Progressive Nonfluent Aphasia Patients Research Articles

Music appreciation phenotypes in patients with frontotemporal dementia: A pilot study.

ObjectivesFrontotemporal dementia (FTD) can present with changes in music appreciation. Research has suggested a relationship of altered music appreciation phenotypes with typical socio‐emotional changes. We aimed to determine the prevalence and severity of music appreciation phenotypes in FTD and study the relationship with emotion recognition capacities in order to examine whether they could serve as a proxy for changes in socio‐emotional functioning.Methods/DesignBased on reported musical changes in the literature, we developed an informant‐based questionnaire to assess musical changes and a music test to assess music emotion recognition. Social cognition was assessed with the Ekman 60 faces test in a subgroup of patients (n = 23). Relationships between measures were assessed with linear regressions.ResultsWe included 47 patients (44.7% female, mean age 65.0 ± 8.4, 31 behavioral variant FTD (bvFTD), 10 semantic dementia (SD), and six progressive nonfluent aphasia (PNFA)). Thirty‐six caregivers were included in the music emotion recognition test as controls. Altered music appreciation phenotypes were observed in 79% of the FTD patients. Musicophilia was present in a third of bvFTD patients, and only in up to 10% in language FTD variants. Changes in music appreciation were not associated with decreased music emotion recognition or visual emotion recognition. Compared to controls, bvFTD performed worse on the music emotion recognition task (p < 0.003), and no differences were found with SD (p = 0.06) and PNFA patients (p = 0.8).ConclusionsMusic appreciation phenotypes are highly prevalent in FTD patients. Future studies should further investigate the potential diagnostic value of changes in music processing.

Altered music processing phenotypes in patients with frontotemporal dementia

AbstractBackgroundFrontotemporal dementia (FTD) can present with changes in music appreciation. The aim of the present study was to determine the prevalence and nature of music appreciation phenotypes among FTD syndromes in a memory clinic population.MethodForty‐seven FTD patients (44.7% female, mean age 65.0±8.4, 31 behavioral variant FTD (bvFTD), 10 semantic dementia (SD), 6 progressive nonfluent aphasia (PNFA)) who consecutively visited our memory clinic were included in this study. Forty‐six caregivers (54.3% female, mean age 61.8±9.2) were included as a control group. Based on reported musical changes in the literature, we developed an informant‐based questionnaire by extending a previously used questionnaire (Fletcher et al., 2015). Music‐emotion recognition was assessed with a live music test in which both participants and caregivers were played 9 guitar chords, and rated if these were major, minor or dissonant (i.e. happy, sad or disharmonic). Visual emotion recognition was examined with the Ekman 60 faces test in a subgroup of patients (n= 23). Non‐parametric tests were used for group comparisons.ResultMusic appreciation phenotypes were observed in 79% of the FTD patients. Musicophilia was most often present (in 12/47 patients, 26%), followed by music anhedonia (23%), change of music taste (21%), increased singing (21%), sound‐aversion (19%), music‐aversion (13%), music agnosia (9%) and increased dancing (5%). Musicophilia was present in a third of bvFTD patients, but only in 10% of the semantic dementia and none of PNFA patients. The other reported music changes were more evenly distributed. The presence of music changes was not associated with lower performance on the music emotion recognition task (p = 0.62) or visual emotion recognition task (p = 0.87). However, compared to controls, bvFTD performed worse on the music emotion recognition task (p&lt; .003), SD performed worse at trend level (p = .06) and no differences were found with PNFA (p = .8) patients (figure 1).ConclusionMusic appreciation phenotypes are highly prevalent in the FTD population, consist of a variety of symptoms, differ between syndromes and do not do not correlate with emotion recognizing capacities. Furthermore, compared to controls, bvFTD performed worse on a music emotion recognition test.

Correlations between clinical characteristics and neuroimaging in Chinese patients with subtypes of frontotemporal lobe degeneration.

The aim of the study was to obtain an overview of the clinical and neuroimaging features of Chinese patients with subtypes of frontotemporal lobe degeneration (FTLD).We evaluated the demographic features, clinical presentation, and lobe atrophy depicted by magnetic resonance imaging (MRI) in 133 patients with FTLD. Two positron emission tomography (PET) scans were performed at baseline: [11C]Pittsburgh compound B PET to assess amyloid-β plaque load and [18F]fluorodeoxyglucose (FDG) PET to assess glucose metabolism.The behavioral variant of FTD (bvFTD) was the most common subtype (67.7%) of FTLD. The percentages of progressive nonfluent aphasia (PNFA) and semantic dementia (SD) were similar. Cerebral lobe atrophy was seen in 87.7% of the cases. The Activities of Daily Living scale, Mini-Mental State Examination, and Montreal Cognitive Assessment scores were significantly correlated with the degree of overall atrophy. The severity of abnormal behavior was correlated with right anterior and right posterior temporal atrophy scores. The overall atrophy scores and atrophy score in the left temporal region were related to cognitive outcomes and Activities of Daily Living scores. Most of the bvFTD patients presented symmetric/asymmetric hypometabolism in the bilateral temporal cortex, frontal cortex, anterior cingulate cortex, insula, and caudate nucleus. All the PNFA patients presented left dominant hypometabolism in the frontal cortex. All the SD patients presented left dominant hypometabolism in the anterior temporal cortex.FTLD is not rare in cognitive clinics, and the ratios of subtypes in Chinese patients are similar to other ethnic groups. Overall atrophy scores, determined by MRI, were related to the severity of cognitive dysfunction and deficits in Activities of Daily Living. Patterns of hypometabolism, determined by [18F]FDG PET, were more specific to subtypes of FTLD and may help provide differential diagnoses of variants of FTLD.

Clinical characteristics of parkinsonism in frontotemporal dementia according to subtypes

BackgroundWe investigated the prevalence of parkinsonism in frontotemporal dementia (FTD) subtypes and the cognitive and behavioral differences between FTD with and without parkinsonism in a well-structured, prospective cohort. MethodsOne hundred and ninety-one FTD patients were enrolled and all patients underwent comprehensive neurological evaluations, neuropsychological tests, and the Unified Parkinson's Disease Rating Scale. ResultsThe prevalence of parkinsonism was 38.7% (74 patients), and included 33 (46.5%) behavioral variant FTD (bvFTD), 16 (24.2%) semantic dementia (SD), 19 (45.2%) progressive nonfluent aphasia (PNFA), and 6 (50%) FTD associated with motor neuron disease (FTD-MND). SD patients with parkinsonism had higher CDR sum of boxes scores (9.7±4.5 vs 6.2±4.5, p=0.024), frontal behavioral inventory total score (33.7±20.5 vs 24.3±14.5, p=0.045), and executive function score of frontal executive dysfunction, disinhibition, and apathy (28.9±13.7 vs 19.2±12.9, p=0.021) than those without parkinsonism. Seoul Instrumental Activities of Daily Living score (bvFTD: 23.5±11.7 vs 17.3±11.3, p=0.031, SD: 23.1±11.1 vs 11.3±9.3, p=0.005) was higher for bvFTD and SD with parkinsonism than for those without parkinsonism. ConclusionsParkinsonism is found to be more common in patients with bvFTD, PNFA, and FTD-MND patients than those with SD. Behavioral disturbances were more prominent in SD with parkinsonism than without. Additional studies are needed to determine the pathomechanism and optimal treatment of parkinsonism in different FTD subtypes.

Syntactic comprehension deficits across the FTD-ALS continuum

To establish the frequency, severity, relationship to bulbar symptoms, and neural correlates of syntactic comprehension deficits across the frontotemporal dementia–amyotrophic lateral sclerosis (FTD-ALS) disease spectrum. In total, 85 participants were included in the study; 20 amyotrophic lateral sclerosis (ALS), 15 FTD-ALS, 27 progressive nonfluent aphasia (PNFA), and 23 controls. Syntactic comprehension was evaluated in ALS, FTD-ALS, PNFA, and controls using the Test for Reception of Grammar. Voxel-based morphometry examined neuroanatomical correlates of performance. Syntactic comprehension deficits were detected in 25% of ALS (p = 0.011), 92.9% of FTD-ALS (p < 0.001), and 81.5% of PNFA (p < 0.001) patients. FTD-ALS was disproportionately impaired compared to PNFA. Impaired Test for Reception of Grammar performance was frequent in ALS with early bulbar involvement but did not correlate with bulbar impairment overall. Left peri-insular atrophy correlated with syntactic comprehension deficits. Syntactic comprehension deficits are frequent in FTD-ALS, more severe than in PNFA, and related to left peri-insular atrophy. A significant minority of ALS patients are impaired, but the relationship between bulbar symptoms and syntactic impairment is not understood.

Clinical and Neuropsychological Comparisons of Early-Onset Versus Late-Onset Frontotemporal Dementia: A CREDOS-FTD Study.

Cognitive performance changes with chronological aging. Previous studies investigating clinical heterogeneity in frontotemporal dementia (FTD) according to the age of symptom onset did not consider the effect of chronological aging on cognition. We compared cognitive and behavioral symptoms in patients with early-onset (EO) and late-onset (LO) FTD with consideration of chronological aging effect. A total of 166 FTD patients were enrolled consecutively from multi-center memory clinics using a nationwide FTD register. To control for the effects of chronological aging on neuropsychological scores, seven hundred and two subjects with normal cognition were also enrolled and regression models were set up. Neuropsychological scores that were detrended with the regression models and the behavioral symptoms of the EO-FTD and LO-FTD groups were compared. Subgroup analyses were performed for three main subtypes of FTD, behavioral variant frontotemporal dementia (bvFTD), semantic dementia (SD), and progressive non-fluent aphasia (PNFA). Among 166 FTD patients, there were 76 bvFTD, 57 SD, and 33 PNFA patients who met new diagnostic criteria for bvFTD or primary progressive aphasia, respectively. LO-FTD (48.2%) was more common than previously thought and the proportions of EO and LO groups differed across FTD subtypes. EO-FTD patients had lower memory and frontal/executive scores and more prominent frontal/behavioral symptoms than LO-FTD patients. Our study suggested that FTD could be heterogeneous with respect the age of symptom onset. After controlling for the effects of chronological aging, EO-FTD patients exhibited more profound memory and frontal/executive dysfunction and more behavioral symptoms than LO-FTD patients.

Shape Analysis of the Corpus Callosum in Alzheimer's Disease and Frontotemporal Lobar Degeneration Subtypes

Morphology of the corpus callosum is a useful biomarker of neuronal loss, as different patterns of cortical atrophy help to distinguish between dementias such as Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). We used a sophisticated morphometric analysis of the corpus callosum in FTLD subtypes including frontotemporal dementia (FTD), semantic dementia (SD), and progressive non-fluent aphasia (PNFA), and compared them to AD patients and 27 matched controls. FTLD patient subgroups diverged in their callosal morphology profiles, with FTD patients showing marked widespread differences, PNFA patients with differences largely in the anterior half of the callosum, and SD patients differences in a small segment of the genu. AD patients showed differences in predominantly posterior callosal regions. This study is consistent with our previous findings showing significant cortical and subcortical regional atrophy across FTLD subtypes, and suggests that callosal atrophy patterns differentiate AD from FTLD, and FTLD subtypes.

The Impact of Dementia Severity on Caregiver Burden in Frontotemporal Dementia and Alzheimer Disease

Caregiver burden is greater in frontotemporal dementia (FTD) than in Alzheimer disease (AD). However, little is known of the impact of the 3 main clinical variants of FTD- behavioral-variant frontotemporal dementia (bvFTD), semantic dementia (SemDem), and progressive nonfluent aphasia (PNFA)-or the role of disease severity in caregiver burden. The Zarit Burden Inventory was used to measure caregiver burden of bvFTD (n=17), SemDem (n=20), PNFA (n=20), and AD (n=19) patients. Symptom duration, caregiver age, and relationship type were matched across groups. Moreover, a number of caregiver (mood, social network) and patient variables (functional disability, behavioral changes, relationship with caregiver, and dementia stage) were addressed to investigate their impact on caregiver burden. Caregivers of bvFTD patients reported the highest burden, whereas SemDem and PNFA caregivers reported burden similar to AD. A regression analysis revealed that caregiver burden in FTD, regardless of subtype, was explained by a model combining disease staging, relationship changes, and caregiver depression. Burden increased with disease severity in FTD. This study is the first to show that caregivers of SemDem, PNFA, and AD patients show similar burden, while confirming that bvFTD caregivers show higher burden than AD caregivers. More importantly, this study demonstrates that burden worsens with disease progression in FTD.

Perfusion SPECT studies with mapping of Brodmann areas in differentiating Alzheimer’s disease from frontotemporal degeneration syndromes

The aim of this study was to evaluate the contribution of brain perfusion single-photon emission computed tomography (SPECT) studies with mapping of Brodmann areas (BAs) in the differential diagnosis between Alzheimer's disease (AD) and frontotemporal degeneration (FTLD) syndromes. Thirty-nine patients with AD and 73 patients with FTLD syndromes [behavioural variant FTLD (bvFTLD); language variant FTLD (lvFTLD), including semantic dementia (SD) and progressive nonfluent aphasia (PNFA); and corticobasal degeneration (CBD)/progressive supranuclear palsy (PSP) syndromes] underwent brain perfusion SPECT. The NeuroGam software was used for the semiquantitative evaluation of perfusion in BAs of the left (L) and right (R) hemispheres. Compared with those in AD patients, BAs with statistically significant hypoperfusion were found in the prefrontal, orbitofrontal and cingulated cortices and Broca's areas of FTLD and bvFTLD patients; in the temporal and prefrontal cortices and Broca's areas of lvFTLD patients; in the left temporal gyrus of SD patients; in premotor and supplementary motor, prefrontal, orbitofrontal, temporal and anterior cingulated cortices and Broca's areas of PNFA patients; and in the prefrontal, temporal, posterior cingulated and primary and secondary visual cortices of CBD/PSP patients. BA 46R could differentiate AD patients from FTLD and bvFTLD patients; 21L and 25L were found to be independent predictors for lvFTLD in comparison with AD, and 25R, 21L and 23R could differentiate AD patients from PNFA, SD and CBD/PSP patients, respectively. Brain perfusion SPECT with BA mapping in AD and FTLD patients could improve the definition of brain areas that are specifically implicated in these disorders, resulting in a more accurate differential diagnosis.

Are you really angry? The effect of intensity on facial emotion recognition in frontotemporal dementia

Frontotemporal dementia (FTD) is a neurodegenerative brain disorder that affects the frontal and temporal lobes predominantly. Impaired emotion recognition has been reported in two FTD subtypes: behavioral-variant FTD (bvFTD) and semantic dementia (SD), but has not been investigated in the third subtype: progressive nonfluent aphasia (PNFA). Methods: Recognition of six basic facial emotions (anger, disgust, fear, sadness, surprise, and happiness) was investigated in 41 FTD patients (bvFTD = 16; SD = 12; PNFA = 13) and 37 age- and education-matched controls, using two tests. In one task, intensity of emotional expression was increased to identify cognitive components contributing to emotion recognition performance. Results: All patient groups demonstrated impaired overall facial emotion recognition compared to controls. Performance, however, improved with increased emotion intensity in bvFTD and PNFA groups, the effect of intensity on emotion recognition being particularly pronounced for negative emotions. In contrast, increased intensity of facial emotion did not change performance in SD. Conclusions: Patients with SD demonstrate a primary emotion processing impairment, whereas PNFA and bvFTD patients' emotional disturbance is in part mediated by attentional deficits. These findings indicate that a subset of FTD patients may benefit from enhanced emotional intensity that will facilitate facial emotion recognition.

Screening for Cognitive Dysfunction in Corticobasal Syndrome: Utility of Addenbrooke’s Cognitive Examination

Introduction: The motor features of corticobasal syndrome (CBS) are well recognized but the fact that many, if not all, affected patients develop cognitive impairment is still underrecognized. The dementia of CBS overlaps most with a language variant of frontotemporal dementia: progressive nonfluent aphasia (PNFA). The aim of this study was to determine the usefulness of Addenbrooke’s Cognitive Examination-Revised (ACE-R) in the evaluation of CBS and to document similarities and differences between CBS and PNFA. Materials and Methods: Patients with well-defined CBS or PNFA from two tertiary referral centers were selected along with matched controls. Results: Twenty-one patients with CBS, 23 patients with PNFA and 47 age- and education- matched controls were included. Both CBS and PNFA groups showed substantial impairment on the ACE-R (f = 17.3–80.2, p < 0.001) and were significantly impaired in all domains (p < 0.001). The only significant difference between CBS and PNFA was in the visuospatial domain (p < 0.009), being worse in CBS. Using a cutoff of 88/89 out of 100, 90% of CBS and 82.6% of PNFA patients were impaired. At this cutoff of 88/89, ACE-R in CBS had sensitivity and specificity values of 91 and 98%, respectively.

Glucose metabolism in progressive non-fluent aphasia patients with versus without parkinsonism

Conclusions: FUS protein accumulation is characteristic in a group of FTLDs with ubiquitin-positive pathology. The clinical features are heterogeneous although the most common association is with bvFTD. Clinical and pathological evidence of MND may be found in cases previously diagnosed as NIFID. FUS-positive inclusions in both cerebral cortex and motor neurons in NIFID and aFTLD-U extend the spectrum of diseases with frontotemporal degeneration and involvement of the motor system.

Frontal lobe damage impairs process and content in semantic memory: Evidence from category-specific effects in progressive non-fluent aphasia

Portions of left inferior frontal cortex have been linked to semantic memory both in terms of the content of conceptual representation (e.g., motor aspects in an embodied semantics framework) and the cognitive processes used to access these representations (e.g., response selection). Progressive non-fluent aphasia (PNFA) is a neurodegenerative condition characterized by progressive atrophy of left inferior frontal cortex. PNFA can, therefore, provide a lesion model for examining the impact of frontal lobe damage on semantic processing and content. In the current study we examined picture naming in a cohort of PNFA patients across a variety of semantic categories. An embodied approach to semantic memory holds that sensorimotor features such as self-initiated action may assume differential importance for the representation of manufactured artifacts (e.g., naming hand tools). Embodiment theories might therefore predict that patients with frontal damage would be differentially impaired on manufactured artifacts relative to natural kinds, and this prediction was borne out. We also examined patterns of naming errors across a wide range of semantic categories and found that naming error distributions were heterogeneous. Although PNFA patients performed worse overall on naming manufactured artifacts, there was no reliable relationship between anomia and manipulability across semantic categories. These results add to a growing body of research arguing against a purely sensorimotor account of semantic memory, suggesting instead a more nuanced balance of process and content in how the brain represents conceptual knowledge.

Longitudinal patterns of semantic and episodic memory in frontotemporal lobar degeneration and Alzheimer's disease.

The longitudinal assessment of episodic and semantic memory was obtained from 236 patients diagnosed with Alzheimer's disease (AD, n = 128) and with frontotemporal lobar degeneration (FTLD, n = 108), including patients with a social comportment/dysexecutive (SOC/EXEC) disorder, progressive nonfluent aphasia (PNFA), semantic dementia (SemD), and corticobasal syndrome (CBS). At the initial assessment, AD patients obtained a lower score on the delayed free recall test than other patients. Longitudinal analyses for delayed free recall found converging performance, with all patients reaching the same level of impairment as AD patients. On the initial evaluation for delayed recognition, AD patients also obtained lower scores than other groups. Longitudinal analyses for delayed recognition test performance found that AD patients consistently produced lower scores than other groups and no convergence between AD and other dementia groups was seen. For semantic memory, there were no initial between-group differences. However, longitudinal analyses for semantic memory revealed group differences over illness duration, with worse performance for SemD versus AD, PNFA, SOC/EXEC, and CBS patients. These data suggest the presence of specific longitudinal patterns of impairment for episodic and semantic memory in AD and FTLD patients suggesting that all forms of dementia do not necessarily converge into a single phenotype.

Sentence comprehension and voxel-based morphometry in progressive nonfluent aphasia, semantic dementia, and nonaphasic frontotemporal dementia

To investigate the basis for impaired sentence comprehension in patients with frontotemporal dementia (FTD) we assessed grammatical comprehension and verbal working memory in 88 patients with three distinct presentations: progressive nonfluent aphasia (PNFA), semantic dementia (SD), and nonaphasic patients with a disorder of social comportment and executive processing (SOC/EXEC). We related sentence comprehension and working memory performance to regional cortical volume in a subgroup of 29 patients with structural MRI scans using voxel-based morphometry. PNFA patients exhibited the greatest difficulty with sentence comprehension and were especially impaired with grammatically complex sentences, which correlated with atrophy in left inferior frontal cortex. Working memory performance in these same patients correlated with a proximal but distinct left inferior frontal region. SD patients’ sentence comprehension scores correlated with left inferolateral temporal lobe damage, which we hypothesize reflects impairments in lexical processing. We did not observe any consistent relationship between cortical atrophy and sentence comprehension impairment in SOC/EXEC patients, suggesting the deficits in this subgroup may be due to more variable declines in executive resources.

Repeat and Point: Differentiating semantic dementia from progressive non-fluent aphasia

To determine whether a new, simple, quick measure, the Repeat and Point test, reliably differentiates between semantic dementia (SD) and progressive non-fluent aphasia (PNFA).Fifteen patients with SD, six patients with PNFA and 18 healthy controls were administered the Repeat and Point test. Participants were required to repeat 10 multi-syllabic concrete nouns and, following each repetition, to point to the word's pictorial referent amongst an array of six semantically and perceptually similar foils.Patients with SD were consistently impaired relative to PNFA patients and controls on the comprehension (pointing) component of the task, whereas patients with PNFA showed no significant deficit on pointing but were impaired at the production (repeating) component. Discriminant function analysis confirmed perfect classification of the individual patients into their respective groups: criteria involving a ratio of the two scores are provided.The Repeat and Point test is particularly appropriate for routine use in a clinical context: it is quick and easy to administer and score; it reliably discriminated between the two patient groups, SD and PNFA; and it offers a simple rule of thumb, i.e., the Repeat-to-Point ratio, to aid in the diagnosis of these two language variants of frontotemporal dementia (FTD).

Language Processing in Frontotemporal Dementia: A Brief Review

Frontotemporal dementia (FTD) is a neurodegenerative condition that presents with a number of distinct behavioral phenotypes. Here we review languageprocessing deficits in three subgroups of FTD patients: progressive nonfluent aphasia (PNFA), semantic dementia (SD), and nonaphasic FTD patients with a disorder of social and executive functioning (SOC/EXEC). These three clinical subgroups have contrasting patterns of regional cortical atrophy that can be linked to their language impairments. PNFA patients’ disease includes left ventral inferior frontal cortex, resulting in impaired grammatical processing. SD patients demonstrate a profound impairment for semantic knowledge related to atrophy of the left temporal lobe. SOC/EXEC patients’ frontal atrophy tends to be more right lateralized and is associated with declines in executive functioning. SOC/EXEC patients’ limited executive resources impact language processing in a variety of ways, including slowed grammatical processing and impaired narrative discourse. FTD patients therefore provide converging evidence regarding dissociable components of language processing and their neuroanatomical bases. Understanding single words requires extensive perceptual, lexical, and semantic processing (Price 1998). Comprehending a sentence poses additional requirements of knowing the rules governing relationships between words and applying these words during processing (Friederici 2002), and engaging in a conversation also depends on the ability to plan a narrative and exchange information in an organized and interactive manner with others. These processes are subserved by a distributed network of brain regions that have been elucidated largely through studies of stroke patients and functional neuroimaging in healthy adults. More recently, converging evidence regarding the neuroanatomical bases for language processing comes from patients with focal patterns of cortical atrophy, such as those observed in frontotemporal dementia (FTD). 1 Frontotemporal dementia encompasses a spectrum of syndromes of varying etiologies that result in relatively focal damage to the frontal and temporal lobes. It occurs primarily in older adults, although its average age of onset is earlier than that of Alzheimer’s disease (Haase 1977; Brun and Gustafson

Screening for Frontotemporal Dementias and Alzheimer’s Disease with the Philadelphia Brief Assessment of Cognition: A Preliminary Analysis

Background: A neuropsychological screening instrument sensitive to neuropsychological deficits associated with Alzheimer’s disease (AD) and patients with frontotemporal dementia (FTD) would be valuable for diagnostic evaluation. Methods: The Philadelphia Brief Assessment of Cognition (PBAC) assesses working memory/executive control, language, visuospatial operations, verbal/visual episodic memory, and behavior/social comportment and can be administered and scored in 15–20 min. Participants included 149 patients with AD and four groups of FTD patients – i.e., patients with a decline in social comportment, personality, and executive functioning (SOC/EXEC), semantic dementia (SemD), progressive nonfluent aphasia (PNFA), and corticobasal syndrome (CBS). Results: The total PBAC score correlated with the Mini-Mental State Examination. Between-group analysis of PBAC subscales and the results of logistic regression analyses produced substantial between-group differences, emphasizing the sensitivity of the test to differentiate dementia subtypes. AD patients were impaired on tests of episodic memory, SOC/EXEC patients were impaired on a measure of social comportment/behavioral disturbance, PNFA patients obtained low scores on tests of working memory/executive control, SemD patients obtained lower scores on language-mediated measures, and CBS patients were impaired on visuospatial/visual memory tests. Conclusion: These data support the usefulness of the PBAC as a relatively brief screening test of overall dementia severity across a wide range of dementia patients.

Syntactic and thematic components of sentence processing in progressive nonfluent aphasia and nonaphasic frontotemporal dementia

We used an online word-monitoring paradigm to examine sentence processing in healthy seniors and frontotemporal dementia patients with progressive nonfluent aphasia (PNFA) or a nonaphasic disorder of social and executive functioning (SOC/EXEC). Healthy seniors were sensitive to morphosyntactic, major grammatical subcategory, and selection restriction violations in a sentence. PNFA patients were insensitive to grammatical errors, but showed reasonable sensitivity to thematic matrix violations, consistent with a differential grammatical processing impairment. By contrast, SOC/EXEC patients showed partial sensitivity to grammatical errors but were insensitive to thematic violations. These findings support a dissociation between grammatical and thematic components of sentence processing. Specifically, they are consistent with a grammatical processing deficit in PNFA patients, and impairment in the formation of a coherent thematic matrix in SOC/EXEC patients.

Lexical acquisition in progressive aphasia and frontotemporal dementia

We investigated the characteristics of language difficulty in frontotemporal dementia (FTD) by exposing these patients to a new verb in a naturalistic manner and then assessing acquisition of the grammatical, semantic, and thematic matrix information associated with the new word. We found that FTD patients have difficulty relative to healthy seniors in their acquisition of the new verb, but that progressive nonfluent aphasia (PNFA), semantic dementia (SD), and social/dysexecutive variant (SOC/EXEC) subgroups of FTD demonstrate relatively distinct impairment profiles. Specifically, PNFA patients showed relative difficulty assigning the new verb to its correct grammatical form class, reflecting compromised processing of the associated grammatical information. SD patients were impaired at associating the new word with its pictorial representation, suggesting impaired processing of the new verb's semantic attributes. SOC/EXEC patients showed their greatest difficulty judging violations of the new word's associated thematic roles, implying that limited executive resources underlie in part the difficulty in integrating grammatical and semantic information into a coherent thematic matrix. Similar impairment profiles were seen during a follow-up session one week after the initial evaluation. These deficits in lexical acquisition reflect the breakdown of a language-processing system that consists of highly interactive but partially dissociable grammatical, semantic, and resource-based components, leading to relatively distinct language-processing deficits in each subgroup of patients with FTD.