Telerehabilitation of Anomia in Primary Progressive Aphasia

BACKGROUND

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

AIMS

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

METHODS & PROCEDURES

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

OUTCOMES & RESULTS

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

CONCLUSIONS

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

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.

Mixed tau and TDP-43 pathology in a patient with unclassifiable primary progressive aphasia

Classifying primary progressive aphasia (PPA) into variants that may predict the underlying pathology is important. However, some PPA patients cannot be classified. A 78-year-old woman had unclassifiable PPA characterized by anomia, dysarthria, and apraxia of speech without agrammatism. Magnetic resonance imaging revealed left mesial temporal atrophy and 18-flourodeoxy-glucose positron emission tomography showed left anterior temporal and posterior frontal (premotor) hypometabolism. Autopsy revealed a mixed tauopathy (argyrophilic grain disease) and transactive response-DNA-binding-protein-43 proteinopathy. Dual pathologies may explain the difficulty classifying some PPA patients and recognizing this will be important as new imaging techniques (particularly tau-positron emission tomography) are introduced and patients begin enrollment in clinical trials targeting the underlying proteinopathy.

The Language Profile of Behavioral Variant Frontotemporal Dementia

BACKGROUND

The language profile of behavioral variant frontotemporal dementia (bvFTD) remains to be fully defined.

OBJECTIVE

We aimed to quantify the extent of language deficits in this patient group.

METHODS

We assessed a cohort of patients with bvFTD (n = 24) in relation to patients with semantic variant primary progressive aphasia (svPPA; n = 14), nonfluent variant primary progressive aphasia (nfvPPA; n = 18), and healthy age-matched individuals (n = 24) cross-sectionally and longitudinally using a comprehensive battery of language and general neuropsychological tests. Neuroanatomical associations of language performance were assessed using voxel-based morphometry of patients' brain magnetic resonance images.

RESULTS

Relative to healthy controls, and after accounting for nonverbal executive performance, patients with bvFTD showed deficits of noun and verb naming and single word comprehension, diminished spontaneous propositional speech, and deterioration in naming performance over time. Within the bvFTD group, patients with MAPT mutations had more severe impairments of noun naming and single word comprehension than patients with C9orf72 mutations. Overall the bvFTD group had less severe language deficits than patients with PPA, but showed a language profile that was qualitatively similar to svPPA. Neuroanatomical correlates of naming and word comprehension performance in bvFTD were identified predominantly in inferior frontal and antero-inferior temporal cortices within the dominant hemispheric language network.

CONCLUSIONS

bvFTD is associated with a language profile including verbal semantic impairment that warrants further evaluation as a novel biomarker.

GBA-associated parkinsonism and dementia: beyond α-synucleinopathies?

BACKGROUND AND PURPOSE

To date the role of GBA mutations beyond α-synucleinopathies in the parkinsonism-dementia spectrum is still unclear. The aim of the study was to screen for GBA mutations in progressive supranuclear palsy (PSP), corticobasal syndrome (CBS), primary progressive aphasia (PPA) and the behavioural variant of frontotemporal dementia (bvFTD).

METHODS

In all, 303 patients with a clinical diagnosis of PSP (n = 157), CBS (n = 39), PPA (n = 35) and bvFTD (n = 72) and 587 neurologically healthy controls were screened for the most common GBA mutations.

RESULTS

GBA mutations were detected in one healthy control and four patients with a clinical diagnosis of PSP (n = 1), probable CBS (n = 2) and PPA (n = 1, with concomitant C9orf72 expansion). Overall the prevalence of GBA mutations was low in non-α-synucleinopathies but significantly higher in the CBS subgroup compared to controls.

CONCLUSION

Although numbers are small, our findings indicate that the clinical phenotype of GBA-associated neurodegenerative disease is more heterogeneous than previously assumed, including phenotypes not usually associated with underlying α-synucleinopathies. This may be of relevance, once causal therapeutic strategies for GBA-associated neurodegenerative disease are developed.

Trajectories of Behavioural Disturbances Across Dementia Types

OBJECTIVE

To replicate a previous finding that the trajectory of the Neuropsychiatric Inventory (NPI) shifts in the sixth year of behavioural variant frontotemporal dementia (bvFTD). We evaluated longitudinal tracking with both the Frontal Behavioural Inventory (FBI) and NPI, comparing bvFTD against other dementias.

METHODS

Chart reviews over two to five years for patients with bvFTD (n=30), primary progressive aphasia (PPA, n=13) and Alzheimer's disease (AD, n=118) at an urban Canadian tertiary clinic specializing in dementia. Linear regressions of the longitudinal data tested predictors of annualized rates of change (ROC) in NPI and FBI total and subscales for apathy and disinhibition among dementia groups.

RESULTS

The mode of the overall sample for the most advanced duration of illness observed was 5 years, with the median at 7 years. We did not find a crescendo-decrescendo pattern in scores although, for bvFTD and AD, high initial scores correlated with ensuing downward ROCs on the NPI and FBI. Educational level showed an influence on disinhibition ROCs. The FBI was no more revealing than the NPI for apathy and disinhibition scores in these dementias.

CONCLUSIONS

A cognitive reserve effect on behavioural disturbance was supported but it may take longer than our 4 years of observing the clinical sample to record inflection points in the behavioural and psychiatric symptoms seen in bvFTD. The current data only imply that both apathy and disinhibition will diminish over the course of dementia.

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.

MRI signatures of the frontotemporal lobar degeneration continuum

OBJECTIVE

To identify overlapping and unique grey (GM) and white matter (WM) signatures within the frontotemporal lobar degeneration (FTLD) continuum, and discriminate likely FTLD-TAU and FTLD-TDP patients using structural and diffusion tensor (DT) magnetic resonance imaging (MRI).

METHODS

T1-weighted and DT MRI were collected from 121 subjects: 35 motor neuron disease (MND), 14 behavioral variant of frontotemporal dementia, 12 semantic and 11 nonfluent primary progressive aphasia, 21 progressive supranuclear palsy syndrome patients, and 28 healthy controls. Patterns of GM atrophy were established using voxel-based morphometry. Tract-based spatial statistics was used to perform a WM voxelwise analysis of mean diffusivity and fractional anisotropy.

RESULTS

In all clinical FTLD phenotypes, the pattern of WM damage was more distributed than that of GM atrophy. All patient groups, with the exception of MND cases with a pure motor syndrome, shared a focal GM atrophy centered around the dorsolateral and medial frontal cortex and a largely overlapping pattern of WM damage involving the genu and body of the corpus callosum and ventral frontotemporal and dorsal frontoparietal WM pathways. Surrounding this common area, phenotype (symptom)-specific GM and WM regions of damage were found in each group.

CONCLUSIONS

In the FTLD spectrum, WM disruption is more severe than GM damage. Frontal cortex and WM pathways represent the common target of neurodegeneration in these conditions. The topographic pattern of damage supports a "prion-like" protein propagation through WM connections as underlying mechanism of the stereotyped progression of FTLD.

Neuropsychiatric symptoms in primary progressive aphasia and apraxia of speech

AIM

To conduct a prospective analysis of the neuropsychiatric symptoms (NPS) across the three categories of primary progressive aphasia (PPA) and progressive apraxia of speech (PAOS), compare the prevalence and nature of the symptoms, and look at which symptoms could be helpful to better differentiate these PPA and PAOS categories.

METHODS

A total of 106 consecutive patients with a diagnosis of semantic variant (n = 13), logopenic variant (n = 37), agrammatic variant (n = 15) or PAOS (n = 41) were included in this prospective study. The NPS were measured by the Neuropsychiatric Inventory Questionnaire.

RESULTS

There were 65 patients with PPA and 41 with PAOS diagnosis. The most distinguishing features between the two groups were anxiety, apathy, aberrant motor behavior and appetite, while among the subtypes of PPA they were disinhibition and appetite changes. PPA and PAOS patients initially exhibited depression, but with increased disease duration, PAOS patients showed apathy (55.5%) while PPA patients showed disinhibition (28.6%) and aberrant motor behavior (14.3%).

CONCLUSION

Mood symptoms like anxiety and appetite changes are more likely to be present at initial stages of PPA, whereas behavioral symptoms like aberrant motor behavior and apathy are likely to occur early in PAOS. The NPS seem to evolve with the progression of the disease in both PPA and PAOS.

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.

Improved verbal learning in the semantic variant of primary progressive aphasia when using semantic cues

The semantic variant of primary progressive aphasia (PPA-S) is characterized by impairments in confrontation naming and single word comprehension. Although episodic memory may be relatively spared, there can be impairment in verbal learning tasks. We report a patient with PPA-S and impaired verbal learning who was tested to learn if when provided with semantic categories, her learning would improve. A 70-year-old right-handed woman with a 2-year history of progressive difficulties with word finding, naming, and memory was tested for language and memory deficits using the Hopkins Verbal Learning Test-Revised (HVLT-R). She was then retested with the HVLT-R after being provided with the three semantic categories to which these words belonged. Confrontation naming was impaired on the Boston Naming Test. Sentence repetition was normal. Comprehension testing with word picture matching and sentence comprehension was normal. On a test of semantic associations, Pyramids and Palm Trees, she was impaired. She was also impaired on tests of verbal learning (HVLT-R) (total: 13) but not recall. When a different version of the HVLT-R was given with the semantic categories of the words given beforehand, her scores improved (total: 26). This patient with PPA-S had an impairment of verbal learning, but not delayed recall. When given a semantic category cue beforehand, her verbal learning performance improved. This observation suggests that this patient did not spontaneously use semantic encoding. Using a semantic cueing strategy may help other patients with PPA-S improve their capacity for verbal learning.

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.

Interactions between traumatic brain injury and frontotemporal degeneration

BACKGROUND/AIMS

Prior work in smaller cohorts suggests that traumatic brain injury (TBI) may be a risk factor for frontotemporal degeneration (FTD). We sought to confirm and extend these results using the National Alzheimer's Coordinating Center Uniform Data Set.

METHODS

We compared the TBI prevalence between FTD subjects and matched normal controls. Indices of cognitive, behavioral, functional, and global dementia severity were compared between FTD subjects with and without prior TBI.

RESULTS

Remote TBI with extended loss of consciousness (TBI-ext) was more common in individuals with FTD than in controls (OR: 1.67; 95% CI: 1.004-2.778). With TBI-ext, less functional and global impairment was seen in the behavioral variant of FTD, but more behavioral pathology was seen in the semantic variant.

CONCLUSION

TBI may increase the FTD risk and influence clinical symptomatology and severity in FTD subtypes.

Novel integrative virtual rehabilitation reduces symptomatology of primary progressive aphasia--a case report

PURPOSE

BrightBrainer™ integrative cognitive rehabilitation system evaluation in an Adult Day Program by a subject with Primary Progressive Aphasia (PPA) assumed to be of the mixed nonfluent/logopenic variant, and for determination of potential benefits.

METHODS

The subject was a 51-year-old Caucasian male diagnosed with PPA who had attended an Adult Day Program for 18 months prior to BrightBrainer training. The subject interacted with therapeutic games using a controller that measured 3D hand movements and flexion of both index fingers. The computer simulations adapted difficulty level based on task performance; results were stored on a remote server. The clinical trial consisted of 16 sessions, twice/week for 8 weeks. The subject was evaluated through neuropsychological measures, therapy notes and caregiver feedback forms.

RESULTS

Neuropsychological testing indicated no depression (BDI 0) and severe dementia (BIMS 1 and MMSE 3). The 6.5 h of therapy consisted of games targeting Language comprehension; Executive functions; Focusing; Short-term memory; and Immediate/working memory. The subject attained the highest difficulty level in all-but-one game, while averaging 1300-arm task-oriented active movement repetitions and 320 index finger flexion movements per session. While neuropsychological testing showed no benefits, the caregiver reported strong improvements in verbal responses, vocabulary use, speaking in complete sentences, following one-step directions and participating in daily activities. This corroborated well with therapy notes.

CONCLUSIONS

Preliminary findings demonstrate a meaningful reduction of PPA symptoms for the subject, suggesting follow-up imaging studies to detail neuronal changes induced by BrightBrainer system and controlled studies with a sufficiently large number of PPA subjects.

CSF levels of Aβ1-38/Aβ1-40/Aβ1-42 and (11)C PiB-PET studies in three clinical variants of primary progressive aphasia and Alzheimer's disease

Primary progressive aphasia (PPA) is a cognitive syndrome characterized by progressive and isolated language impairments due to neurodegenerative diseases. Recently, an international group of experts published a Consensus Classification of the three PPA clinical variants (naPPA, svPPA and lvPPA). We analyzed 24 patients with PPA by cognitive functions, neuroimaging (MRI, (99 m)Tc ECD-SPECT, (11)C PiB-PET and FDG-PET) and cerebrospinal fluid (CSF) analysis (ptau-181, Aβ1-42, Aβ1-40 and Aβ1-38), to elucidate relationships between neuroimaging studies and biochemical findings in the three PPA clinical variants. Cognitive and speech functions were measured by mini-mental state examination and standard language test of aphasia. The patients with lvPPA showed significant decreases in CSF Aβ1-42 and ratios of Aβ1-42/Aβ1-40 and Aβ1-42/Aβ1-38, and significant increases in CSF ptau-181 and ratios of ptau-181/Aβ1-42 and ptau-181/Aβ1-38; these findings were similar to those of patients with Alzheimer's disease (AD). We observed a higher frequency of the ApoE ε4 allele in the lvPPA patients relative to the two other PPA variants. In (11)C PiB-PET of lvPPA patients, PiB positive findings were detected in cortices of frontal, temporal and parietal lobes and the posterior cingulate, where massive Aβ may accumulate due to AD. Our results of AD-CSF markers including Aβ1-38 and (11)C PiB-PET in the lvPPA patients demonstrate a common pathological mechanism with the occurrence of AD.

Treatment of frontotemporal dementia

OPINION STATEMENT

Frontotemporal dementia (FTD) encompasses a spectrum of neurodegenerative diseases with heterogeneous clinical presentations and two predominant types of underlying neuropathology. FTD typically comprises three distinct clinical syndromes: behavioral variant frontotemporal dementia (bvFTD), semantic variant primary progressive aphasia (svPPA), and nonfluent variant primary progressive aphasia (nfvPPA). FTD also frequently overlaps both clinically and neuropathologically with three other neurodegenerative syndromes: corticobasal syndrome (CBS), progressive supranuclear palsy (PSP), and amyotrophic lateral sclerosis (ALS). Each syndrome can be associated with one or more underlying neuropathological diagnoses and are referred to as frontotemporal lobar degeneration (FTLD). Although the various FTD syndromes can substantially differ in terms of clinical symptoms and underlying pathology, the symptoms can be broadly categorized into behavioral, cognitive and motor domains. Currently there are no Food and Drug Administration (FDA) approved therapies for the above syndromes except riluzole for ALS. FTD treatment strategies generally rely on off-label use of medications for symptomatic management, and most therapies lack quality evidence from randomized, placebo-controlled clinical trials. For behavioral symptoms, selective serotonin reuptake inhibitors may be effective, while case reports hint at possible efficacy with antipsychotics or anti-epileptics, but use of these latter agents is limited due to concerns regarding side effects. There are no effective therapies for cognitive complaints in FTD, which frequently involve executive function, memory, and language. Motor difficulties associated with FTD may present with parkinsonian symptoms or motor neuron disease, for which riluzole is indicated as therapy. Compared to idiopathic Parkinson's disease, FTD-related atypical parkinsonism is generally not responsive to dopamine replacement therapies, but a small percentage of patients may experience improvement with a trial of carbidopa-levodopa. Physical and occupational therapy remain an important corner stone of motor symptom management in FTD. Speech therapy may also help patients manage symptoms associated with aphasia, apraxia, and dysarthria. Recent advances in the understanding of FTLD pathophysiology and genetics have led to development of potentially disease-modifying therapies as well as symptomatic therapies aimed at ameliorating social and behavioral deficits.

[Language deficits in major forms of dementia and primary progressive aphasias: an update according to new diagnostic criteria]

In this review, we report current data on spoken and written language disorders in the most frequent dementia syndromes, namely Alzheimer' disease, vascular cognitive impairment and dementia with Lewy bodies. Language deficits are also the core features of three variants of primary progressive aphasia, namely the nonfluent/agrammatic, semantic and logopenic variants. This review reveals that, like other cognitive functions, language is highly vulnerable to neurodegenerative diseases. For some, language deficits result from impairment in linguistic processes per se, while for others, they are the direct consequence of impairments affecting working memory and executive functions. Language deficits in Alzheimer's disease and in nonfluent/agrammatic and semantic variants of primary progressive aphasia are well documented. By contrast, those about vascular cognitive impairment and dementia with Lewy bodies remain scarce and limited to large cognitive domains. The identification of logopenic variant of primary progressive aphasia is very recent, and more research is needed to complete the clinical description and identification of the functional origin of the disorders. Finally, knowledge on the impairment of written language in neurodegenerative diseases is less well documented than those on spoken language deficits. Other studies are therefore needed to improve the description of linguistic profiles and to provide additional elements to help in the differential diagnosis.

Frontal white matter tracts sustaining speech production in primary progressive aphasia

In primary progressive aphasia (PPA), speech and language difficulties are caused by neurodegeneration of specific brain networks. In the nonfluent/agrammatic variant (nfvPPA), motor speech and grammatical deficits are associated with atrophy in a left fronto-insular-striatal network previously implicated in speech production. In vivo dissection of the crossing white matter (WM) tracts within this "speech production network" is complex and has rarely been performed in health or in PPA. We hypothesized that damage to these tracts would be specific to nfvPPA and would correlate with differential aspects of the patients' fluency abilities. We prospectively studied 25 PPA and 21 healthy individuals who underwent extensive cognitive testing and 3 T MRI. Using residual bootstrap Q-ball probabilistic tractography on high angular resolution diffusion-weighted imaging (HARDI), we reconstructed pathways connecting posterior inferior frontal, inferior premotor, insula, supplementary motor area (SMA) complex, striatum, and standard ventral and dorsal language pathways. We extracted tract-specific diffusion tensor imaging (DTI) metrics to assess changes across PPA variants and perform brain-behavioral correlations. Significant WM changes in the left intrafrontal and frontostriatal pathways were found in nfvPPA, but not in the semantic or logopenic variants. Correlations between tract-specific DTI metrics with cognitive scores confirmed the specific involvement of this anterior-dorsal network in fluency and suggested a preferential role of a posterior premotor-SMA pathway in motor speech. This study shows that left WM pathways connecting the speech production network are selectively damaged in nfvPPA and suggests that different tracts within this system are involved in subcomponents of fluency. These findings emphasize the emerging role of diffusion imaging in the differential diagnosis of neurodegenerative diseases.

Grammatical Impairments in PPA

BACKGROUND

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

AIMS

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

MAIN CONTRIBUTION

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

CONCLUSIONS

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

Brief intervention for agrammatism in Primary Progressive Nonfluent Aphasia: A case report

The non-fluent and agrammatic variant of Primary Progressive Aphasia (NFPPA) is characterized by reduced verbal production with deficits in building grammatically correct sentences, involving dysfunctions in syntactic and morphological levels of language. There are a growing number of studies about non-pharmacological alternatives focusing on the rehabilitation of functional aspects or specific cognitive impairments of each variant of PPA. This study reports a short-term treatment administered to a patient with NFPPA focusing on the production of sentences. The patient had significant reduction in verbal fluency, use of keywords, phrasal and grammatical simplifying as well as anomia. Using the method of errorless learning, six sessions were structured to stimulate the formation of sentences in the present and past with the cloze technique. The patient had improvement restricted to the strategy, with 100% accuracy on the trained phrases and generalization to untrained similar syntactic structure after training. These results persisted one month after the treatment.

Motor Speech Disorders Associated with Primary Progressive Aphasia

BACKGROUND

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

AIMS

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

MAIN CONTRIBUTION

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

CONCLUSION

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

Longitudinal Imaging and Deterioration in Word Comprehension in Primary Progressive Aphasia: Potential Clinical Significance

BACKGROUND

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

AIMS

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

METHODS AND PROCEDURES

Fifteen participants with PPA (5 logopenic variant PPA; 8 semantic variant PPA; 2 nonfluent/agrammatic variant PPA; mean age 67.8), underwent high resolution MRI and cognitive tests at least 9 months apart. The correlations between change in regional volumes and change in auditory word comprehension scores were investigated using Spearman test.

OUTCOMES & RESULTS

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

CONCLUSIONS

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

Beyond the temporal pole: limbic memory circuit in the semantic variant of primary progressive aphasia

Despite accruing evidence for relative preservation of episodic memory in the semantic variant of primary progressive aphasia (previously semantic dementia), the neural basis for this remains unclear, particularly in light of their well-established hippocampal involvement. We recently investigated the Papez network of memory structures across pathological subtypes of behavioural variant frontotemporal dementia and demonstrated severe degeneration of all relay nodes, with the anterior thalamus in particular emerging as crucial for intact episodic memory. The present study investigated the status of key components of Papez circuit (hippocampus, mammillary bodies, anterior thalamus, cingulate cortex) and anterior temporal cortex using volumetric and quantitative cell counting methods in pathologically-confirmed cases with semantic variant of primary progressive aphasia (n = 8; 61-83 years; three males), behavioural variant frontotemporal dementia with TDP pathology (n = 9; 53-82 years; six males) and healthy controls (n = 8, 50-86 years; four males). Behavioural variant frontotemporal dementia cases with TDP pathology were selected because of the association between the semantic variant of primary progressive aphasia and TDP pathology. Our findings revealed that the semantic variant of primary progressive aphasia and behavioural variant frontotemporal dementia show similar degrees of anterior thalamic atrophy. The mammillary bodies and hippocampal body and tail were preserved in the semantic variant of primary progressive aphasia but were significantly atrophic in behavioural variant frontotemporal dementia. Importantly, atrophy in the anterior thalamus and mild progressive atrophy in the body of the hippocampus emerged as the main memory circuit regions correlated with increasing dementia severity in the semantic variant of primary progressive aphasia. Quantitation of neuronal populations in the cingulate cortices confirmed the selective loss of anterior cingulate von Economo neurons in behavioural variant frontotemporal dementia. We also show that by end-stage these neurons selectively degenerate in the semantic variant of primary progressive aphasia with preservation of neurons in the posterior cingulate cortex. Overall, our findings demonstrate for the first time, severe atrophy, although not necessarily neuronal loss, across all relay nodes of Papez circuit with the exception of the mammillary bodies and hippocampal body and tail in the semantic variant of primary progressive aphasia. Despite the longer disease course in the semantic variant of primary progressive aphasia compared with behavioural variant frontotemporal dementia, we suggest here that the neural preservation of crucial memory relays (hippocampal→mammillary bodies and posterior cingulate→hippocampus) likely reflects the conservation of specific episodic memory components observed in most patients with semantic variant of primary progressive aphasia.

White matter disease correlates with lexical retrieval deficits in primary progressive aphasia

Objective: To relate fractional anisotropy (FA) changes associated with the semantic and logopenic variants of primary progressive aphasia (PPA) to measures of lexical retrieval.

Methods: We collected neuropsychological testing, volumetric magnetic resonance imaging, and diffusion-weighted imaging on semantic variant PPA (svPPA) (n = 11) and logopenic variant PPA (lvPPA) (n = 13) patients diagnosed using published criteria. We also acquired neuroimaging data on a group of demographically comparable healthy seniors (n = 34). FA was calculated and analyzed using a white matter (WM) tract-specific analysis approach. This approach utilizes anatomically guided data reduction to increase sensitivity and localizes results within canonically defined tracts. We used non-parametric, cluster-based statistical analysis to relate language performance to FA and determine regions of reduced FA in patients.

Results: We found widespread FA reductions in WM for both variants of PPA. FA was related to both confrontation naming and category naming fluency performance in left uncinate fasciculus and corpus callosum in svPPA and left superior and inferior longitudinal fasciculi in lvPPA.

Conclusion: SvPPA and lvPPA are associated with distinct disruptions of a large-scale network implicated in lexical retrieval, and the WM disease in each phenotype may contribute to language impairments including lexical retrieval.