomatic). Groups were compared using a bootstrapped linear regression model, adjusting for age, sex, language and education. Finally, we identified neural correlates of anomia within carriers of each genetic group using a voxel-based morphometry analysis.

RESULTS

All symptomatic groups performed worse on the BNT than controls with the MAPT symptomatic group scoring the worst. Furthermore, MAPT asymptomatic and prodromal groups performed significantly worse than controls. Correlates of anomia in MAPT mutation carriers included bilateral anterior temporal lobe regions and the anterior insula. Similar bilateral anterior temporal lobe involvement was seen in C9orf72 mutation carriers as well as more widespread left frontal atrophy. In GRN mutation carriers, neural correlates were limited to the left hemisphere, and involved frontal, temporal, insula and striatal regions.

CONCLUSION

This study suggests the development of early anomia in MAPT mutation carriers, likely to be associated with impaired semantic knowledge. Clinical trials focused on the prodromal period within individuals with MAPT mutations should use language tasks, such as the BNT for patient stratification and as outcome measures.

Training flexible conceptual retrieval in post-stroke aphasia

Semantic therapy in post-stroke aphasia typically focusses on strengthening links between conceptual representations and their lexical-articulatory forms to aid word retrieval. However, research has shown that semantic deficits in this group can affect both verbal and non-verbal tasks, particularly in patients with deregulated retrieval as opposed to degraded knowledge. This study, therefore, aimed to facilitate semantic cognition in a sample of such patients with post-stroke semantic aphasia (SA) by training the identification of both strong and weak semantic associations and providing explicit pictorial feedback that demonstrated both common and more unusual ways of linking concepts together. We assessed the effects of this training on (i) trained and untrained items; and (ii) trained and untrained tasks in eleven individuals with SA. In the training task, the SA group showed improvement with practice, particularly for trained items. A similar untrained task using pictorial stimuli (Camel and Cactus Test) also improved. Together, these results suggest that semantic training can be beneficial in patients with SA and may show some degree of generalization to untrained situations. Future research should seek to understand which patients are most likely to benefit from this type of training.

Association of Long-Term Speech Therapy and Neuromodulation in Primary Progressive Aphasia: Lessons from a Case Report

Primary progressive aphasia (PPA) is a neurodegenerative disorder with a progressive loss of language. Long-term support requires speech therapy but also individually set training programs. Here we propose an 8-month individualized speech-training program which alternates 3-week periods of transcranial direct current stimulation (tDCS) treatment with intensive daily language exercises and a 3-week period without tDCS treatment and a less intensive language exercise from home in a patient with non-fluent variant PPA (nfvPPA). The endpoints were the following: adherence to this program, language data after 8 months, questionnaires related to emotional valence, and brain volume changes. The results showed a persistent adherence after 8 months and a positive compliance reported by both the patient and the partner. The language evaluation showed a clinical stabilization. Moreover, a significant and positive influence of tDCS on mood was observed. This is, to our knowledge, the first ever published report of a combined neuromodulation and language training during the course of 8 months. Our finding suggests the feasibility of programs integrating hospital speech therapy, home training, and tDCS modulation in PPA. Further studies should be conducted in order to disentangle the contextual influences on language performance from the tDCS intervention effects and to address the observation of an initial improvement and a subsequent stabilization effect of language performances.

Behavioral interventions for primary progressive aphasia

Primary progressive aphasia (PPA) is a neurodegenerative syndrome characterized by a gradual loss of communication ability. Due to the centrality of communication deficits, speech-language pathologists play a prominent role in the provision of care for individuals with PPA. In this chapter, we outline a person-centered approach to the management of PPA that aims to preserve independence for as long as possible while anticipating future decline in communication and other domains. A growing evidence base supports the utility of speech-language treatment approaches in PPA, including restitutive, compensatory, and communication partner-focused techniques. Restitutive interventions aim to rebuild lost communication skills, such as naming or fluent speech production. Compensatory approaches include training with high- and low-tech augmentative and alternative communication systems that provide complementary means of communication beyond speech. Communication partner interventions focus on education and strategy training in order to equip conversation partners as skilled communication facilitators. Throughout intervention, clinicians should aim to provide treatment that impacts functional communication and promotes social engagement. Given the documented benefits of speech-language intervention in PPA, we are optimistic that such treatment will become the standard of care and that additional research will continue to improve the quality and accessibility of behavioral interventions.

Semantic Variant Primary Progressive Aphasia: Practical Recommendations for Treatment from 20 Years of Behavioural Research

People with semantic variant primary progressive aphasia (svPPA) present with a characteristic progressive breakdown of semantic knowledge. There are currently no pharmacological interventions to cure or slow svPPA, but promising behavioural approaches are increasingly reported. This article offers an overview of the last two decades of research into interventions to support language in people with svPPA including recommendations for clinical practice and future research based on the best available evidence. We offer a lay summary in English, Spanish and French for education and dissemination purposes. This paper discusses the implications of right- versus left-predominant atrophy in svPPA, which naming therapies offer the best outcomes and how to capitalise on preserved long-term memory systems. Current knowledge regarding the maintenance and generalisation of language therapy gains is described in detail along with the development of compensatory approaches and educational and support group programmes. It is concluded that there is evidence to support an integrative framework of treatment and care as best practice for svPPA. Such an approach should combine rehabilitation interventions addressing the language impairment, compensatory approaches to support activities of daily living and provision of education and support within the context of dementia.

Treatment for Anomia in Bilingual Speakers with Progressive Aphasia

Anomia is an early and prominent feature of primary progressive aphasia (PPA) and other neurodegenerative disorders. Research investigating treatment for lexical retrieval impairment in individuals with progressive anomia has focused primarily on monolingual speakers, and treatment in bilingual speakers is relatively unexplored. In this series of single-case experiments, 10 bilingual speakers with progressive anomia received lexical retrieval treatment designed to engage relatively spared cognitive-linguistic abilities and promote word retrieval. Treatment was administered in two phases, with one language targeted per phase. Cross-linguistic cognates (e.g., rose and rosa) were included as treatment targets to investigate their potential to facilitate cross-linguistic transfer. Performance on trained and untrained stimuli was evaluated before, during, and after each phase of treatment, and at 3, 6, and 12 months post-treatment. Participants demonstrated a significant treatment effect in each of their treated languages, with maintenance up to one year post-treatment for the majority of participants. Most participants showed a significant cross-linguistic transfer effect for trained cognates in both the dominant and nondominant language, with fewer than half of participants showing a significant translation effect for noncognates. A gradual diminution of translation and generalization effects was observed during the follow-up period. Findings support the implementation of dual-language intervention approaches for bilingual speakers with progressive anomia, irrespective of language dominance.

A Systematic Review of Transcranial Direct Current Stimulation in Primary Progressive Aphasia: Methodological Considerations

A variety of tDCS approaches has been used to investigate the potential of tDCS to improve language outcomes, or slow down the decay of language competences caused by Primary Progressive Aphasia (PPA). The employed stimulation protocols and study designs in PPA are generally speaking similar to those deployed in post-stroke aphasic populations. These two etiologies of aphasia however differ substantially in their pathophysiology, and for both conditions the optimal stimulation paradigm still needs to be established. A systematic review was done and after applying inclusion and exclusion criteria, 15 articles were analyzed focusing on differences and similarities across studies especially focusing on PPA patient characteristics (age, PPA variant, language background), tDCS stimulation protocols (intensity, frequency, combined therapy, electrode configuration) and study design as recent reviews and group outcomes for individual studies suggest tDCS is an effective tool to improve language outcomes, while methodological approach and patient characteristics are mentioned as moderators that may influence treatment effects. We found that studies of tDCS in PPA have clinical and methodological and heterogeneity regarding patient populations, stimulation protocols and study design. While positive group results are usually found irrespective of these differences, the magnitude, duration and generalization of these outcomes differ when comparing stimulation locations, and when results are stratified according to the clinical variant of PPA. We interpret the results of included studies in light of patient characteristics and methodological decisions. Further, we highlight the role neuroimaging can play in study protocols and interpreting results and make recommendations for future work.

Cognitive Intervention Strategies Directed to Speech and Language Deficits in Primary Progressive Aphasia: Practice-Based Evidence from 18 Cases

BACKGROUND

Practice-based evidence can inform and support clinical decision making. Case-report series about the implementation of programs in real-world clinical settings may contribute to verifying the effectiveness of interventions for treating PPA in specific contexts, as well as illustrating challenges that need to be overcome.

OBJECTIVE

To describe and provide practice-based evidence on the effectiveness of four cognitive rehabilitation programs designed for individuals with PPA and directed to speech and language impairments, which were implemented in a specialized outpatient clinic.

METHODS

Multiple single-case study. Eighteen individuals with different subtypes of PPA were each assigned to one out of four training programs based on comprehensive speech and language assessments. The treatments targeted naming deficits, sentence production, speech apraxia, and phonological deficits. Pre- and post-treatment assessments were undertaken to compare trained and untrained items. Gains were generalized to a different task in the first two types of intervention (naming and sentence production). A follow-up assessment was conducted 1-8 months after treatment among 7 participants.

RESULTS

All individuals presented better performance in the trained items at the post-test for each rehabilitation program accomplished, demonstrating that learning of the trained strategies was achieved during the active phase of treatment. For 13 individuals, statistical significance was reached; while for five, the results were maintained. Results about untrained items, generalization to other tasks, and follow-up assessments are presented.

CONCLUSIONS

The positive results found in our sample bring some practice-based evidence for the benefits of speech and language treatment strategies for clinical management of individuals with PPA.

Language training for oral and written naming impairment in primary progressive aphasia: a review

BACKGROUND

Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by a gradual, insidious and progressive loss of language abilities, with naming difficulties being an early and persistent impairment common to all three variants. In the absence of effective pharmacological treatments and given the progressive nature of the disorder, in the past few decades, many studies have investigated the effectiveness of language training to minimize the functional impact of word-finding difficulties in daily life.

MAIN BODY

We review language treatments most commonly used in clinical practice among patients with different variants of PPA, with a focus on the enhancement of spoken and written naming abilities. Generalization of gains to the ability to name untrained stimuli or to other language abilities and the maintenance of these results over time are also discussed. Forty-eight studies were included in this literature review, identifying four main types of language treatment: a) lexical retrieval treatment, b) phonological and/or orthographic treatment, c) semantic treatment, and d) a multimodality approach treatment. Overall, language training is able to induce immediate improvements of naming abilities in all variants of PPA. Moreover, despite the large variability among results, generalization and long-term effects can be recorded after the training. The reviewed studies also suggest that one factor that determines the choice of a particular approach is the compromised components of the lexical/semantic processing system.

CONCLUSION

The majority of studies have demonstrated improvements of naming abilities following language treatments. Given the progressive nature of PPA, it is essential to apply language treatment in the early stages of the disease.

Is word learning enough? Improved verb phrase production following cueing of verbs and nouns in primary progressive aphasia

There is little evidence that, for people with aphasia, successful outcomes following lexical retrieval treatment generalise beyond single word retrieval to sentence production or daily communication. This study aimed to develop greater understanding of the mechanisms of generalisation. We employed a cueing task to simulate the effects of lexical retrieval treatment. A single noun or verb was provided and the effect on production of a corresponding verb phrase examined. Sixteen individuals with primary progressive aphasia (PPA) were asked to produce verb phrases to describe action pictures accompanied by i) a verb cue where a spoken and written verb was also presented with the picture; ii) a noun cue where a spoken and written noun was presented with the picture; iii) a no cue condition where only the picture was presented. Across the case series, both verb and noun cueing improved verb phrase production relative to no cue, with verb cueing being most effective. At the level of the single case, thirteen individuals showed significantly increased production of verb phrases with verb cueing, and seven individuals with noun cueing. In addition, seven individuals showed significantly greater benefit from verb cueing compared to noun cueing, and none showed the reverse. This suggests that improvements in verb phrase production may also be achievable following treatment-induced improvements in lexical retrieval. Greater benefit from verb cues than noun cues raises important theoretical issues regarding sentence construction and clinical issues around the most effective treatment techniques for people with aphasia.

Exploring the effects of verb and noun treatment on verb phrase production in primary progressive aphasia: A series of single case experimental design studies

Evidence of generalization to connected speech following lexical retrieval treatment in Primary Progressive Aphasia (PPA) is scarce. Consequently, this study systematically investigated changes in verb phrase production following lexical retrieval treatment in a series of single case experimental design studies. Four individuals with PPA (three semantic- and one logopenic variant PPA) who had previously demonstrated that they could integrate verbs and nouns into sentence structures in a cueing paradigm, undertook a sequence of verb and noun lexical retrieval treatments using Repetition and Reading in the Presence of a Picture. Production of treated nouns- and/or verbs-in-isolation significantly improved following treatment for three of the four participants. Verb phrase production did not improve for one of these participants (logopenic PPA), perhaps due to the relatively small treatment dose. Two participants (semantic variant PPA) did, however, demonstrate across-level generalization, with improvement in treated verbs and using those verbs in (untreated) verb phrases. Their verb phrase production improved most after lexical retrieval treatment for both nouns and verbs, suggesting this combined approach may benefit across-level generalization for some individuals in clinical practice.

Evaluating a Maintenance-Based Treatment Approach to Preventing Lexical Dropout in Progressive Anomia

Purpose Primary progressive aphasia (PPA) and the amnestic variant of Alzheimer's disease (AD) are neurodegenerative conditions characterized by a profound loss of functional communication abilities. Communicative impairment in AD and PPA is especially apparent in the domain of naming common objects and familiar faces. We evaluated the effectiveness of a language intervention targeting maintenance of an individualized core vocabulary in a longitudinal cohort of older adults experiencing either PPA or AD. Method PPA (n = 9) and AD (n = 1) patients were administered a semantically based language treatment for up to 2 years. Patients repeatedly named and generated semantic features for a personalized lexicon consisting of 100 words. We evaluated naming accuracy and off-line neuropsychological measures at four successive timepoints. Naming accuracy was assessed in patients (n = 7) who completed at least three recurrent evaluations. Off-line neuropsychological performance was assessed across timepoints in all patients. Results Patients demonstrated relative preservation of naming trained words relative to a steep decline for untrained (control) words. The greatest decrements were observed for naming people relative to objects. Conclusion These results suggest that consistent training of a finite set of words can protect a core lexicon composed of crucial target concepts (e.g., a spouse's name). We discuss potential benefits and clinical implications of maintenance-based approaches to promoting language functioning in the context of neurodegeneration.

Verb-argument integration in primary progressive aphasia: Real-time argument access and selection

BACKGROUND

Impaired sentence comprehension is observed in the three major subtypes of PPA, with distinct performance patterns relating to impairments in comprehending complex sentences in the agrammatic (PPA-G) and logopenic (PPA-L) variants and word comprehension in the semantic subtype (PPA-S). However, little is known about basic combinatory processes during sentence comprehension in PPA, such the integration of verbs with their subject and object(s) (verb-argument integration).

METHODS

The present study used visual-world eye-tracking to examine real-time verb-argument integration in individuals with PPA (12 with PPA-G, 10 with PPA-L, and 6 with PPA-S) and neurotypical older adults (15). Two baseline experiments probed eye movement control, using a non-linguistic task, and noun comprehension, respectively. Two verb-argument integration experiments examined the effects of verb meaning on (a) lexical access of the verb's direct object (argument access) and (b) selection of a semantically-appropriate direct object (argument selection), respectively. Eye movement analyses were conducted only for trials with correct behavioral responses, allowing us to distinguish accuracy and online processing.

RESULTS

The eye movement control experiment revealed no significant impairments in PPA, whereas the noun comprehension experiment revealed reduced accuracy and eye-movement latencies in PPA-S, and to a lesser extent PPA-G. In the argument access experiment, verb meaning facilitated argument access normally in PPA-G and PPA-L; in PPA-S, verb-meaning effects emerged on an atypical time course. In the argument selection experiment, significant impairments in accuracy were observed only in PPA-G, accompanied by markedly atypical eye movement patterns.

CONCLUSION

This study revealed two distinct patterns of impaired verb-argument integration in PPA. In PPA-S, impaired verb-argument integration was observed in the argument access experiment, indicating impairments in basic semantic combinatory processes which likely relate to damage in ventral language pathways. In contrast, listeners with PPA-G showed marked impairments of argument selection, likely relating to damage to left inferior frontal regions.

Treatment for Word Retrieval in Semantic and Logopenic Variants of Primary Progressive Aphasia: Immediate and Long-Term Outcomes

Purpose Recent studies confirm the utility of speech-language intervention in primary progressive aphasia (PPA); however, long-term outcomes, ideal dosage parameters, and relative benefits of intervention across clinical variants warrant additional investigation. The purpose of this study was to determine whether naming treatment affords significant, lasting, and generalized improvement for individuals with semantic and logopenic PPA and whether dosage manipulations significantly affect treatment outcomes. Method Eighteen individuals with PPA (9 semantic and 9 logopenic variant) underwent lexical retrieval treatment designed to leverage spared cognitive-linguistic domains and develop self-cueing strategies to promote naming. One group (n = 10) underwent once-weekly treatment sessions, and the other group (n = 8) received the same treatment with 2 sessions per week and an additional "booster" treatment phase at 3 months post-treatment. Performance on trained and untrained targets/tasks was measured immediately after treatment and at 3, 6, and 12 months post-treatment. Results Outcomes from the full cohort of individuals with PPA showed significantly improved naming of trained items immediately post-treatment and at all follow-up assessments through 1 year. Generalized improvement on untrained items was significant up to 6 months post-treatment. The positive response to treatment was comparable regardless of session frequency or inclusion of a booster phase. Outcomes were comparable across PPA subtypes, as was maintenance of gains over the post-treatment period. Conclusion This study documents positive naming treatment outcomes for a group of individuals with PPA, demonstrating strong direct treatment effects, maintenance of gains up to 1 year post-treatment, and generalization to untrained items. Lexical retrieval treatment, in conjunction with daily home practice, had a strong positive effect that did not require more than 1 clinician-directed treatment session per week. Findings confirm that strategic training designed to capitalize on spared cognitive-linguistic abilities results in significant and lasting improvement, despite ongoing disease progression, in PPA.

Feasibility of Automatic Speech Recognition for Providing Feedback During Tablet-Based Treatment for Apraxia of Speech Plus Aphasia

Purpose Individuals with neurogenic speech disorders require ongoing therapeutic support to achieve functional communication goals. Alternative methods for service delivery, such as tablet-based speech therapy applications, may help bridge the gap and bring therapeutic interventions to the patient in an engaging way. The purpose of this study was to evaluate an iPad-based speech therapy app that uses automatic speech recognition (ASR) software to provide feedback on speech accuracy to determine the ASR's accuracy against human judgment and whether participants' speech improved with this ASR-based feedback. Method Five participants with apraxia of speech plus aphasia secondary to stroke completed an intensive 4-week at-home therapy program using a novel word training app with built-in ASR. Multiple baselines across participants and behaviors designs were employed, with weekly probes and follow-up at 1 month posttreatment. Four sessions a week of 100 practice trials each were prescribed, with 1 being clinician-run and the remainder done independently. Dependent variables of interest were ASR-human agreement on accuracy during practice trials and human-judged word production accuracy over time in probes. Also, user experience surveys were completed immediately posttreatment. Results ASR-human agreement on accuracy averaged ~80%, which is a common threshold applied for interrater agreement. All participants demonstrated improved word production accuracy over time with the ASR-based feedback and maintenance of gains after 1 month. All participants reported enjoying using the app with support of a speech pathologist. Conclusion For these participants with apraxia of speech plus aphasia due to stroke, satisfactory gains were made in word production accuracy with an app-based therapy program providing ASR-based feedback on accuracy. Findings support further testing of this ASR-based approach as a supplement to clinician-run sessions to assist clients with similar profiles in achieving higher amount and intensity of practice as well as empowering them to manage their own therapy program. Supplemental Material https://doi.org/10.23641/asha.8206628.

Progress and Challenges in Frontotemporal Dementia Research: A 20-Year Review

The landscape of frontotemporal dementia (FTD) has evolved remarkably in recent years and is barely recognizable from two decades ago. Knowledge of the clinical phenomenology, cognition, neuroimaging, genetics, pathology of the different subtypes of FTD, and their relations to other neurodegenerative conditions, has increased rapidly, due in part, to the growing interests into these neurodegenerative brain conditions. This article reviews the major advances in the field of FTD over the past 20 years, focusing primarily on the work of Frontier, the frontotemporal dementia clinical research group, based in Sydney, Australia. Topics covered include clinical presentations (cognition, behavior, neuroimaging), pathology, genetics, and disease progression, as well as interventions and carer directed research. This review demonstrates the improvement in diagnostic accuracy and capacity to provide advice on genetic risks, prognosis, and outcome. The next major challenge will be to capitalize on these research findings to develop effective disease modifying drugs, which are currently lacking.

Investigating the utility of teletherapy in individuals with primary progressive aphasia

INTRODUCTION

Primary progressive aphasia (PPA) is a neurodegenerative disorder characterized by progressive deterioration of speech and language. A growing body of research supports the utility of speech and language intervention in individuals with PPA, although access to these services remains limited. One potential means of increasing treatment accessibility is the delivery of treatment via telemedicine. Evidence supports the use of teletherapy in stroke-induced aphasia, but research examining the application of teletherapy in PPA is limited. In the current study, a non-randomized group comparison design was used to evaluate the feasibility and utility of treatment delivered via teletherapy relative to treatment administered in person for individuals with PPA.

METHODS

Two treatment protocols were administered as part of a larger study investigating treatment for speech and language deficits in PPA. Participants with semantic (n=10) and logopenic (n=11) PPA received lexical retrieval treatment and individuals with nonfluent/agrammatic PPA (n=10) received video-implemented script training for aphasia designed to promote speech production and fluency. Treatment was administered via teletherapy for approximately half of the participants receiving each intervention. Treatment outcomes and performance on standardized tests were assessed at pre-treatment and post-treatment, as well as 3, 6, and 12 months post-treatment.

RESULTS

Overall, both treatment approaches resulted in significant gains for primary outcome measures. Critically, comparison of in-person and teletherapy groups revealed comparable outcomes. Generalization to untrained targets and tasks and maintenance of treatment-induced gains were also comparable for traditional vs teletherapy participants.

CONCLUSION

Overall, treatment outcomes were largely equivalent for individuals receiving treatment via teletherapy vs traditional, in-person delivery. Results support the application of teletherapy for administering restitutive interventions to individuals with mild-to-moderate PPA. Potential implications for using teletherapy in the treatment of cognitive-linguistic and motoric impairments in other disorders and suggestions for administering treatment via telemedicine are discussed.

Frontotemporal dementia

Frontotemporal dementia (FTD) is the second commonest cause of young onset dementia. Our understanding of FTD and its related syndromes has advanced significantly in recent years. Among the most prominent areas of progress is the overlap between FTD, MND, and other neurodegenerative conditions at a clinicopathologic and genetic level. In parallel major advances in neuroimaging techniques, the discovery of new genetic mutations as well as the development of potential biomarkers may serve to further expand knowledge of the biologic processes at play in FTD and may in turn propel research toward identifying curative and preventative pharmacologic therapies. The aim of this chapter is to discuss the clinical, pathologic, and genetic complexities of FTD and related disorders.

Treatment for spoken and written word retrieval in the semantic variant of primary progressive aphasia

This study investigated whether a treatment programme for spoken word retrieval, supplemented with written naming, was beneficial for an individual with right-hemisphere dominant semantic variant of PPA (svPPA). Assessment and treatment were delivered remotely through Skype. Treatment consisted of two phases of lexical retrieval therapy (Repetition and Reading in the Presence of a Picture: RRIPP), with and without written responses (Phases 1 and 2 respectively), and a third treatment phase based on the procedures of Conceptual Enrichment (COEN) therapy. The first two phases of treatment resulted in short-lasting improvements in spoken and written word retrieval, with greater improvement in Phase 2 when written production was also required. Both treatment phases resulted in gains only for treated items, but generalised to different depictions to those treated. However, Phase 2 also resulted in significant improvement of treated items on a comprehension task. COEN treatment did not result in significant gains in word retrieval or comprehension. This study reinforces the value of a simple lexical retrieval treatment delivered remotely. It adds to the current evidence that anomia in svPPA can be responsive to treatment, but also shows that challenges remain regarding maintenance effects and the generalisation of treatment effects to connected speech.

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

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.

Generalization and maintenance of treatment gains in primary progressive aphasia (PPA): a systematic review

BACKGROUND

Cognitive-linguistic treatments and interventions targeting communication have been developed within the context of primary progressive aphasia (PPA), however knowledge about the scope of generalization and maintenance of therapy gains considering PPA subtypes remains scarce and awaits systematic investigation.

AIMS

To analyse the effects of semantic therapy on generalization and maintenance of treatment outcomes in individuals with PPA, considering its different subtypes.

METHODS & PROCEDURES

Central, PubMed, Medline, Web of Knowledge and Scopus were used to retrieve articles of interest. A total of 25 non-randomized studies published between 2000 and 2016 met the eligibility criteria and therefore were included in this study.

MAIN CONTRIBUTION

This systematic review provides evidence-based information for clinical practice in PPA. Generalization and maintenance effects post-treatment for each PPA variant are analysed and discussed. Several factors are described as important to maximize the scope for generalization and maintenance of treatment gains.

CONCLUSIONS & IMPLICATIONS

Generalization is particularly hard to achieve in the semantic variant, as in the face of degraded semantic knowledge learning is rigid and context dependent. In contrast, non-fluent and logopenic variants offer better scope for generalization. Maintenance patterns do not seem to be influenced by PPA subtype, but rather by other factors such as continued practice, treatment length and frequency of sessions. In the future, clinicians should consider the PPA subtype when planning the treatment protocol.

Comparing the effects of clinician and caregiver-administered lexical retrieval training for progressive anomia

There is a growing body of literature indicating that lexical retrieval training can result in improved naming ability in individuals with neurodegenerative disease. Traditionally, treatment is administered by a speech-language pathologist, with little involvement of caregivers or carry-over of practice into the home. This study examined the effects of a lexical retrieval training programme that was implemented first by a clinician and, subsequently, by a trained caregiver. Two dyads, each consisting of one individual with anomia caused by neurodegenerative disease (one with mild cognitive impairment and one with logopenic primary progressive aphasia) and their caregiver, participated in the study. Results indicated medium and large effect sizes for both clinician- and caregiver-trained items, with generalisation to untrained stimuli. Participants reported improved confidence during communication as well as increased use of trained communication strategies after treatment. This study is the first to document that caregiver-administered speech and language intervention can have positive outcomes when paired with training by a clinician. Caregiver-administered treatment may be a viable means of increasing treatment dosage in the current climate of restricted reimbursement, particularly for patients with progressive conditions.

Relearning and Retaining Personally-Relevant Words using Computer-Based Flashcard Software in Primary Progressive Aphasia

Although anomia treatments have often focused on training small sets of words in the hopes of promoting generalization to untrained items, an alternative is to directly train a larger set of words more efficiently. The current case study reports on a novel treatment for a patient with semantic variant Primary Progressive Aphasia (svPPA), in which the patient was taught to make and practice flashcards for personally-relevant words using an open-source computer program (Anki). Results show that the patient was able to relearn and retain a large subset of her studied words for up to 20 months, the full duration of the study period. At the end of treatment, she showed good retention for 139 words. While only a subset of the 591 studied overall, this is still far more words than is typically targeted in svPPA interventions. Furthermore, she showed evidence of generalization to perceptually distinct stimuli during confrontation naming and temporary gains in semantic fluency, suggesting limited gains in semantic knowledge as a result of training. This case represents a successful example of patient-centered treatment, where the patient used a computer-based intervention independently at home. It also illustrates how data captured from computer-based treatments during routine clinical care can provide valuable “practice-based evidence” for motivating further treatment research.

"Knowing What You Don't Know": Language Insight in Semantic Dementia

BACKGROUND

Reduced insight commonly occurs in dementia and can be specific to one area of functioning. Despite recent models identifying a role for semantic memory, little investigation of insight has been conducted in semantic dementia (SD), with patients often described as being aware of their language problems.

OBJECTIVE

This study aims to investigate language insight in SD.

METHOD

Twenty-two SD (n = 11 severe, n = 11 mild-moderate) and 9 nonfluent primary progressive aphasic patients completed three experimental language tasks to assess knowledge and awareness of certain words. Skills in evaluating language were tested by comparing performance ratings on the Cookie Theft task with objective scoring. Awareness regarding the existence and previous use of certain words was tested using two additional tasks.

RESULTS

While SD patients were as accurate as nonfluent patients in rating their own performance on the Cookie Theft immediately following the task, they were significantly poorer at evaluating the same content re-recorded, or other examples of poor language. Compared to nonfluent patients, severe SD patients also made more errors identifying previously known low frequency words. Lastly, when tested on labels for specific aspects of an object, only SD patients made errors regarding the existence, or their past knowledge, of certain words.

CONCLUSION

SD patients show a general awareness of their language impairments, but have difficulty evaluating language content. These difficulties adversely affect the ability to reflect upon current and past language skills producing an under-awareness of language deficits. This mild, secondary form of anosognosia appears to increase with greater levels of semantic impairment.

Behavioral/Nonpharmacological Approaches to Addressing Cognitive-Linguistic Symptoms in Individuals With Dementia

Despite current barriers to developing and implementing nonpharmacological or behavioral cognitive-linguistic treatments for dementia, a growing evidence base indicates that individuals with dementia may indeed benefit from a range of nonpharmacological intervention approaches in terms of helping them maintain and/or improve their language and cognitive abilities as well as general functioning and emotional well being. With respect to the current dementia literature, this article describes restorative and compensatory approaches for cognitive symptoms, including direct stimulation of cognitive functions and internal and external strategies to maximize use of residual cognitive skills. We also summarize various language treatment techniques designed to address word retrieval deficits or functional communication issues in a range of dementia types and severity. Broader stimulation approaches such as Montessori-based treatment, reminiscence therapy, and exercise/movement therapy are also reviewed given their potential to benefit not only the cognitive-linguistic symptoms of individuals with dementia, but also other aspects of physical, emotional, and behavioral functioning. Last, we conclude by highlighting limitations in the current research literature along with factors to consider for maximizing nonpharmacological treatment effects (i.e., generalization and maintenance of treatment gains) in clinical or research settings.

Prophylaxis and remediation of anomia in the semantic and logopenic variants of primary progressive aphasia

This study evaluated the efficacy of phonological and orthographic treatments for anomia in the semantic and logopenic variants of primary progressive aphasia (svPPA and lvPPA, respectively). Both treatments were administered for 6 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). Oral naming accuracy was measured for trained and untrained picture exemplars, as well as matched items from an untrained condition (UC). Written naming and scene description tasks were also conducted. For all tasks, the change in naming accuracy from baseline to 1 month post-treatment was compared between the UC and each treatment condition. These comparisons indicated that both treatments were effective in the remediation and prophylaxis of anomia in both variants. Furthermore, generalisation to untrained exemplars occurred in both subtypes, whereas item generalisation occurred in lvPPA, and task generalisation was present in svPPA.

Frontotemporal dementia: diagnosis, deficits and management

Frontotemporal dementia (FTD) is a progressive neurologic syndrome with diverse clinical presentations and attendant underlying pathologies. Psychiatric prodrome, neuropsychiatric symptoms and language difficulties are common in FTD, but the diversity of presentation raises unique diagnostic challenges that can significantly impact patient care and counsel for caregivers regarding clinical status and prognosis. While neuropsychiatric symptom measures are helpful, more sensitive assessments delineating the specific behavioral and linguistic deficits accompanying FTD are needed. Comprehensive clinical assessment in combination with evaluation of language, socio-emotional functioning, cognition and neuroimaging aid in accurate and early diagnosis and treatment planning. In what follows, we review each of the FTD syndromes, highlight current research investigating the cognitive, behavioral and socio-emotional deficits observed with this disease, address common diagnostic challenges and summarize best practices associated with management of FTD.

How to constrain and maintain a lexicon for the treatment of progressive semantic naming deficits: Principles of item selection for formal semantic therapy

The progressive degradation of semantic memory is a common feature of many forms of dementia, including Alzheimer's disease and the semantic variant of primary progressive aphasia (svPPA). One of the most functionally debilitating effects of this semantic impairment is the inability to name common people and objects (i.e., anomia). Clinical management of a progressive, semantically based anomia presents extraordinary challenges for neurorehabilitation. Techniques such as errorless learning and spaced-retrieval training show promise for retraining forgotten words. However, we lack complementary detail about what to train (i.e., item selection) and how to flexibly adapt the training to a declining cognitive system. This position paper weighs the relative merits of several treatment rationales (e.g., restore vs. compensate) and advocates for maintenance of known words over reacquisition of forgotten knowledge in the context of semantic treatment paradigms. I propose a system for generating an item pool and outline a set of core principles for training and sustaining a micro-lexicon consisting of approximately 100 words. These principles are informed by lessons learned over the course of a Phase I treatment study targeting language maintenance over a 5-year span in Alzheimer's disease and SvPPA. Finally, I propose a semantic training approach that capitalises on lexical frequency and repeated training on conceptual structure to offset the loss of key vocabulary as disease severity worsens.

Vocabulary relearning in semantic dementia: Positive and negative consequences of increasing variability in the learning experience

Anomia therapy typically aims to improve patients' communication ability through targeted practice in naming a set of particular items. For such interventions to be of maximum benefit, the use of trained (or relearned) vocabulary must generalise from the therapy setting into novel situations. We investigated relearning in three patients with semantic dementia, a condition that has been associated with poor generalisation of relearned vocabulary. We tested two manipulations designed to improve generalisation of relearned words by introducing greater variation into the learning experience. In the first study, we found that trained items were retained more successfully when they were presented in a variety of different sequences during learning. In the second study, we found that training items using a range of different pictured exemplars improved the patients' ability to generalise words to novel instances of the same object. However, in one patient this came at the cost of inappropriate over-generalisations, in which trained words were incorrectly used to name semantically or visually similar objects. We propose that more variable learning experiences benefit patients because they shift responsibility for learning away from the inflexible hippocampal learning system and towards the semantic system. The success of this approach therefore depends critically on the integrity of the semantic representations of the items being trained. Patients with naming impairments in the context of relatively mild comprehension deficits are most likely to benefit from this approach, while avoiding the negative consequences of over-generalisation.

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SD patients attempted to recover lost vocabulary by naming pictures daily.

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Learning was more successful when pictures presented in a different order each day.

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One patient benefitted from naming multipleexemplars of each item.

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But in the other patient, this resulted in over-generalisation of the trained name.

Prophylactic Treatments for Anomia in the Logopenic Variant of Primary Progressive Aphasia: Cross-Language Transfer

BACKGROUND

Treatment studies for anomia in 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.

Rehabilitation of lexical and semantic communicative impairments: An overview of available approaches

Lexical-semantic impairments are common consequences of acquired neurological damage. However, little is known about the benefits of existing treatment methods for this type of language impairment.