Treatment for anomia 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.

Multifocal Transcranial Direct Current Stimulation in Primary Progressive Aphasia Does Not Provide a Clinical Benefit Over Speech Therapy

BACKGROUND

Primary progressive aphasia (PPA) is a group of neurodegenerative disorders including Alzheimer's disease and frontotemporal dementia characterized by language deterioration. Transcranial direct current stimulation (tDCS) is a non-invasive intervention for brain dysfunction.

OBJECTIVE

To evaluate the tolerability and efficacy of tDCS combined with speech therapy in the three variants of PPA. We evaluate changes in fMRI activity in a subset of patients.

METHODS

Double-blinded, randomized, cross-over, and sham-controlled tDCS study. 15 patients with PPA were included. Each patient underwent two interventions: a) speech therapy + active tDCS and b) speech therapy + sham tDCS stimulation. A multifocal strategy with anodes placed in the left frontal and parietal regions was used to stimulate the entire language network. Efficacy was evaluated by comparing the results of two independent sets of neuropsychological assessments administered at baseline, immediately after the intervention, and at 1 month and 3 months after the intervention. In a subsample, fMRI scanning was performed before and after each intervention.

RESULTS

The interventions were well tolerated. Participants in both arms showed clinical improvement, but no differences were found between active and sham tDCS interventions in any of the evaluations. There were trends toward better outcomes in the active tDCS group for semantic association and reading skills. fMRI identified an activity increase in the right frontal medial cortex and the bilateral paracingulate gyrus after the active tDCS intervention.

CONCLUSION

We did not find differences between active and sham tDCS stimulation in clinical scores of language function in PPA patients.

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.

Multimodality Imaging in Primary Progressive Aphasia

Primary progressive aphasia is a clinically and neuropathologically heterogeneous group of progressive neurodegenerative disorders, characterized by language-predominant impairment and commonly associated with atrophy of the dominant language hemisphere. While this clinical entity has been recognized dating back to the 19th century, important advances have been made in defining our current understanding of primary progressive aphasia, with 3 recognized subtypes to date: logopenic variant, semantic variant, and nonfluent/agrammatic variant. Given the ongoing progress in our understanding of the neurobiology and genomics of these rare neurodegenerative conditions, accurate imaging diagnoses are of the utmost importance and carry implications for future therapeutic triaging. This review covers the diverse spectrum of primary progressive aphasia and its multimodal imaging features, including structural, functional, and molecular neuroimaging findings; it also highlights currently recognized diagnostic criteria, clinical presentations, histopathologic biomarkers, and treatment options of these 3 primary progressive aphasia subtypes.

Sleep as a predictor of tDCS and language therapy outcomes

STUDY OBJECTIVES

To determine whether sleep at baseline (before therapy) predicted improvements in language following either language therapy alone or coupled with transcranial direct current stimulation (tDCS) in individuals with primary progressive aphasia (PPA).

METHODS

Twenty-three participants with PPA (mean age 68.13 ± 6.21) received written naming/spelling therapy coupled with either anodal tDCS over the left inferior frontal gyrus (IFG) or sham condition in a crossover, sham-controlled, double-blind design (ClinicalTrials.gov identifier: NCT02606422). The outcome measure was percent of letters spelled correctly for trained and untrained words retrieved in a naming/spelling task. Given its particular importance as a sleep parameter in older adults, we calculated sleep efficiency (total sleep time/time in bed x100) based on subjective responses on the Pittsburgh Sleep Quality Index (PSQI). We grouped individuals based on a median split: high versus low sleep efficiency.

RESULTS

Participants with high sleep efficiency benefited more from written naming/spelling therapy than participants with low sleep efficiency in learning therapy materials (trained words). There was no effect of sleep efficiency in generalization of therapy materials to untrained words. Among participants with high sleep efficiency, those who received tDCS benefitted more from therapy than those who received sham condition. There was no additional benefit from tDCS in participants with low sleep efficiency.

CONCLUSION

Sleep efficiency modified the effects of language therapy and tDCS on language in participants with PPA. These results suggest sleep is a determinant of neuromodulation effects.Clinical Trial: tDCS Intervention in Primary Progressive Aphasia https://clinicaltrials.gov/ct2/show/NCT02606422.

Many Changes in Speech through Aging Are Actually a Consequence of Cognitive Changes

Background: During aging, changes in human speech may arise because of the neurophysiological deterioration associated with age, or as the result of an impairment in the cognitive processes underlying speech production. Some speech parameters show specific alterations under the presence of dementia. The objective of our study is to identify which of these parameters change because of age, cognitive state, or the interaction of both. Methods: The sample includes 400 people over 55 years old, who were divided into four groups, according to their age. The cognitive state of the participants was assessed through the MMSE test and three ranks were stablished. Gender was also considered in the analysis. Results: Certain temporal, fluency, rhythm, amplitude and voice quality parameters were found to be related to the cognitive state, while disturbance parameters changed due to age. Frequency parameters were exclusively influenced by gender. Conclusions: Understanding how speech parameters are specifically affected by age, cognitive state, or the interaction of both, is determinant to advance in the use of speech as a clinical marker for the detection of cognitive impairments.

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.

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.

Errorless Learning Therapy in Semantic Variant of Primary Progressive Aphasia

BACKGROUND

The semantic variant of primary progressive aphasia (svPPA) is characterized by a progressive loss of semantic knowledge impairing the ability to name and to recognize the meaning of words.

OBJECTIVE

We aimed to evaluate the immediate and short-term effect of errorless learning speech therapy on the naming and recognition of commonly used words in patients with svPPA.

METHODS

Eight participants diagnosed with svPPA received 16 sessions of intensive errorless learning speech therapy. Naming and word comprehension tasks were evaluated at baseline, immediately postintervention, and at follow-up after 1, 3, and 6 months. These evaluations were performed using two item sets (a trained list and an untrained list).

RESULTS

In the naming tasks, patients showed a significant improvement in trained items immediately after the intervention, but that improvement decayed progressively when therapy ended. No improvements were found either in trained comprehension or in untrained tasks.

CONCLUSION

Errorless learning therapy could improve naming ability in patients with svPPA. This effect may be due to the relative preservation of episodic memory, but the benefit is not maintained over time, presumably because there is no consolidation.

Methodological Considerations for Incorporating Clinical Data Into a Network Model of Retrieval Failures

Difficulty retrieving information (e.g., words) from memory is prevalent in neurogenic communication disorders (e.g., aphasia and dementia). Theoretical modeling of retrieval failures often relies on clinical data, despite methodological limitations (e.g., locus of retrieval failure, heterogeneity of individuals, and progression of disorder/disease). Techniques from network science are naturally capable of handling these limitations. This paper reviews recent work using a multiplex lexical network to account for word retrieval failures and highlights how network science can address the limitations of clinical data. Critically, any model we employ could impact clinical practice and patient lives, harkening the need for theoretically well-informed network models.

Western Aphasia Battery-Revised Profiles in Primary Progressive Aphasia and Primary Progressive Apraxia of Speech

Purpose The primary aim was to examine the utility of the Western Aphasia Battery-Revised (WAB-R; Kertesz, 2007) for classifying variants of primary progressive aphasia (PPA). Traditional WAB-R metrics of Aphasia Quotient (AQ), subtest scores, WAB-R classification, and several novel metrics were examined. A secondary aim was to examine these same WAB-R metrics in individuals with primary progressive apraxia of speech (PPAOS). Method A retrospective analysis of WAB-R records from 169 participants enrolled in a study of neurodegenerative speech and language disorders was conducted. PPA/PPAOS classification was determined by consensus review of speech, language, and cognitive profiles. Scores on each of the WAB-R subtests were obtained to derive AQ, WAB-R aphasia profile, and 3 ratios reflecting relative performance on subtests. Results Mean AQ was significantly higher in the PPAOS group compared to all PPA variants except primary fluent aphasia. AQ above the normal cutoff was observed for 20% of participants with PPA. Significant main effects of group were noted for each of the subtests. Follow-up comparisons most frequently discriminated PPAOS, primary agrammatic aphasia (PAA), and logopenic progressive aphasia. Primary fluent aphasia and semantic dementia (SD) subtest scores were less distinctive, with the exception of Naming for SD, which was significantly lower than for PAA and PPAOS. When the WAB-R AQ detected aphasia, a classification of anomic aphasia was most frequently observed; this pattern held true for each of the PPA variants. The mean Information Content:Naming ratio was highest for SD, and the mean Comprehension:Fluency ratio was highest for PAA. Conclusions In the current study, AQ underestimated the presence of PPA and WAB-R classification did not distinguish among PPA classification determined by consensus. Performance on individual subtests and relative performance across subtests demonstrated inconsistent alignment with PPA classification. We conclude the WAB-R in isolation is inadequate to detect or characterize PPA. We instead suggest utilizing the WAB-R as 1 component of a comprehensive language and motor speech assessment when PPA is suspected.

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.

Communication Bridge: A pilot feasibility study of Internet-based speech-language therapy for individuals with progressive aphasia

Introduction

Individuals with aphasia symptoms due to neurodegenerative disease are under-referred for speech–language therapy (SLT) services. We sought to determine the feasibility of utilizing telepractice, via Internet videoconferencing, to connect individuals with progressive aphasia to a speech–language pathologist (SLP) for treatment.

Methods

Participants received an initial evaluation, 8 person-centered Internet-based SLT sessions, and 2 post-therapy evaluations. The feasibility of providing Web-based SLT, strategies used and their compliance, functional gains, and the duration of benefit were assessed.

Results

Thirty-four participants from 21 states and Canada were enrolled. Thirty-one participants completed the 6-month evaluation. SLP-assessed and self-reported functional gains and increased confidence in communication were documented at 2 months and maintained at 6 months postenrollment.

Discussion

Internet-based SLT using person-centered interventions provides a feasible model for delivering care to individuals with dementia and mild and/or moderate aphasia symptoms who have an engaged care-partner and prior familiarity with a computer.

Exploring generalisation processes following lexical retrieval intervention in primary progressive aphasia

PURPOSE

Within the current literature, positive intervention effects demonstrate the significant potential for people with Primary Progressive Aphasia (PPA) to learn/relearn words. Generalisation of intervention effects to other words and/or other contexts, however, remains unclear.

METHOD

This multiple baseline, case-series design investigated the effects of a self-cueing lexical retrieval intervention across word classes (nouns, verbs and adjectives) on four individuals with PPA, three suggestive of the semantic variant and one of the logopenic variant. The intervention integrated semantic, phonological and orthographic levels of language production and drew on autobiographical memory. Changes in accuracy in retrieving treated and untreated items (pre-intervention, post-intervention and 4-weeks maintenance) were determined using the Cochran's Q test, with follow-up McNemar pairwise comparisons.

RESULT

All participants showed significant improvements in naming treated items, across all word classes. Different patterns of generalised improvement to untreated words were found for each participant. In discourse, the semantic variant participants demonstrated a significant increase in correct information units, in contrast to the participant with the logopenic variant who remained stable.

CONCLUSION

This study provides evidence that people with PPA can show improved lexical retrieval following intervention. The findings suggest possible differences in generalisation across word classes and according to underlying deficit.

Memory dysfunction

PURPOSE OF REVIEW

This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system.

RECENT FINDINGS

Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails.

SUMMARY

Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment.

Treatment of Primary Progressive Aphasia

OPINION STATEMENT

Primary progressive aphasia (PPA) is a neurodegenerative disease that primarily affects language functions and often begins in the fifth or sixth decade of life. The devastating effects on work and home life call for the investigation of treatment alternatives. In this paper, we present a review of the literature on treatment approaches for this neurodegenerative disease. We also present new data from two intervention studies we have conducted, a behavioral one and a neuromodulatory one using transcranial direct current stimulation (tDCS) combined with written production intervention. We show that speech-language intervention improves language outcomes in individuals with PPA, and especially in the short term, tDCS augments generalization and maintenance of positive language outcomes. We also outline current issues and challenges in intervention approaches in PPA.

Neuropsychiatric management of young-onset dementias

A combination of pharmacologic and nonpharmacologic approaches is necessary for the appropriate neuropsychiatric management of patients with young-onset dementia. Nonpharmacologic interventions, including psychological management, environmental strategies, and caregiver's support, should be the first choice for neuropsychiatric management. Pharmacologic interventions differ according to the underlying causes of dementia; thus, differential diagnoses are very important. Antipsychotics should be prescribed carefully; they should be used for the shortest time possible, at the lowest possible dose.

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.

Improving verb anomia in the semantic variant of primary progressive aphasia: the effectiveness of a semantic-phonological cueing treatment

The semantic variant of primary progressive aphasia (svPPA) is known to affect the comprehension and production of all content words, including verbs. However, studies of the treatment of anomia in this disorder focused on relearning object names only. This study reports treatment of verb anomia in an individual with svPPA. The semantic-phonological cueing therapy resulted in significant improvement in naming abilities, for treated verbs only. This case study demonstrates that improvement in verb-naming abilities may be possible in svPPA. The almost complete maintenance of the treatment's effects in the patient 4 weeks after the end of the therapy also suggests improvements may be durable, at least in the short term, for some individuals with svPPA.

Supporting communication for patients with neurodegenerative disease

BACKGROUND

Communication supports, referred to as augmentative and alternative communication (AAC), are an integral part of medical speech-language pathology practice, yet many providers remain unfamiliar with assessment and intervention principles. For patients with complex communication impairments secondary to neurodegenerative disease, AAC services differ depending on whether their condition primarily affects speech and motor skills (ALS), language (primary progressive aphasia) or cognition (Alzheimer's disease). This review discusses symptom management for these three conditions, identifying behavioral strategies, low- and high-tech solutions for implementation during the natural course of disease. These AAC principles apply to all neurodegenerative diseases in which common symptoms appear.

OBJECTIVES

To present AAC interventions for patients with neurodegenerative diseases affecting speech, motor, language and cognitive domains. Three themes emerge: (1) timing of intervention: early referral, regular re-evaluations and continual treatment are essential; (2) communication partners must be included from the onset to establish AAC acceptance and use; and (3) strategies will change over time and use multiple modalities to capitalize on patients' strengths.

CONCLUSIONS

AAC should be standard practice for adults with neurodegenerative disease. Patients can maintain effective, functional communication with AAC supports. Individualized communication systems can be implemented ensuring patients remain active participants in daily activities.

Treatment for Lexical Retrieval in Primary Progressive Aphasia

In recent years there has been an increase in research describing the behavioral characteristics and underlying pathology of primary progressive aphasia (PPA). One of the earliest and most prominent features of PPA, particularly for the logopenic and semantic variants, is anomia, and this is often the symptom that prompts individuals with PPA to seek treatment. However, speech-language pathologists who encounter individuals with PPA on their clinical caseloads often have questions about how best to manage progressive language decline in these patients. A small body of literature suggests that treatment for anomia in PPA is indeed warranted, and that item-specific improvement can be expected for a majority of individuals receiving treatment. Although generalization and maintenance of treatment gains are variable in the face of progressive decline, there are some emerging themes as to treatment approaches and patient characteristics that may promote more generalized and relatively durable treatment outcomes. Ultimately, treatment that engages residual semantic, phonologic and orthographic skills, using both strategic training and stimulation, may be appropriate for PPA patients with mild-moderate anomia.

Augmentation of spelling therapy with transcranial direct current stimulation in primary progressive aphasia: Preliminary results and challenges

BACKGROUND

Primary progressive aphasia (PPA) is a neurodegenerative disease that primarily affects language functions and often begins in the fifth or sixth decade of life. The devastating effects on work and family life call for the investigation of treatment alternatives. In this article, we present new data indicating that neuromodulatory treatment, using transcranial direct current stimulation (tDCS) combined with a spelling intervention, shows some promise for maintaining or even improving language, at least temporarily, in PPA.

AIMS

The main aim of the present article is to determine whether tDCS plus spelling intervention is more effective than spelling intervention alone in treating written language in PPA. We also asked whether the effects of tDCS are sustained longer than the effects of spelling intervention alone.

METHODS & PROCEDURES

We present data from six PPA participants who underwent anodal tDCS or sham plus spelling intervention in a within-subject crossover design. Each stimulation condition lasted 3 weeks or a total of 15 sessions with a 2-month interval in between. Participants were evaluated on treatment tasks as well as on other language and cognitive tasks at 2-week and 2-month follow-up intervals after each stimulation condition.

OUTCOMES & RESULTS

All participants showed improvement in spelling (with sham or tDCS). There was no difference in the treated items between the two conditions. There was, however, consistent and significant improvement for untrained items only in the tDCS plus spelling intervention condition. Furthermore, the improvement lasted longer in the tDCS plus spelling intervention condition compared to sham plus spelling intervention condition.

CONCLUSIONS

Neuromodulation with tDCS offers promise as a means of augmenting language therapy to improve written language function at least temporarily in PPA. The consistent finding of generalisation of treatment benefits to untreated items and the superior sustainability of treatment effects with tDCS justifies further investigations. However, the small sample size still requires caution in interpretation. Present interventions need to be optimised, and particular challenges, such as ways to account for the variable effect of degeneration in each individual, are discussed.

Spelling intervention in post-stroke aphasia and primary progressive aphasia

Spelling–a core language skill–is commonly affected in neurological diseases such as stroke and Primary Progressive Aphasia (PPA). We present two case studies of the same spelling therapy (learning of phoneme-to-grapheme correspondences with help from key words) in two participants: one who had a stroke and one with PPA (logopenic variant). Our study highlights similarities and differences in the time course of each indivdual's therapy. The study evaluates the effectiveness and generalization of treatment in each case, i.e. whether the treatment affected the trained items and/or untrained items, and whether or not the treatment gains were maintained after the end of therapy. Both participants were able to learn associations between phonemes and graphemes as well as between phonemes and words. Reliable generalization to untrained words was shown only for the participant with post-stroke aphasia, but we were not able to test generalization to untrained words in the individual with PPA. The same spelling therapy followed a different time course in each case. The participant with post-stroke aphasia showed a lasting effect of improved spelling, but we were unable to assess maintenance of improvement in the participant with PPA. We discuss these differences in light of the underlying nature of each disease.

Behavioural interventions for enhancing life participation in behavioural variant frontotemporal dementia and primary progressive aphasia

Primary progressive aphasia (PPA) and behavioural-variant frontotemporal dementia (bvFTD) are clinical syndromes under the umbrella term 'frontotemporal dementia' (FTD) and are caused by a neurodegenerative disease with an onset most typically in the productive years of adulthood. The cognitive and behavioural impairments associated with FTD interfere with successful engagement in typical life roles, such as parenting, working, and maintenance of interpersonal relationships. There are currently no treatments to stop or slow the degenerative process and there are only very limited medication options for the management of the cognitive-behavioural symptoms. However, alternative, non-pharmacological interventions may offer significant benefit to the quality of life of the diagnosed individual. The goal of this paper is to provide an overview of the approaches available through neurorehabilitation and community-based services that facilitate successful engagement in life activities and promote optimal quality of life for the individuals and families living with FTD. It is hoped that as medical providers become more familiar with behavioural interventions, referrals for services will increase thereby allowing individuals with FTD and their caregivers to learn ways to adapt, adjust, and participate in life to the fullest despite the impairments from this progressive disease.

Positive effects of language treatment for the logopenic variant of primary progressive aphasia

Despite considerable recent progress in understanding the underlying neurobiology of primary progressive aphasia (PPA) syndromes, relatively little attention has been directed toward the examination of behavioral interventions that may lessen the pervasive communication problems associated with PPA. In this study, we report on an individual with a behavioral profile and cortical atrophy pattern consistent with the logopenic variant of PPA. At roughly two-and-a-half years post onset, his marked lexical retrieval impairment prompted administration of a semantically based intervention to improve word retrieval. The treatment was designed to improve self-directed efforts to engage the participant's relatively preserved semantic system in order to facilitate word retrieval. His positive response to an intensive (2-week) dose of behavioral treatment was associated with improved lexical retrieval of items within trained categories, and generalized improvement for naming of untrained items that lasted over a 6-month follow-up interval. These findings support the potential value of intensive training to achieve self-directed strategic compensation for lexical retrieval difficulties in logopenic PPA. Additional insight was gained regarding the neural regions that supported improved performance by the administration of a functional magnetic resonance imaging protocol before and after treatment. In the context of a picture-naming task, post-treatment fMRI showed increased activation of left dorsolateral prefrontal regions that have been implicated in functional imaging studies of generative naming in healthy individuals. The increased activation in these frontal regions that were not significantly atrophic in our patient (as determined by voxel-based morphometry) is consistent with the notion that neural plasticity can support compensation for specific language loss, even in the context of progressive neuronal degeneration.

Cooking "shrimp à la créole": a pilot study of an ecological rehabilitation in semantic dementia

New learning in semantic dementia (SD) seems to be tied to a specific temporal and spatial context. Thus, cognitive rehabilitation could capitalise upon preserved episodic memory and focus on everyday activities which, once learned, will have an impact in everyday life. This pilot study thus explores the effectiveness of an ecological approach in one patient suffering from SD. EC, a 68-year-old woman with SD, stopped cooking complex meals due to a substantial loss of knowledge related to all food types. The therapy consisted of preparing a target recipe. She was asked to generate semantic attributes of ingredients found in one target, one control and two no-therapy recipes. The number of recipes cooked by EC between therapy sessions was computed. She was also asked to prepare a generalisation recipe combining ingredients from the target and control recipes. EC's generated semantic attributes (GSA) of ingredients pertaining to the target and control recipes increased significantly (p < .001), compared to the no-therapy recipes (ps > .79). The proportion of meals cooked also increased significantly (p = .021). For the generalisation recipe, she could not succeed without assistance. Frequent food preparation may have provided EC with new memories about the context, usage and appearance of some concepts. These memories seem very context-bound, but EC nonetheless re-introduced some recipes into her day-to-day life. The impact of these results on the relationship between semantic, episodic and procedural memory is discussed, as well as the relevance of an ecological approach in SD.

The importance of multiple assessments of object knowledge in semantic dementia: the case of the familiar objects task

Semantic dementia (SD) is characterized by a dramatic loss of conceptual knowledge about the meaning of words and the identity of objects. Previous research has suggested that SD patients' knowledge is differentially influenced by the disease and may decline at different degrees depending on a patient's everyday familiarity with certain items. However, no study has examined (a) semantic knowledge deterioration and (b) the potential significance of autobiographical experience for the maintenance of object concepts in the same cohort of SD patients by using comprehensive assessments of different aspects of object knowledge across an experience-based, distributed semantic memory network. Here, we tested four SD patients and three Alzheimer's disease (AD) control patients using a range of tasks - including naming, gesture generation, and autobiographical knowledge - with personally familiar objects or perceptually similar or different object analogs. Our results showed dissociations between performance on naming relative to other assessments of object knowledge between SD and AD patients, though we did not observe a reliable familiar objects advantage. We discuss different factors that may account for these findings, as well as their implications for research on SD.

Rehabilitation in semantic dementia: Study of effectiveness of lexical reacquisition in three patients

Although language rehabilitation in patients with primary progressive aphasia (PPA) is recommended, rehabilitation studies in this clinical syndrome are scarce. Specifically, in relation to semantic dementia (SD), few studies have shown the possibility of lexical relearning.

Objective

To analyze the effectiveness of rehabilitation for lexical reacquisition in SD.

Methods

Three SD patients were submitted to training for lexical reacquisition based on principles of errorless learning. Comparisons between naming performance of treated items (pre and post-training) and non-treated items of the Boston Naming Test (BNT) were made.

Results

All patients improved their performance in naming treated words after intervention. However, decline in performance in naming of non-treated items was observed. Case 1 named zero items at baseline while her performance post-training was 29.4% correct responses without cueing, and 90.7% correct with and without cueing. Case 2 named 6.9% of items correctly at baseline and his performance in post-training was 52.9% without cueing and 87.3%, with and without cueing. Case 3 named zero items at baseline and his performance in post-training was 100% correct responses without cueing. Considering the performance in naming the non-treated items of the BNT, the percentages of correct responses in the first evaluation and in the re-evaluation, respectively were: 16.7% and 8.3% (case 1; 14 month-interval); 26.7% and 11.6% (case 2; 18 month-interval) and 11.6% and 8.3% (case 3; 6 month-interval).

Conclusions

The reacquisition of lost vocabulary may be possible in SD despite progressive semantic deterioration.

Treatment for Progressive Impairments of Language

Primary progressive aphasia (PPA) is a relatively new diagnostic entity, for which few behavioral treatments have been investigated. Recent work has helped to clarify the nature of distinct PPA variants, including a nonfluent variant (NFV-PPA), a logopenic variant (LV-PPA), and a semantic variant (SV-PPA). This paper reviews treatment research to date in each subtype of PPA, including restitutive, augmentative, and functional approaches. The evidence suggests that restitutive behavioral treatment can result in improved or stabilized language performance within treated domains. Specifically, sentence production and lexical retrieval have been addressed in NFV-PPA, whereas lexical retrieval has been the primary object of treatment in LV and SV-PPA. Use of augmentative communication techniques, as well as implementation of functional communication approaches, also may result in improved communication skills in individuals with PPA. The ideal treatment approach may be one that combines restitutive, augmentative, and functional approaches to treatment, in order to maximize residual cognitive-linguistic skills in patients. Additional research is warranted to determine which modes of treatment are most beneficial in each type of PPA at various stages of severity.

Update on frontotemporal dementia

BACKGROUND

Frontotemporal dementia has recently been recognized as a common cause of young-onset dementia.

OBJECTIVE

To review the current approach to the clinical evaluation, understanding of pathophysiology, and management of frontotemporal dementia.

RESULTS

Two main clinical presentations are: (1) behavioral, with impulsive behaviors and disinhibition, change in personality such as apathy and indifference, and poor judgment, and (2) language, with a nonfluent aphasia with anomia (primary progressive aphasia), or a fluent aphasia with early loss of word meaning (semantic dementia). The differential diagnosis includes other neurodegenerative dementias, vascular and other conditions affecting the brain, and psychiatric diseases. Investigations, including neuropsychological testing, and structural and functional brain imaging, may help support the diagnosis. Recent advances in understanding the pathophysiology have suggested that most cases have underlying ubiquitin-positive inclusions, whereas some have tau-positive inclusions. Genetic mutations, particularly on chromosome 17 in the tau or progranulin genes, have been identified. Management includes a trial of symptomatic medications and a multifaceted approach, including environmental modification and long-term care planning.

CONCLUSION

Medical researchers studying frontotemporal dementia aim to identify disease-modifying drugs and, ultimately, a cure for this devastating disease.