The impact of phonological short-term memory impairment on verbal repetition in the logopenic variant of primary progressive aphasia

The logopenic variant of primary progressive aphasia (lvPPA) is characterized mainly by anomia, production of phonological errors, and impairment in repetition of sentences. The functional origin of these language impairments is mainly attributed to the breakdown of phonological short-term memory. The present study examined the effects of phonological short-term memory impairment on language processing in lvPPA. In two studies, 11 participants with lvPPA and 11 healthy control participants were presented with repetition tasks in which the type and length of stimuli and the mode of administration were manipulated. Study 1 aimed to examine the influence of length and lexicality (words vs. pseudowords) on immediate and delayed repetition, whereas Study 2 aimed to examine the influence of length, syntactic complexity (nominalized vs. pronominalized sentences), and serial position on immediate sentence repetition. Study 1 showed that participants' performance with lvPPA was impaired only on immediate repetition of five-syllable pseudowords and on delayed repetition of words and pseudowords. Study 2 showed that participants' performance with lvPPA was impaired in the repetition of nominalized sentences where a recency effect was observed. Repetition of pronominalized sentences was also impaired in the lvPPA group. This study provides additional support for arguments regarding phonological short-term memory as a cause of language impairment in lvPPA. Clinically, the results of the study suggest that instruments for assessing repetition ability in lvPPA should include not only lists of short or long nominalized sentences, but also delayed repetition of words and pseudowords and pronominalized sentences.

Clinical and cortical trajectories in non-fluent primary progressive aphasia and Alzheimer's disease: A role for emotion processing

OBJECTIVES

To examine the clinical trajectories and neural correlates of cognitive and emotion processing changes in the non-fluent/agrammatic (nfvPPA) and the logopenic (lvPPA) variants of primary progressive aphasia (PPA).

DESIGN

Observational case-control longitudinal cohort study.

SETTING

Research clinic of frontotemporal dementia.

PARTICIPANTS

This study recruited 29 non-semantic PPA patients (15 nfvPPA and 14 lvPPA) and compared them with 15 Alzheimer's disease (AD) patients and 14 healthy controls.

MEASUREMENTS

Participants completed an annual assessment (median = 2 years; range = 1-5 years) of general cognition, emotion processing and structural MRI. Linear mixed effects models investigated clinical and imaging trajectories between groups.

RESULTS

Over time, lvPPA showed the greatest cognitive deterioration. In contrast, nfvPPA showed significant decline in emotion recognition, whereas AD showed preserved emotion recognition, even with disease progression. Importantly, lvPPA also developed emotion processing impairments, with disease progression. Both nfvPPA and lvPPA showed continuing cortical atrophy in hallmark language-processing regions associated with these syndromes, together with progressive involvement of the right hemisphere regions, mirroring left hemisphere atrophy patterns at presentation. Decline in emotion processing was associated with bilateral frontal atrophy in nfvPPA and right temporal atrophy in lvPPA.

CONCLUSIONS

Our results show divergent clinical courses in nfvPPA and lvPPA, with rapid cognitive and neural deterioration in lvPPA and emotion processing decline in both groups and support the concurrent assessment of cognition and emotion processing in the clinic to inform diagnosis and monitoring in the non-semantic variants of PPA.

A - 66 Non-Fluent/Agrammatic Variant of Primary Progressive Aphasia (Nappa) in a Bilingual Chinese Speaker: a Single-Case Study

OBJECTIVE

The non-fluent/agrammatic variant of primary progressive aphasia (naPPA) is a neurodegenerative syndrome associated with agrammatism in language production and effortful speech (Gorno-Tempini et al., 2011). There is limited literature on PPA in non-English speakers and few clinical cases of bilingual naPPA have been described (Tee et al., 2022; Zanini et al., 2011). Characteristics of symptoms in orthographic languages, such as Chinese, are not well understood (Ting et al., 2017). This case describes the assessment of naPPA in a bilingual Mandarin Chinese speaker.

METHOD

A 66-year-old Asian male with 16 years of education complained of worsening aphasia in both languages over two years with initial preferential sparing of Chinese. A comprehensive neuropsychological battery was administered mostly in Chinese with select subtests in English. Language functioning was assessed with the Bilingual Aphasia Screening Test (Paradis & Libben, 1987).

RESULTS

Agrammatism and apraxia of speech was present in both languages. Single-word comprehension and object knowledge was preserved, while comprehension of complex commands was impaired. Lexical discrimination of real and nonsense words was preserved. Delayed memory was impaired with relative improvement upon recognition. Attention, processing speed, visuospatial skills, and motor functioning were preserved. Mood was euthymic.

CONCLUSIONS

This case revealed deficits in both languages with slower decline of the dominant language, suggesting that the less proficient language in bilinguals is more vulnerable to degeneration in naPPA.

B - 83 A Case Study of Suspected Progressive Non-Fluent Aphasia in an Older Adult with a Prior History of Seizures

OBJECTIVE

Progressive non-fluent aphasia (PNFA) is a neurodegenerative disorder characterized by agrammatism and apraxia of speech. Other features include impaired comprehension of syntactically complex structures, intact object knowledge, and spared single-word comprehension. Given the complexity of primary progressive aphasia (PPA) syndromes, neuropsychologists can play a vital role in differential diagnosis, particularly when there are comorbid medical factors.

METHOD

This case study presents on a 74-year-old female with progressive language and cognitive impairment over the past 8 years whose care was jointly managed in specialty neurology clinics (e.g., Epilepsy and Memory Disorders) at a university medical center. She had a history of generalized convulsive seizures but with none occurring in several years. She was weaned off phenobarbital over the course of a few months to help rule out any adverse effects on functioning but her deficits persisted. Follow-up MRI showed mild-to-moderate diffuse atrophy. Her cognitive neurologist raised concerns for PPA which prompted the neuropsychological evaluation 3-4 months later.

RESULTS

Testing showed prominent impairments in fluency, naming, repetition, oral reading, and comprehension for grammatically complex questions while semantic knowledge for objects was preserved. Conversational language was halting, effortful, dysfluent, and anomic. Broader cognitive deficits were also observed during testing which was suggestive of more generalized cerebral dysfunction.

CONCLUSIONS

The patient's profile was highly concerning for PNFA. Further work-up at the institution's Frontotemporal Dementia Clinic along with an FDG-PET scan were recommended to help further clarify her profile. Overall, this case highlights the utility of neuropsychology in the differential diagnosis of complex neurodegenerative disorders with comorbid medical factors.

A - 87 A Neuropsychological Case Study of Primary Progressive Apraxia of Speech Versus Agrammatic Primary Progressive Aphasia

OBJECTIVE

Primary progressive apraxia of speech (PPAOS) is a lesser-known neurodegenerative disorder characterized by progressive speech production loss, affecting word articulation. Apraxic speech commonly occurs in primary progressive aphasias (PPAs) and as a result, is often misdiagnosed as agrammatic PPA (aPPA). The current case highlights the importance of neuropsychological evaluations and behavioral observations in delineating PPAOS from aPPA.

METHOD

The patient is a 71-year-old right-handed White female who presented with a 2-year history of language difficulties beginning with a lisp and progressing to an inability to produce words. MRI of the brain showed moderate white matter disease.

RESULTS

Her neurocognitive profile was notable for primary deficits in expressive language, including oral/written production, verbal fluency, and repetition. Milder deficits were observed in aspects of executive functioning. Observed spontaneous speech was notable for impaired and effortful articulation with syllabically segmented prosodic speech patterns, some distortions and prosody alterations, and slow rate. All other cognitive domains were intact.

CONCLUSIONS

Patients with PPAOS and aPPA typically score in the impaired range on tests that depend on rate and accuracy of speech. Apraxia was her most salient feature reported and observed on testing. We did not find learning and memory difficulties, which are more common in aPPA. Moreover, she had trial-and-error articulatory attempts, groping, and distorted substitutions, which are more commonly seen in PPAOS. Her speech was also devoid of grammatical errors which is another distinguishing feature. While subtle and confounded by her alcohol use and orthopedic injuries, her profile altogether appeared most consistent with PPAOS.

Comprehension of acoustically degraded speech in Alzheimer's disease and primary progressive aphasia

Successful communication in daily life depends on accurate decoding of speech signals that are acoustically degraded by challenging listening conditions. This process presents the brain with a demanding computational task that is vulnerable to neurodegenerative pathologies. However, despite recent intense interest in the link between hearing impairment and dementia, comprehension of acoustically degraded speech in these diseases has been little studied. Here we addressed this issue in a cohort of 19 patients with typical Alzheimer's disease and 30 patients representing the three canonical syndromes of primary progressive aphasia (non-fluent/agrammatic variant primary progressive aphasia; semantic variant primary progressive aphasia; logopenic variant primary progressive aphasia), compared to 25 healthy age-matched controls. As a paradigm for the acoustically degraded speech signals of daily life, we used noise-vocoding: synthetic division of the speech signal into frequency channels constituted from amplitude-modulated white noise, such that fewer channels convey less spectrotemporal detail thereby reducing intelligibility. We investigated the impact of noise-vocoding on recognition of spoken three-digit numbers and used psychometric modelling to ascertain the threshold number of noise-vocoding channels required for 50% intelligibility by each participant. Associations of noise-vocoded speech intelligibility threshold with general demographic, clinical and neuropsychological characteristics and regional grey matter volume (defined by voxel-based morphometry of patients' brain images) were also assessed. Mean noise-vocoded speech intelligibility threshold was significantly higher in all patient groups than healthy controls, and significantly higher in Alzheimer's disease and logopenic variant primary progressive aphasia than semantic variant primary progressive aphasia (all P < 0.05). In a receiver operating characteristic analysis, vocoded intelligibility threshold discriminated Alzheimer's disease, non-fluent variant and logopenic variant primary progressive aphasia patients very well from healthy controls. Further, this central hearing measure correlated with overall disease severity but not with peripheral hearing or clear speech perception. Neuroanatomically, after correcting for multiple voxel-wise comparisons in predefined regions of interest, impaired noise-vocoded speech comprehension across syndromes was significantly associated (P < 0.05) with atrophy of left planum temporale, angular gyrus and anterior cingulate gyrus: a cortical network that has previously been widely implicated in processing degraded speech signals. Our findings suggest that the comprehension of acoustically altered speech captures an auditory brain process relevant to daily hearing and communication in major dementia syndromes, with novel diagnostic and therapeutic implications.

[A Case of Amyotrophic Lateral Sclerosis with Semantic Variant Primary Progressive Aphasia: A Study of Language Symptoms and Agraphia]

The patient was a 66-year-old man brought to the emergency room with impaired consciousness due to hypercarbonemia, managed on a respirator, and diagnosed with amyotrophic lateral sclerosis (ALS). MRI showed atrophy of the anterior and medial surfaces of the bilateral temporal lobes that was more severe in the right side. The patient had dysgraphia in both kana and kanji. Detailed examinations of the language function revealed impaired single-word comprehension, impaired naming, and surface dysgraphia, leading to the diagnosis of semantic variant primary progressive aphasia (svPPA). ALS patients with atrophy of the anterior temporal lobe and surface dysgraphia of kanji may have svPPA as a complication. (Received April 14, 2023; Accepted June 21, 2023; Published October 1, 2023).

Differential approach to stroke aphasia and primary progressive aphasia using transcranial magnetic stimulation: A systematic review

Language disorders can occur as a consequence of stroke or neurodegenerative disorders, among other causes. Post‑stroke aphasia (PSA) and primary progressive aphasia (PPA) are syndromes that, despite having common features, differ in the brain mechanisms that cause their symptoms. These differences in the underlying functional neuroanatomical changes may influence the way they are addressed by different non‑invasive brain stimulation techniques and, in particular, by repetitive transcranial magnetic stimulation (rTMS). The aim of this systematic review is to evaluate the efficacy of rTMS in the treatment of PSA and PPA, as well as the differences in the approach to these disorders using rTMS. To this end, a total of 36 articles were found in the Web of Science, Scopus, and PubMed. The results obtained suggest that whereas in PSA, the selection of the stimulation paradigm is based on bi‑hemispheric functional reorganisation models with a tendency towards the application of inhibitory rTMS in the contralateral right hemisphere, in PPA, the application of excitatory rTMS in functionally compromised areas seems to show promising changes. It is concluded that rTMS is a potential treatment in the therapy of both disorders, although differences in the underlying brain mechanisms differentiate the rTMS approach in each case.

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

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

Composite Indices of the Color-Picture Version of Boston Naming Test Have Better Discriminatory Power: Reliability and Validity in a Chinese Sample with Diverse Neurodegenerative Diseases

BACKGROUND

The Boston Naming Test (BNT) is the most widely used measure to assess anomia. However, it has been criticized for failing to differentiate the underlying cognitive process of anomia.

OBJECTIVE

We validated the color-picture version of BNT (CP-BNT) in a sample with diverse neurodegenerative dementia diseases (NDDs). We also verified the differential ability of the composite indices of CP-BNT across NDDs groups.

METHODS

The present study included Alzheimer's disease (n = 132), semantic variant primary progressive aphasia (svPPA, n = 53), non-svPPA (n = 33), posterior cortical atrophy (PCA, n = 35), and normal controls (n = 110). We evaluated psychometric properties of CP-BNT for the spontaneous naming (SN), the percentage of correct responses on semantic cuing and word recognition cuing (% SC, % WR). Receiver operating characteristic analysis was used to examine the discriminatory power of SN alone and the composite indices (SN, % SC, and % WR).

RESULTS

The CP-BNT had sufficient internal consistency, good convergent, divergent validity, and criterion validity. Different indices of CP-BNT demonstrated distinct cognitive underpinnings. Category fluency was the strongest predictor of SN (β= 0.46, p < 0.001). Auditory comprehension tests highly associated with % WR (Sentence comprehension: β= 0.22, p = 0.001; Word comprehension: β= 0.20, p = 0.001), whereas a lower visuospatial score predicted % SC (β= -0.2, p = 0.001). Composite indices had better predictability than the SN alone when differentiating between NDDs, especially for PCA versus non-svPPA (area under the curve increased from 63.9% to 81.2%).

CONCLUSION

The CP-BNT is a highly linguistically relevant test with sufficient reliability and validity. Composite indices could provide more differential information beyond SN and should be used in clinical practice.

Writing errors in primary progressive aphasia

Peripheral errors in writing, that is errors produced download the spelling, have been occasionally described in primary progressive aphasia (PPA), but the possibility that these errors might be a marker of parkinsonism associated to some subtypes of PPA has not been explored. We investigated whether errors of peripheral nature characterize the writing disorder in PPA when associated with parkinsonian signs (PSs). Subgroups of PPA without PSs and with PSs were studied. The proportion of the central and peripheral errors in writing words and pseudowords was calculated in each group. In writing words, central errors significantly exceeded peripheral errors in subgroups without PSs. The higher the number of peripheral errors, the higher the probability of presenting PSs. No relation emerged between any error and the Unified Parkinson's Disease Rating Scale, but both types of errors correlated with measures of cognitive ability. Peripheral errors emerge when PSs are associated with PPA and may be linked to a decay of the cognitive control on movement, possibly involving the right hemisphere. Peripheral errors have clinical relevance in PPA, to the extent that they may assume the significance of a marker of specific subtypes and can help to outline the specific clinical picture of individual patients.

Tractography of supplementary motor area projections in progressive speech apraxia and aphasia

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Degeneration of SMA white matter tracts occurs in progressive apraxia of speech.

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SMA commissural, putamen and precentral tracts were associated with speech apraxia.

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Agrammatism was associated with SMA-prefrontal and frontal aslant tracts.

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Tract profile analysis suggests different disease epicenters across syndromes.

Progressive apraxia of speech (AOS) is a motor speech disorder affecting the ability to produce phonetically or prosodically normal speech. Progressive AOS can present in isolation or co-occur with agrammatic aphasia and is associated with degeneration of the supplementary motor area. We aimed to assess breakdowns in structural connectivity from the supplementary motor area in patients with any combination of progressive AOS and/or agrammatic aphasia to determine which supplementary motor area tracts are specifically related to these clinical symptoms. Eighty-four patients with progressive AOS or progressive agrammatic aphasia were recruited by the Neurodegenerative Research Group and underwent neurological, speech/language, and neuropsychological testing, as well as 3 T diffusion magnetic resonance imaging. Of the 84 patients, 36 had apraxia of speech in isolation (primary progressive apraxia of speech, PPAOS), 40 had apraxia of speech and agrammatic aphasia (AOS-PAA), and eight had agrammatic aphasia in isolation (progressive agrammatic aphasia, PAA). Tractography was performed to identify 5 distinct tracts connecting to the supplementary motor area. Fractional anisotropy and mean diffusivity were assessed at 10 positions along the length of the tracts to construct tract profiles, and median profiles were calculated for each tract. In a case-control comparison, decreased fractional anisotropy and increased mean diffusivity were observed along the supplementary motor area commissural fibers in all three groups compared to controls. PPAOS also had abnormal diffusion in tracts from the supplementary motor area to the putamen, prefrontal cortex, Broca’s area (frontal aslant tract) and motor cortex, with greatest abnormalities observed closest to the supplementary motor area. The AOS-PAA group showed abnormalities in the same set of tracts, but with greater involvement of the supplementary motor area to prefrontal tract compared to PPAOS. PAA showed abnormalities in the left prefrontal and frontal aslant tracts compared to both other groups, with PAA showing greatest abnormalities furthest from the supplementary motor area. Severity of AOS correlated with tract metrics in the supplementary motor area commissural and motor cortex tracts. Severity of aphasia correlated with the frontal aslant and prefrontal tracts. These findings provide insight into how AOS and agrammatism are differentially related to disrupted diffusivity, with progressive AOS associated with abnormalities close to the supplementary motor area, and the frontal aslant and prefrontal tracts being particularly associated with agrammatic aphasia.

Longitudinal study of primary progressive aphasia in a patient with pathologically diagnosed Alzheimer's disease: a case report

BACKGROUND

Alzheimer's disease is a neurodegenerative disease involving the deposition of pathologic amyloid-β and tau protein in the cerebral cortex. Alzheimer's disease is commonly characterized by progressive impairment of recent memory. Primary progressive aphasia is also often observed in patients with Alzheimer's disease. Moreover, language-associated symptoms, such as primary progressive aphasia, are diverse and varied in Alzheimer's disease. However, nonfluent/agrammatic variant primary progressive aphasia is not generally considered a symptom of Alzheimer's disease. To date, there has been no longitudinal study of primary progressive aphasia in Japanese-speaking patients or in patients speaking other languages with pathologically diagnosed Alzheimer's disease. Here we present a longitudinal study of primary progressive aphasia in a Japanese patient pathologically diagnosed with Alzheimer's disease.

CASE PRESENTATION

A 75-year-old Japanese man, whose wife reported that his memory was impaired, also suffered from suspected aphasia. He was pathologically diagnosed with Alzheimer's disease using 11C-Pittsburgh compound-B positron emission tomography and 18F-THK5351 positron emission tomography. Based on clinical observation and the results of the Japanese standard language test of aphasia, he was also diagnosed with nonfluent/agrammatic variant primary progressive aphasia. During the subsequent 2 years, his cognitive impairment, aphasia, and behavioral and psychological symptoms of dementia progressed. Furthermore, progression of pathologic amyloid-β and tau protein deposition was revealed through 11C-Pittsburgh compound-B positron emission tomography and 18F-THK5351 positron emission tomography. Although the results of [123I] iodoamphetamine single-photon emission computed tomography suggested corticobasal degeneration, this was not observed on the [123I] FP-CIT single-photon emission computed tomography (SPECT) (DaTscan). A previous study had reported that Alzheimer's disease with a nonfluent/agrammatic variant primary progressive aphasia was accompanied by corticobasal degeneration; however, this was not true in our case.

CONCLUSIONS

This is possibly the first longitudinal study of nonfluent/agrammatic variant primary progressive aphasia in a Japanese-speaking patient with pathologically diagnosed Alzheimer's disease, but without corticobasal degeneration.

[Classification and Diagnosis of Primary Progressive Aphasia]

I have introduced primary progressive aphasia (PPA) with regard to frontotemporal lobar degeneration (FTLD) and evaluated the following elementary language symptoms for its diagnosis: agrammatism in speech production, apraxia of speech, phonemic paraphasia, naming impairment, impairment of single-word comprehension, and repetition. Furthermore, I have described the clinical symptoms, causative lesions, and pathological findings of three PPA variants -nonfluent/agrammatic, semantic, and logopenic PPA- according to the criteria proposed by Gorno-Tempni et al. (2011).

APOE is a correlate of phenotypic heterogeneity in Alzheimer disease in a national cohort

OBJECTIVE

To compare the proportion of APOE ε4 genotype carriers in aphasic vs amnestic variants of Alzheimer disease (AD).

METHOD

The proportion of APOE ε4 carriers was compared among the following 3 groups: (1) 42 patients with primary progressive aphasia (PPA) and AD pathology (PPA/AD) enrolled in the Northwestern Alzheimer Disease Center Clinical Core; (2) 1,418 patients with autopsy-confirmed AD and amnestic dementia of the Alzheimer type (DAT/AD); and (3) 2,608 cognitively normal controls (NC). The latter 2 groups were compiled from the National Alzheimer Coordinating Center database. Logistic regression models analyzed the relationship between groups and APOE ε4 carrier status, adjusting for age at onset and sex as needed.

RESULTS

Using NC as the reference and adjusting for sex and age, the DAT/AD group was 3.97 times more likely to be APOE ε4 carriers. Adjusting for sex and age at symptom onset, the DAT/AD group was 2.46 times as likely to be carriers compared to PPA/AD. There was no significant difference in the proportion of APOE ε4 carriers for PPA/AD compared to NC. PPA subtypes included 24 logopenic, 10 agrammatic nonfluent, and 8 either mixed (n = 5) or too severe (n = 3) to subtype. The proportion of carriers and noncarriers was similar for logopenic and agrammatic subtypes, both having fewer carriers.

CONCLUSION

The proportion of APOE ε4 carriers was elevated in amnestic but not aphasic manifestations of AD. These results suggest that APOE ε4 is an anatomically selective risk factor that preferentially increases the vulnerability to AD pathology of memory-related medial temporal areas rather than language-related neocortices.

Early pathological gambling in co-occurrence with semantic variant primary progressive aphasia: a case report

We have comprehensively documented a case of semantic variant of primary progressive aphasia (sv-PPA) presenting with early-onset pathological gambling (PG). While a growing number of studies have shown the presence of behavioral alterations in patients with sv-PPA, PG has been observed only in the behavioral variant of frontotemporal dementia (bv-FTD). To date, no case of PG with the co-occurrence of prominent semantic deficits at the onset of the disease has been reported in the literature. Impulse disorders at onset may wrongly lead to a misdiagnosis (ie, psychiatric disorders). Therefore, a wider characterization of cognitive/aphasia symptoms in patients presenting impulse disorders and predominant language dysfunctions is recommended.

Single-word comprehension deficits in the nonfluent variant of primary progressive aphasia

BACKGROUND

A subset of patients with the nonfluent variant of primary progressive aphasia (PPA) exhibit concomitant single-word comprehension problems, constituting a 'mixed variant' phenotype. This phenotype is rare and currently not fully characterized. The aim of this study was twofold: to assess the prevalence and nature of single-word comprehension problems in the nonfluent variant and to study multimodal imaging characteristics of atrophy, tau, and amyloid burden associated with this mixed phenotype.

METHODS

A consecutive memory-clinic recruited series of 20 PPA patients (12 nonfluent, five semantic, and three logopenic variants) were studied on neurolinguistic and neuropsychological domains relative to 64 cognitively intact healthy older control subjects. The neuroimaging battery included high-resolution volumetric magnetic resonance imaging processed with voxel-based morphometry, and positron emission tomography with the tau-tracer [18F]-THK5351 and amyloid-tracer [11C]-Pittsburgh Compound B.

RESULTS

Seven out of 12 subjects who had been classified a priori with nonfluent variant PPA showed deficits on conventional single-word comprehension tasks along with speech apraxia and agrammatism, corresponding to a mixed variant phenotype. These mixed variant cases included three females and four males, with a mean age at onset of 65 years (range 44-77 years). Object knowledge and object recognition were additionally affected, although less severely compared with the semantic variant. The mixed variant was characterized by a distributed atrophy pattern in frontal and temporoparietal regions. A more focal pattern of elevated [18F]-THK5351 binding was present in the supplementary motor area, the left premotor cortex, midbrain, and basal ganglia. This pattern was closely similar to that seen in pure nonfluent variant PPA. At the individual patient level, elevated [18F]-THK5351 binding in the supplementary motor area and premotor cortex was present in six out of seven mixed variant cases and in five and four of these cases, respectively, in the thalamus and midbrain. Amyloid biomarker positivity was present in two out of seven mixed variant cases, compared with none of the five pure nonfluent cases.

CONCLUSIONS

A substantial proportion of PPA patients with speech apraxia and agrammatism also have single-word comprehension deficits. At the neurobiological level, the mixed variant shows a high degree of similarity with the pure nonfluent variant of PPA.

TRIAL REGISTRATION

EudraCT, 2014-002976-10 . Registered on 13-01-2015.

Data-driven classification of patients with primary progressive aphasia

Current diagnostic criteria classify primary progressive aphasia into three variants-semantic (sv), nonfluent (nfv) and logopenic (lv) PPA-though the adequacy of this scheme is debated. This study took a data-driven approach, applying k-means clustering to data from 43 PPA patients. The algorithm grouped patients based on similarities in language, semantic and non-linguistic cognitive scores. The optimum solution consisted of three groups. One group, almost exclusively those diagnosed as svPPA, displayed a selective semantic impairment. A second cluster, with impairments to speech production, repetition and syntactic processing, contained a majority of patients with nfvPPA but also some lvPPA patients. The final group exhibited more severe deficits to speech, repetition and syntax as well as semantic and other cognitive deficits. These results suggest that, amongst cases of non-semantic PPA, differentiation mainly reflects overall degree of language/cognitive impairment. The observed patterns were scarcely affected by inclusion/exclusion of non-linguistic cognitive scores.

Is "Learning" episodic memory? Distinct cognitive and neuroanatomic correlates of immediate recall during learning trials in neurologically normal aging and neurodegenerative cohorts

Although commonly interpreted as a marker of episodic memory during neuropsychological exams, relatively little is known regarding the neurobehavior of "total learning" immediate recall scores. Medial temporal lobes are clearly associated with delayed recall performances, yet immediate recall may necessitate networks beyond traditional episodic memory. We aimed to operationalize cognitive and neuroanatomic correlates of total immediate recall in several aging syndromes. Demographically-matched neurologically normal adults (n=91), individuals with Alzheimer's disease (n=566), logopenic variant primary progressive aphasia (PPA) (n=34), behavioral variant frontotemporal dementia (n=97), semantic variant PPA (n=71), or nonfluent/agrammatic variant PPA (n=39) completed a neurocognitive battery, including the CVLT-Short Form trials 1-4 Total Immediate Recall; a majority subset also completed a brain MRI. Regressions covaried for age and sex, and MMSE in cognitive and total intracranial volume in neuroanatomic models. Neurologically normal adults demonstrated a heterogeneous pattern of cognitive associations with total immediate recall (executive, speed, delayed recall), such that no singular cognitive or neuroanatomic correlate uniquely predicted performance. Within the clinical cohorts, there were syndrome-specific cognitive and neural associations with total immediate recall; e.g., semantic processing was the strongest cognitive correlate in svPPA (partial r=0.41), while frontal volumes was the only meaningful neural correlate in bvFTD (partial r=0.20). Medial temporal lobes were not independently associated with total immediate recall in any group (ps>0.05). Multiple neurobehavioral systems are associated with "total learning" immediate recall scores that importantly differ across distinct clinical syndromes. Conventional memory networks may not be sufficient or even importantly contribute to total immediate recall in many syndromes. Interpreting learning scores as equivalent to episodic memory may be erroneous.

Augmentative and Alternative Communication (AAC) for a patient with a nonfluent/agrammatic variant of PPA in the mutism stage

INTRODUCTION

The paper presents an example of the successful administration of the Augmentative and Alternative Communication (AAC) system. Such an approach is of particular significance in cases of patients with speech and language deterioration, which is observed in a nonfluent/agrammatic variant of primary progressive aphasia (PPA-G). Regaining the ability to communicate with others proves to be very important for the patients' self-esteem and enables them to restore previously broken social bonds.

CASE HISTORY

The patient A.G., aged 73, a right-handed woman, had been a teacher of Polish before suffering from speech disorders of the PPA-G type. As the disease progressed, her communication deteriorated and finally she developed mutism. The patient was given a clinical and imaging-supported diagnosis of an isolated nonfluent/ agrammatic variant of primary progressive aphasia (PPA-G). The Augmentative and Alternative Communication (AAC) system specially designed for her needs was introduced to help the patient to regain the possibility to communicate. After 20 sessions of training with the use of simple equipment she was again able to communicate non-verbally with her son and with the staff of the nursing home. At the same time, a considerable improvements in her social functioning, including daily activities, was observed.

CONCLUSIONS

Loss of the ability to communicate with others has a serious impact upon a patient's quality of life, and often results in withdrawal and an inability to lead an independent life. The introduction of the Augmentative and Alternative Communication (AAC) system proves to be a great help, not only for regaining the ability to communicate, but also for the restoration of social bonds. In consequence, the previously mute patient begins to show signs of social cooperation.

Childhood Learning Disabilities and Atypical Dementia: A Retrospective Chart Review

Objective

To further our understanding of the association between self-reported childhood learning disabilities (LDs) and atypical dementia phenotypes (Atypical Dementia), including logopenic primary progressive aphasia (L-PPA), Posterior Cortical Atrophy (PCA), and Dysexecutive-type Alzheimer’s Disease (AD).

Methods

This retrospective case series analysis of 678 comprehensive neuropsychological assessments compared rates of self-reported LD between dementia patients diagnosed with Typical AD and those diagnosed with Atypical Dementia. 105 cases with neuroimaging or CSF data available and at least one neurology follow-up were identified as having been diagnosed by the neuropsychologist with any form of neurodegenerative dementia. These cases were subject to a consensus diagnostic process among three dementia experts using validated clinical criteria for AD and PPA. LD was considered Probable if two or more statements consistent with prior LD were documented within the Social & Developmental History of the initial neuropsychological evaluation.

Results

85 subjects (Typical AD n=68, Atypical AD n=17) were included in the final analysis. In logistic regression models adjusted for age, gender, handedness, education and symptom duration, patients with Probable LD, compared to patients without Probable LD, were significantly more likely to be diagnosed with Atypical Dementia vs. Typical AD (OR 13.1, 95% CI 1.3-128.4). All three of the L-PPA cases reporting a childhood LD endorsed childhood difficulty with language. By contrast, both PCA cases reporting Probable childhood LD endorsed difficulty with attention and/or math.

Conclusions

In people who develop dementia, childhood LD may predispose to atypical phenotypes. Future studies are required to confirm whether atypical neurodevelopment predisposes to regional-specific neuropathology in AD and other dementias.

Identification of an atypical variant of logopenic progressive aphasia

The purpose of this study was to examine the association between aphasia severity and neurocognitive function, disease duration and temporoparietal atrophy in 21 individuals with the logopenic variant of primary progressive aphasia (lvPPA). We found significant correlations between aphasia severity and degree of neurocognitive impairment as well as temporoparietal atrophy; but not disease duration. Cluster analysis identified three variants of lvPPA: (1) subjects with mild aphasia and short disease duration (mild typical lvPPA); (2) subjects with mild aphasia and long disease duration (mild atypical lvPPA); and, (3) subjects with severe aphasia and relatively long disease duration (severe typical lvPPA). All three variants showed temporoparietal atrophy, with the mild atypical group showing the least atrophy despite the longest disease duration. The mild atypical group also showed mild neuropsychological impairment. The subjects with mild aphasia and neuropsychological impairment despite long disease duration may represent a slowly progressive variant of lvPPA.

Ideomotor apraxia in agrammatic and logopenic variants of primary progressive aphasia

There are few studies examining praxis in subjects with primary progressive aphasia. The aim of this study was to examine the pattern and severity of ideomotor apraxia in subjects with logopenic and agrammatic variants of primary progressive aphasia and to determine if the presence of ideomotor apraxia correlated with specific neuroanatomical structural abnormalities. Subjects with primary progressive aphasia were prospectively recruited and classified according to published criteria. Using the apraxia subtest of the Western Aphasia Battery, pattern and severity of ideomotor apraxia was examined in all subjects diagnosed with agrammatic and logopenic variants of primary progressive aphasia. The study included 47 subjects, 21 diagnosed with agrammatic variant of primary progressive aphasia and 26 with logopenic variant primary progressive aphasia. Subjects with agrammatic aphasia were older at onset than the logopenic variant (67.2 vs. 61.7 years, p = 0.02), but there was no difference in illness duration prior to evaluation. Those with logopenic aphasia showed more cognitive impairment on the Mini-Mental Status Examination (agrammatic = 26.7/30, logopenic = 22/30, p = 0.002), and a trend for more severe language impairment as measured by the Western Aphasia Battery-Aphasia Quotient (agrammatic = 82.3, logopenic = 75.2, p = 0.11). Strong correlations were found between Western Aphasia Battery-Aphasia Quotient and total apraxia, instrumental apraxia, and complex apraxia, while average to modest correlations were seen with upper limb apraxia and facial apraxia. After adjusting for age, mental status performance, and Western Aphasia Battery-Aphasia Quotient score, those with agrammatic aphasia had a higher degree of total apraxia (p = 0.004), facial apraxia (p = 0.03), instrumental apraxia (p = 0.0006), and complex apraxia (p = 0.0006) than those with logopenic aphasia. The agrammatic variant of primary progressive aphasia was associated with greater praxis deficits but less cognitive impairment than the logopenic variant. The presence of ideomotor apraxia was associated with grey matter loss in the left lateral premotor cortex with extension into the motor cortex. These findings suggest that although some affected areas in the agrammatic and logopenic variants of primary progressive aphasia overlap, there exists an area that is more affected in the agrammatic variant than the logopenic variant that accounts for the greater association of agrammatic aphasia with ideomotor apraxia.

The diagnosis and understanding of apraxia of speech: why including neurodegenerative etiologies may be important

PURPOSE

To discuss apraxia of speech (AOS) as it occurs in neurodegenerative disease (progressive AOS [PAOS]) and how its careful study may contribute to general concepts of AOS and help refine its diagnostic criteria.

METHOD

The article summarizes our current understanding of the clinical features and neuroanatomical and pathologic correlates of PAOS and its relationship to primary progressive aphasia (PPA). It addresses similarities and differences between PAOS and stroke-induced AOS that may be relevant to improving our understanding of AOS in general.

CONCLUSIONS

PAOS is clinical disorder that should be distinguished from PPA. Its recognition is important to clinical care provided by speech-language pathologists, but it also has implications for neurologic localization and diagnosis as well as prediction of underlying pathology and histochemistry. The clinical features of PAOS and stroke-induced AOS have not been explicitly compared, but they may not be identical because PAOS does not follow a vascular distribution, the brunt of cortical pathology is in the premotor and supplementary motor area, and its onset (rather than acute) is slowly progressive with potential for adaptation to gradual impairment. Careful description and study of PAOS may be a valuable source of information for refining our understanding of AOS in general.

The time course of neurolinguistic and neuropsychological symptoms in three cases of logopenic primary progressive aphasia

Primary progressive aphasia (PPA) is a rare clinical dementia syndrome affecting predominantly language abilities. Word-finding difficulties and comprehension deficits despite relatively preserved cognitive functions are characteristic symptoms during the first two years, and distinguish PPA from other dementia types like Alzheimer's disease. However, the dynamics of changes in language and non-linguistic abilities are not well understood. Most studies on progression used cross-sectional designs, which provide only limited insight into the course of the disease. Here we report the results of a longitudinal study in three cases of logopenic PPA over a period of 18 months, with exemplary longitudinal data from one patient even over 46 months. A comprehensive battery of neurolinguistic and neuropsychological tests was applied four times at intervals of six months. Over this period, deterioration of verbal abilities such as picture naming, story retelling, and semantic word recall was found, and the individual decline was quantified and compared between the three patients. Furthermore, decrease in non-verbal skills such as divided attention and increasing apraxia was observed in all three patients. In addition, inter-subject variability in the progression with different focuses was observed, with one patient developing a non-fluent PPA variant. The longitudinal, multivariate investigation of logopenic PPA thus provides novel insights into the progressive deterioration of verbal as well as non-verbal abilities. These deficits may further interact and thus form a multi-causal basis for the patients' problems in every-day life which need to be considered when planning individually targeted intervention in PPA.

Primary progressive aphasias and their contribution to the contemporary knowledge about the brain-language relationship

Primary progressive aphasia (PPA), typically resulting from a neurodegenerative disease such as frontotemporal dementia/Pick Complex or Alzheimer's disease, is a heterogeneous clinical condition characterized by a progressive loss of specific language functions with initial sparing of other cognitive domains. Based on the constellation of symptoms, PPA has been classified into a nonfluent, semantic, or logopenic variant. This review of the literature aims to characterize the speech and language impairment, cognition, neuroimaging, pathology, genetics, and epidemiology associated with each of these variants. Some therapeutic recommendations, theoretical implications, and directions for future research have been also provided.

The nature of naming errors in primary progressive aphasia versus acute post-stroke aphasia

OBJECTIVE

To compare the distribution of error types across subgroups of primary progressive aphasia and poststroke aphasia in different vascular locations.

METHOD

We analyzed naming errors in 49 individuals with acute left hemisphere ischemic stroke and 55 individuals with three variants of primary progressive aphasia. Location of atrophy or ischemic stroke was characterized using MRI.

RESULTS

We found that distribution of error types was very similar across all subgroups, irrespective of the site or etiology of the lesion. The only significant difference across groups was the percentage of circumlocutions (F(7, 96) = 3.02, p = .005). Circumlocution errors were highest among logopenic variant PPA (24%) and semantic variant PPA (24%). Semantic coordinate errors were common in all groups, probably because they can arise from disruption of different cognitive processes underlying naming and, therefore, from different locations of brain damage.

CONCLUSIONS

Semantic errors are common among all types of primary progressive aphasia and poststroke aphasia, and the type of error depends in part on the location of damage.

Connected speech production in three variants of primary progressive aphasia

Primary progressive aphasia is a clinical syndrome defined by progressive deficits isolated to speech and/or language, and can be classified into non-fluent, semantic and logopenic variants based on motor speech, linguistic and cognitive features. The connected speech of patients with primary progressive aphasia has often been dichotomized simply as 'fluent' or 'non-fluent', however fluency is a multidimensional construct that encompasses features such as speech rate, phrase length, articulatory agility and syntactic structure, which are not always impacted in parallel. In this study, our first objective was to improve the characterization of connected speech production in each variant of primary progressive aphasia, by quantifying speech output along a number of motor speech and linguistic dimensions simultaneously. Secondly, we aimed to determine the neuroanatomical correlates of changes along these different dimensions. We recorded, transcribed and analysed speech samples for 50 patients with primary progressive aphasia, along with neurodegenerative and normal control groups. Patients were scanned with magnetic resonance imaging, and voxel-based morphometry was used to identify regions where atrophy correlated significantly with motor speech and linguistic features. Speech samples in patients with the non-fluent variant were characterized by slow rate, distortions, syntactic errors and reduced complexity. In contrast, patients with the semantic variant exhibited normal rate and very few speech or syntactic errors, but showed increased proportions of closed class words, pronouns and verbs, and higher frequency nouns, reflecting lexical retrieval deficits. In patients with the logopenic variant, speech rate (a common proxy for fluency) was intermediate between the other two variants, but distortions and syntactic errors were less common than in the non-fluent variant, while lexical access was less impaired than in the semantic variant. Reduced speech rate was linked with atrophy to a wide range of both anterior and posterior language regions, but specific deficits had more circumscribed anatomical correlates. Frontal regions were associated with motor speech and syntactic processes, anterior and inferior temporal regions with lexical retrieval, and posterior temporal regions with phonological errors and several other types of disruptions to fluency. These findings demonstrate that a multidimensional quantification of connected speech production is necessary to characterize the differences between the speech patterns of each primary progressive aphasic variant adequately, and to reveal associations between particular aspects of connected speech and specific components of the neural network for speech production.

Reading disorders in primary progressive aphasia: a behavioral and neuroimaging study

Previous neuropsychological studies on acquired dyslexia revealed a double dissociation in reading impairments. Patients with phonological dyslexia have selective difficulty in reading pseudo-words, while those with surface dyslexia misread exception words. This double dissociation in reading abilities has often been reported in brain-damaged patients, but it has not been consistently shown in patients with neurodegenerative diseases. In this study, we investigated reading impairments and their anatomical correlates in various neurodegenerative diseases. First, we performed a behavioral analysis to characterize the reading of different word types in primary progressive aphasia (PPA). Then, we conducted a voxel-based morphometry neuroimaging study to map the brain areas in which gray matter volume correlated with the accurate reading of exception and pseudo-words. The results showed a differential pattern of exception and pseudo-word reading abilities in different clinical variants of PPA. Patients with semantic dementia, a disorder characterized by selective loss of semantic memory, revealed a pattern of surface dyslexia, while patients with logopenic/phonological progressive aphasia, defined by phonological loop deficits, showed phonological dyslexia. Neuroimaging results showed that exception word reading accuracy correlated with gray matter volume in the left anterior temporal structures, including the temporal pole, the anterior superior and middle temporal and fusiform gyri, while pseudo-word reading accuracy correlated with left temporoparietal regions, including the posterior superior and middle temporal and fusiform gyri, and the inferior parietal lobule. These results suggest that exception and pseudo-word reading not only rely upon different language mechanisms selectively damaged in PPA, but also that these processes are sustained by separate brain structures.

Covert processing of words and pictures in nonsemantic variants of primary progressive aphasia

The inability to name objects (anomia) is one of the most common findings in the neurologic examination of primary progressive aphasia (PPA). In the semantic variant of PPA, the anomia is profound and reflects a combination of object naming and word comprehension deficits. In contrast, nonsemantic variants of PPA display a more selective impairment of object naming, without corresponding impairments of word comprehension. The aim of the present study was to explore the nature of the anomia in nonsemantic variants of PPA with a sensitive chronometric test of covert word/picture association. We tested priming effects in 12 patients with nonsemantic variant of PPA and 18 controls. Stimuli consisted of written words and line pictures of concrete objects. Within-format (word-word and picture-picture) and cross-format (word-picture and picture-word) priming effects were assessed by measuring the shortening of response times to the second versus initial presentation of corresponding stimulus pairs. In addition to the expected impairment of picture-to-word priming, a condition simulating object naming, the nonsemantic PPA patients also showed unexpected impairments of word-to-picture and word-to-word priming. Picture-to-picture priming was preserved, demonstrating the selectivity of the deficit for lexical processing. These findings show that the information processing bottleneck in patients with nonsemantic variants of PPA is not confined to the stage of lexical access but that it also extends into the prior levels of lexical semantics. The boundaries between the semantic and nonsemantic variants are therefore far from rigid.

Clusters of cognitive and behavioral disorders clearly distinguish primary progressive aphasia from frontal lobe dementia, and Alzheimer's disease

BACKGROUND/AIMS

Frontal lobe dementia (FLD) and primary nonfluent progressive aphasia (PnPA) are two forms of frontotemporal lobe degeneration. The relationship between these conditions remains unclear. Our study aimed to better define the behavioral and cognitive clusters characterizing PnPA patients.

METHODS

We cognitively and behaviorally evaluated three groups of newly diagnosed patients affected by Alzheimer's disease (AD, n=20), FLD (n=22) and PnPA (n=10), in order to assess the cognitive-behavioral pattern of PnPA, compared to both FLD and AD.

RESULTS

We found, as expected, worse performances in episodic memory in AD, of both the verbal fluency and naming tasks in PnPA, while FLD mainly showed behavioral disorders associated with an unremarkable deficit in the executive tasks. PnPA was not characterized by any significant behavioral disorders. Factor analysis-extracted three main factors ('mnesic', 'behavioral' and 'linguistic') clearly correlated to each group. A discriminant analysis based on the extracted factors correctly classified 84.6% of all patients.

CONCLUSION

The evidence of a characteristics cognitive profile, without any significant behavioral changes, highlights that PnPA is different from other forms of frontotemporal lobe degeneration regarding both the cognitive and behavioral patterns; thus, it should be considered independently in further studies.

[Frontotemporal dementia]

Frontotemporal dementia usually begins before the age of 65 years. It is manifested by behavioral and language disorders. The lesions observed in frontotemporal dementia affect the frontal and temporal lobes bilaterally. One third of patients have a psychiatric diagnosis at the onset of disease. The genetic component is important: 30-50% of patients have a family history of this disease. Cholinergic effects are not associated with frontotemporal dementia and therefore anticholinesterase treatment is not indicated.

Is slowly progressive anarthria a "pure" motor-speech disorder? Evidence from writing performance

It is usually assumed that writing is normal in patients with anarthria, but a careful examination of the literature shows that they produce deletions, transpositions and insertions. Indeed, a matter of debate concerns the distinction between primary progressive aphasia (PPA) and slowly progressive anarthria (SPA). If writing deficits were purely linguistic errors, then there would be no reason to consider slowly progressive anarthria as distinct from non-fluent PPA. We report the case of a patient with SPA in whom writing abilities were specifically assessed. No lexical-semantic deficits were detected, but errors were deletions, substitutions or transpositions, with no frequency, length or lexicality effect; moreover, controls produced the same kind of errors during articulatory suppression. It is suggested that subvocal rehearsal plays a role in writing, allowing the conversion/assembly of the phonological string in a graphemic representation. Therefore, writing deficits do not appear to have a linguistic basis and SPA seems distinguishable from nonfluent forms of aphasia.

A longitudinal study of sentence comprehension difficulty in primary progressive aphasia

CONTEXT

Patients with primary progressive aphasia have sentence comprehension difficulty, but the longitudinal course of this deficit has not been investigated.

OBJECTIVE

To determine how grammatical, single word meaning, and working memory factors contribute to longitudinal decline of sentence comprehension in primary progressive aphasia. We hypothesised partially distinct patterns of sentence comprehension difficulty in subgroups of patients with progressive non-fluent aphasia (PNFA) and semantic dementia (SD).

DESIGN

Cohort.

SETTING

Institutional out patient referral centre.

PATIENTS

PNFA (n = 14), SD (n = 10).

MAIN OUTCOME MEASURE

Sentence comprehension accuracy.

RESULTS

PNFA patients were significantly impaired at understanding grammatically complex sentences when first seen, and this was more evident than impairment of their comprehension of grammatically simple sentences (p<0.05). Comprehension of grammatically complex sentences correlated with their working memory deficit at presentation (p<0.05). PNFA patients showed modest decline over time in grammatical comprehension. In SD, comprehension of grammatically complex sentences was not more impaired than comprehension of grammatically simple sentences when first seen, but these patients demonstrated a significant longitudinal decline in understanding grammatically complex sentences (p<0.05). Cox regression analyses showed that a deficit in single word meaning contributes to the progressive impairment for grammatically complex sentences in SD (p<0.05), but working memory does not contribute to longitudinal decline in PNFA.

CONCLUSION

Patients with PNFA and SD have sentence comprehension difficulty, but distinct factors contribute to this impairment during the course of their disease.

Speech and language in progressive nonfluent aphasia compared with early Alzheimer's disease

BACKGROUND

Progressive nonfluent aphasia (PA) is a slow deterioration of language that remains relatively isolated from other cognitive or behavioral deficits for at least 2 years. The differentiation of PA from early Alzheimer's disease (AD) is important, given the presence of early language changes in AD.

METHODS

A language assessment was administered to 15 patients who met established criteria for PA, 15 patients with clinically probable AD and mild dementia, and 15 normal control subjects. The language battery included verbal fluency, the Boston Naming Test with cuing and recognition, and an aphasia test battery with a motor speech exam.

RESULTS

Pronounced literal paraphasic errors distinguished the PA patients from the AD patients. The PA group had anomia, decreased letter fluency, neologisms, difficulty on phrase repetition, decreased phrase length, and a decreased rate of verbal output. Interference from paraphasic anomia accounted for much of their decreased fluency.

CONCLUSION

Many patients with PA have a primary defect in accessing sound-based representation of speech (phonemes), similar to conduction aphasia, possibly as a consequence of disturbed white matter tracts in the left superior temporal region.

A case of cortical deafness and anarthria

Generally, cortical deafness is not complicated by anarthria and cortical anarthria does not affect auditory perception. We report a case of simultaneous progressive cortical deafness and anarthria. At the age of 70 years, the patient, a woman, noticed hearing problems when using the telephone, which worsened rapidly over the next 2 years. She was then referred to our hospital for further examinations of her hearing problems. Auditory tests revealed threshold elevation in the low and middle frequencies on pure-tone audiometry, a maximum speech discrimination of 25% and normal otoacoustic emissions and auditory brainstem, middle- and long-latency responses. An articulation test revealed abnormal pronunciation. Because of these problems only written and not verbal communication was possible; her ability to read and write was unimpaired. She showed no other neurological problems. Brain MRI demonstrated atrophic changes of the auditory cortex and Wernicke's language center and PET suggested low uptake of (18F) 2-fluoro-2-deoxy-d-glucose around the Sylvian fissures in both hemispheres. Neurologically, the patient was suspected of having progressive aphasia or frontotemporal dementia. Her cortical deafness and anarthria are believed to be early signs of this entity.

Progressive dysarthria: definition and clinical follow-up

Progressive dysarthria is a common sign of several degenerative disorders of the central nervous system; it may also be a distinct nosographic entity. We identified nine patients in which progressive dysarthria remained the sole neurological sign for at least 2 years after onset. At least a year after hospital admission, the following diagnoses were made: two cases of corticobasal degeneration, one of frontotemporal dementia, one of primary progressive aphasia, one of motor neuron disease (MND)-dementia, one of ALS, and one of ALS-aphasia. In the remaining two patients progressive dysarthria remained the only neurological sign at latest examination. We conclude that in most cases progressive dysarthria is the presenting sign of an established neurodegenerative disease (generally degenerative dementia or motor neuron disease), although the possibility that progressive dysarthria is a distinct entity cannot be excluded. To clarify this issue, studies (probably multicenter) on more patients with longer clinical follow-up and pathological confirmation are required.

Primary progressive aphasia as the initial manifestation of corticobasal degeneration and unusual tauopathies

The clinical, neuroradiological, neuropathological and biochemical findings in four patients with primary progressive aphasia and tauopathy are described. The aphasic syndrome preceded by several years the appearance of other symptoms in every case. Asymmetrical apraxia with alien hand phenomenon occurred in one case. Frontotemporal symptoms occurred in three cases, but progressed to dramatic cognitive devastation in only one of these. Generalized dementia consistent with probable Alzheimer's disease (AD) developed with time in another. Cerebral computer tomography scans, magnetic resonance imaging and SPECT studies revealed marked asymmetries in one case, and showed nonspecific cerebral atrophy in the remaining ones. The neuropathological examination revealed typical corticobasal degeneration (CBD) in one case; CBD and AD in another; and atypical CBD, argyrophilic grain disease (AGD) and alpha-synucleinopathy consistent with Parkinson's disease in a third. Unique neuropathological findings were found in the remaining case. This was characterized by severe cerebral atrophy, marked neuronal loss in the cerebral cortex and abnormal tau deposition in neurons of the cerebral cortex, diencephalon and brain stem. Ballooned neurons, Pick bodies, generalized cortical neurofibrillary tangles and astrocytic plaques were absent. However, massive globular inclusions, containing phospho-tau, occurred in glial cells, mainly oligodendrocytes, in the white matter. Biochemical studies of frontal homogenates revealed four bands of 73/74, 68, 64 and 60 kDa of phosphorylated tau (using antibodies recognizing phospho-tau Thr181, Ser262 and Ser422) in the patient with AD and CBD, suggesting a predominant AD pattern in this case. Two bands of 68 and 64 kDa of phospho-tau were recovered in the sarkosyl-insoluble fraction in the other three cases. This pattern is similar to that found in CBD, progressive supranuclear palsy and AGD. Taken together, the present series further supports pure and combined CBD as causes of primary progressive aphasia, and they extend the hypothesis that primary progressive aphasia may be the initial symptom of distinct tauopathies.

Evidence of bilateral temporal lobe involvement in primary progressive aphasia: a SPECT study

Primary progressive aphasia (PPA) is rare. Only limited series have been reported with SPECT or PET. Moreover, in the majority of studies, the left-to-right asymmetry ratio was used, leading to difficulties in right hemisphere analyzes.

METHODS

Twenty-nine patients with clinical criteria of PPA (Mesulam and Weintraub) were included and compared with 12 control subjects. Complete language examination was performed in all patients. SPECT was performed on a double-head gamma camera after intravenous injection of hexamethylpropyleneamine oxime (22 patients and 12 control subjects) or ethylcysteinate dimer (7 patients). Nineteen regions of interest (ROIs) were drawn on each hemisphere in all patients using the Talairach atlas. The perfusion index (PI = cortex-to-cerebellum ratio) was calculated for each ROI. Atrophy was quantified on MRI by consensus of 3 observers in 16 cortical ROIs. ANOVAs were used to compare the PI between (a). patients and control subjects, (b). patients with (n = 15) or without (n = 14) lexicosemantic abnormalities (LS+ vs. LS-) and patients with (n = 19) or without (n = 10) arthric disorders (A+ vs. A-), and (c). patients with or without atrophy.

RESULTS

In the 29 patients, the PI was significantly lower in the left temporopolar, left lateral temporal, left Wernicke, left parietal, and right lateral temporal cortex when compared with control subjects (P < 0.001). In LS+ patients versus control subjects, the PI significantly decreased in the left temporal cortex (lateral temporal; medial temporal; temporopolar; Wernicke), left Broca, left parietal, and right lateral temporal cortex (P < 0.001). In addition, LS+ versus LS- comparison showed a significant decrease in the left lateral, left medial temporal, and left Broca cortex (P < 0.001). In comparison with control subjects, the PI was not significantly different in A+ patients, whereas in A- patients the PI was significantly decreased in the left and right lateral temporal cortex, left Wernicke, and left parietal cortex. Moreover, the PI significantly decreased in the left lateral temporal region in A+ patients compared with A- patients. Finally, in patients without atrophy, the PI significantly decreased in the right and left lateral temporal cortex and the left parietal cortex (P < 0.01).

CONCLUSION

Our study demonstrates that right-handed patients with PPA present a decreased perfusion in the bilateral temporal cortex. Moreover, in these regions, morphologic abnormalities are preceded by perfusion abnormalities. Finally, our results show that large left temporal dysfunction occurs in patients with LS disorders.

Progressive supranuclear palsy presenting with primary progressive aphasia--clinicopathological report of an autopsy case

We report a Japanese autopsy case of progressive supranuclear palsy (PSP). The male patient was 74 years old at the time of death. At age 64, he developed non-fluent aphasia that progressed slowly over 8 years, eventually associated with behavioral abnormality, postural instability, and dysphagia at 2 years prior to his death. Magnetic resonance imaging of the brain at age 73 demonstrated marked atrophy of the frontal lobes, particularly on the left side. Neuropathological examination revealed the typical pathology of PSP: loss of neurons, gliosis, occurrence of neurofibrillary tangles, oligodendroglial coiled bodies, and tuft-shaped astrocytes in the frontal cortex, associated with argyrophilic threads in the underlying white matter, in the basal ganglia, including the thalamus, globus pallidus, and subthalamic nucleus, and in the brainstem nuclei, including the substantia nigra, pontine nucleus, and inferior olivary nucleus. No astrocytic plaques or ballooned neurons were observed. Protein analysis revealed accumulation of hyperphosphorylated tau of 68 and 64 kDa consisting of the four repeat tau isoforms. We conclude that the present case represented PSP with an 8-year history of primary progressive aphasia (PPA). Although focal cortical symptoms in PSP are rare or absent, we should keep in mind the possibility of atypical PSP in which cortical pathology is predominant, particularly in the frontal lobe, and could result in PPA.

Modality-specific deterioration in naming verbs in nonfluent primary progressive aphasia

A longitudinal study of oral and written naming and comprehension of nouns and verbs in an individual (M. M. L.) with nonfluent primary progressive aphasia (PPA) is reported. M. M. L. showed progressive deterioration of oral naming of verbs well before deterioration of written naming of verbs and before deterioration of oral or written naming of nouns. Her comprehension of both nouns and verbs remained intact, at least relative to oral naming of verbs. Her performance is compared to that of two other individuals with nonfluent PPA, who were tested at two time points. These patients showed similar patterns with respect to grammatical word class (verbs more impaired than nouns) and modality (spoken production more impaired than written production), but somewhat different courses of deterioration. The modality-specific nature of the observed verb production deficits rules out a semantic locus for the grammatical class effects. The results provide a new source of evidence for the hypothesis that there are distinct neural mechanisms for accessing lexical representations of nouns and verbs in language production.

When traditional care falls short. Caring for people with atypical presentations of cortical dementia

1 People with chronic dementias receive care and support with programs designed for people with Alzheimer's disease, meaning a significant minority of patients will not benefit as a result of atypical or unusual presentations of cortical decline. 2 When patients have atypical presentations of dementia, nurses must recognize the unusual symptoms, assess care needs, and develop appropriate management strategies. 3 For patients with chronic dementia, individualized care planning includes knowledge of: 1) the patient's culture; 2) their past habits, activities, and preferences; 3) their remaining abilities; 4) the regions of the brain affected, histopathology, and size of the affected area; 5) the usual trajectory for the disease type; and 6) external demands. 4 Conducting research on assessment and care of people with atypical presentations of dementia is very difficult because of their rare nature and lack of recognition by health practitioners who may diagnose the patients with Alzheimer's disease.

Alzheimer disease and nonfluent progressive aphasia

OBJECTIVE

To describe a patient with pathologically proven Alzheimer disease (AD) who presented with a non-fluent progressive aphasic syndrome.

DESIGN

Longitudinal neuropsychological assessment, structural (magnetic resonance imaging) and functional (single photon emission computed tomography) imaging, and postmortem brain examination.

SETTING

Memory and cognitive disorders clinic in a tertiary referral hospital.

PATIENT

A 66-year-old man presented with a 5-year history of progressive nonfluent aphasia characterized by marked deficits in phonology and syntax with preservation of everyday abilities. His condition deteriorated rapidly and he died suddenly of a myocardial infarction 12 months later.

RESULTS

Neuropsychological testing revealed mild global intellectual impairment with marked impairment of auditory verbal short-term memory, syntactic, and phonological abilities. His naming errors were predominantly phonological paraphasias. Magnetic resonance imaging scans showed left perisylvian atrophy and results of a Tc 99m hexamethyl-propyleneamine-oxime single photon emission computed tomographic scan were normal. Postmortem pathological examination revealed typical AD pathological features with atypical distribution, involving predominantly perisylvian language areas, but sparing the medial temporal lobe.

CONCLUSIONS

The language deficits in AD, which have received considerable attention, are thought to involve predominantly lexicosemantic processes. When AD presents as a relatively isolated language disturbance, the aphasia is usually of the fluent anomic type. To our knowledge, our patient represents the first fully documented case of progressive nonfluent aphasia with pathologically verified AD.