Primary progressive aphasia

Primary progressive aphasia (PPA) is a focal dementia characterized by an isolated and gradual dissolution of language function. The disease starts with word-finding disturbances (anomia) and frequently proceeds to impair the grammatical structure (syntax) and comprehension (semantics) of language. The speech output in PPA can be fluent or nonfluent. Memory, visual processing, and personality remain relatively well-preserved until the advanced stages and help to distiguish PPA from frontal lobe dementia and the typical forms of Alzheimer's disease. The term "semantic dementia" was originally introduced to designate a different group of patients with a combination of verbal and visual processing deficits. In practice, however, this diagnosis is also being used in a variant sense to denote a subtype of PPA with fluent speech and impaired comprehension, even in the absence of visual processing deficits. Insofar as the diagnosis of semantic dementia can have these two different meanings, it is important to specify whether it is being used in the original sense or to denote a subtype of PPA. Structural and physiological neuroimaging confirms the selective predilection of PPA for the left hemisphere, especially for its language-related cortices. A few patients with PPA display the neuropathological markers of Alzheimer's disease, but in an unusual distribution. The majority of the autopsies in PPA have shown either Pick's disease or lobar atrophy without distinctive histopathology. The suggestion has been made that PPA and frontal lobe dementia constitute phenotypical variations of a unitary disease process within the "Pick-lobar atrophy" spectrum. Recent advances in chromosome 17-linked dementias justify a rigorous search for tau polymorphisms and tauopathy in sporadic PPA. An informed approach to this syndrome will increase the effectiveness with which clinicians can address the unique challenges associated with the diagnosis and care of PPA.     

Primary progressive aphasia: a review

This review summarizes clinical and imaging features associated with primary progressive aphasia (PPA). We investigate the hypothesis that these patients can be divided into subgroups of progressive non-fluent aphasia (PNFA) and semantic dementia (SD), based on their linguistic profiles and related imaging studies, and examine whether each of these major subgroups can be further subdivided. We focus on several critical features within each progressive aphasic subgroup. In PNFA, we examine agrammatism, phonologic disorder, and impaired verb processing to determine whether this syndrome is related to a modality-specific impairment in word formation and articulation, or a conceptual deficit that interferes with grammatical processing. In SD, we examine impaired semantic memory, limited remote memory, and anomia to assess whether this syndrome is due to a modality-neutral interruption of semantic memory, or the degradation of various material-specific representations of object features and words. We conclude that there is sufficiently consistent and converging evidence from clinical and imaging studies to support the claim that PNFA and SD are distinct subgroups of PPA. However, there does not appear to be sufficient evidence at this point to support further discrimination within these progressive aphasic subgroups. Testing hypotheses about finer-grained syndromes such as progressive dysarthria or progressive anomia has important consequences for improving our understanding of language organization and the neural basis for language.     

Clinical and pathological characterization of progressive aphasia

OBJECTIVE: The clinical and neuropathological categorization of patients presenting with progressive aphasia is an area of controversy. This study aimed to characterize a large group of progressive aphasic patients from a single center (n = 38), first clinically by case note review, and then pathologically. METHODS: Hierarchical cluster analysis of the cases according to their clinical language deficits was used to establish an unbiased, data-driven classification. RESULTS: This analysis revealed two groups of cases corresponding to the syndromes of progressive nonfluent aphasia (n = 23) and semantic dementia (n = 15). Postmortem analysis showed a majority in both groups of pathologies from the spectrum of frontotemporal lobar degeneration: the most frequent were non-Alzheimer's disease (AD) tauopathy in the nonfluent cases (10 of 23) and frontotemporal lobar degeneration with ubiquitin-positive, tau-negative inclusions in the fluent cases (8 of 15). Despite rigorous exclusion of cases with clinically significant memory deficits or other cognitive impairments, the pathology of AD was present in approximately one third of each group (overall 12 of 38), although often with an atypical neuroanatomical distribution. INTERPRETATION: Progressive aphasia is best seen as a composite of two conditions, on both clinical and pathological levels: progressive nonfluent aphasia and semantic dementia.     

Primary progressive aphasia: a comparative study of progressive nonfluent aphasia and semantic dementia

Primary progressive aphasia (PPA), a degenerative disorder, is often misdiagnosed as Alzheimer's disease. Its subtypes, semantic dementia (SD), and progressive nonfluent aphasia (PNFA), are often difficult to differentiate from each other. Our objective was to highlight the differences in the language profiles of patients with SD and PNFA. To bring out these differences, we report two patients with PPA, one with SD and the other with PNFA. They were administered the Western aphasia battery (WAB) and a semantic battery, which assesses semantic memory. The profiles of language impairment on the WAB indicated that the patient with PNFA had syntactic errors in expressive speech but relatively preserved semantics and comprehension, whereas the patient with SD had preserved syntax but made semantic errors in expressive speech, and had impaired comprehension. There were differences in their performance on the semantic battery too. The patient with SD made relatively less errors on confrontation naming, although on the pointing task he failed to point to those line drawings, which he was unable to name on confrontation. In contrast, the finding of the PNFA patient was the reverse of this. Supplementing conventional neuropsychological tests with formal tests for assessment of language functions is useful in the early diagnosis of PPA. The performance of PPA patients on a detailed assessment of language that includes use of formal tests such as the semantic battery helps to differentiate PNFA from SD.     

原发性进行性失语一例临床分析

目的 原发性进行性失语（PPA）是一种少见的中枢神经系统变性疾病，国内罕见报道。现报道1例，以提高临床医生对该病的认识。方法 采用韦氏一表、认知能力筛选检查、积木测验、数字广度测验和社会功能问卷等全套神经心理学量表方法，检查和描述了PPA的临床和神经心理学特征；并进行了MRI和PET影像学检查。结果 病人除有单纯性命名性失语外，不伴有其他类型的失语与智能损害及神经系统体征；MRI和PET检查均发现左颞叶明显萎缩。结论 PPA以缓慢进行性失语而不伴有认知功能障碍和神经系统体征为特点，优势半球局灶性额、颞叶病变有诊断意义。     

Primary progressive aphasia: a case report

We report a 69-year-old male patient whose motor aphasia started at the age of 61. The language disability remained isolated and progressed over a period of eight years without any additional cognitive deficits. Computed tomography (CT) and magnetic resonance imaging (MRI) showed moderate cortical atrophy with frontal dominance. Single photon emission tomography (SPECT) showed hypoperfusion in the frontotemporoparietal region, positron emission tomography (PET) demonstrated a global cortical reduction of glucose utilization with a lesser decrement in the occipital lobes. The clinical symptoms and the neuropsychological findings fit the diagnosis of primary progressive aphasia.     

Primary progressive aphasia and Pick complex

Ten autopsied patients from a prospectively followed, clinically defined, neuropsychologically and radiologically documented cohort with primary progressive aphasia were histologically characterized. All were variants of frontotemporal degeneration (Pick complex): Pick body dementia, n=3, corticobasals degeneration (CBD), n=4, and tau and synuclein negative ubiquitinated inclusions of the motor neuron disease type, n=3. All shared superficial cortical spongiosis, neuronal loss, and gliosis. Although most patients had fluent anomic aphasia at onset, all progressed to a nonfluent or mute state. Comprehension, episodic memory, and activities of daily living were initially preserved. Three cases with Pick body dementia had verbal apraxia and stuttering at onset. Two of the patients with CBD pathology were older than the average primary progressive aphasia (PPA). All patients developed secondary syndromes either of frontotemporal dementia (FTD) and/or extrapyramidal-apraxic manifestations (CBD). By the time autopsy was obtained, the pathology appeared outside the language areas. Progressive aphasias secondary to Alzheimer's disease (AD) were excluded on the basis of early loss of memory and comprehension.Rather than the previously emphasized histological heterogeneity, clinically probable PPA has a predictive value of a group of related pathologies, collectively named frontotemporal degeneration, or Pick complex. This series of autopsied cases provides evidence for the clinical and pathological overlap of PPA with FTD and CBD, and contributes to the diagnostic and neuropsychological definition of PPA.     

Primary progressive aphasia with parkinsonism

A 65‐year‐old man presented with word‐finding difficulty and gait disturbance. His speech was nonfluent with word retrieval impairment and difficulties with sentence repetition. Other cognitive domains were intact initially. He developed asymmetrical bradykinesia, rigidity and a rest tremor. Over the following 8 years, his speech production impairment slowly deteriorated with the development of a motor speech disorder, anomia, impaired repetition of single words as well as sentences, and impaired comprehension of initially sentences then single words. His parkinsonian syndrome also deteriorated with limited response to levodopa. Serial brain MRI revealed progressive asymmetric perisylvian atrophy. He died after a disease duration of 12 years. The clinical syndrome is discussed by an expert, the pathology is described, and important clinical points from the case are highlighted. © 2013 Movement Disorder Society     

Primary progressive aphasia presenting as conduction aphasia.

We report a case of a woman with primary progressive aphasia (PPA) who presented with conduction aphasia. A 60-year-old, right-handed, Japanese female suffering from progressive aphasia had difficulty in repeating words and phrases. She displayed phonemic paraphasias but had preserved comprehension and had no cognitive or behavior disorder for more than 6 years after the onset of the condition. She was able to continue to work successfully and to perform all her normal daily activities. T1-weighted magnetic resonance imaging revealed minute dilatation of the left inferior horn and sulci in the left hemisphere, and positron emission tomography revealed mild hypometabolism in the left supramarginal gyrus and its surrounding areas. Therefore, she was diagnosed as suffering from PPA presenting as conduction aphasia. We believe that the progressive conduction aphasia of the patient belongs to one of the fluent forms of PPA, and the ability to continue normal work along with the clinical portrayal of preserved memory and cognition skills may be features of a form of PPA presenting as conduction aphasia.     

Primary progressive aphasia: PPA and the language network

Primary Progressive Aphasia (PPA) is a behaviorally focal dementia syndrome with deterioration of language functions but relative preservation of other cognitive domains for at least the first two years of disease. In this study, PPA patients with impaired word finding but intact comprehension of conversational speech and their matched control subjects were examined using voxel-based morphometry (VBM) and functional magnetic resonance imaging (fMRI). fMRI compared signal changes during phonological and semantic language tasks with those during a control task (matching letters). PPA patients showed longer reaction times and reduced accuracy versus controls on the language tasks, but no performance differences on the control task. VBM demonstrated reduced gray matter in left superior temporal and inferior parietal regions in the PPA group. However, these patients showed a normal pattern of activation within the classical language regions. In addition, PPA patients showed activations, not seen in normals, in fusiform gyrus, precentral gyrus, and intra-parietal sulcus. These activations were found to correlate negatively with measures of naming and task performance. The additional activations in PPA may therefore represent a compensatory spread of language-related neural activity or a failure to suppress activity in areas normally inhibited during language tasks.     

Primary progressive aphasia: analisys of 16 cases

Primary progressive aphasia (PPA) is an intriguing syndrome, showing some peculiar aspects that differentiate it from classical aphasic pictures caused by focal cerebral lesions or dementia. The slow and progressive deterioration of language occurring in these cases provides an interesting model to better understand the mechanisms involved in the linguistic process. We describe clinical and neuroimaging aspects found in 16 cases of PPA. Our patients underwent language and neuropsychological evaluation, magnetic resonance imaging (MRI) and single photon emission computerized tomography (SPECT). We observed a clear distinction in oral expression patterns; patients were classified as fluent and nonfluent. Anomia was the earliest and most evident symptom in both groups. Neuroimaging pointed to SPECT as a valuable instrument in guiding the differential diagnosis, as well as in making useful clinical and anatomical correlations. This report and a comparison to literature are an attempt to contribute to a better understanding of PPA.     

Primary progressive aphasia: a 25-year retrospective

The diagnosis of primary progressive aphasia (PPA) is made in any patient in whom a language impairment (aphasia), caused by a neurodegenerative disease (progressive), constitutes the most salient aspect of the clinical picture (primary). The language impairment can be fluent or nonfluent and may or may not interfere with word comprehension. Memory for recent events is relatively preserved although memory scores obtained in verbally mediated tests may be abnormal. Lesser changes in behavior and object recognition may be present but are not the leading factors that bring the patient to medical attention. This selective clinical pattern is most conspicuous in the initial stages of the disease. Progressive nonfluent aphasia and some types of semantic dementia can be considered subtypes of PPA. Initially brought to the attention of contemporary literature 25 years ago, PPA has recently witnessed substantial progress related to its neurolinguistic features, neuroanatomy, imaging, neuropathology, genetics, and risk factors.     

Primary progressive aphasia : a case report.

Primary progressive aphasia is due to focal left perisylvian degeneration and manifests with progressive decline in language function for two or more years. There is preservation of cognitive functions and activities of daily living continue to be normal. We report a case of progressive aphasia in a 65 year old lady.     

Primary progressive non-fluent aphasia: a case study

A case study of a 65 year old man is described with an eight-year history of progressive primary non-fluent aphasia accompanied by agrammatism, phonemic paraphasias and mild spelling dysgraphia. His naming ability, however, has remained at an exceptionally high level and there has been no evidence of impairment of word or sentence comprehension. Non-verbal skills and memory functions have also been preserved within the range of his very high premorbid level of abilities. Single photon emission computed tomography was consistent with bifrontal hypoperfusion. We argue that the selective language deficits in this patient are characteristic of dynamic aphasia and of other speech disturbances which are also known to be associated with left frontal lesions. The possible underlying pathology is discussed in the context of known degenerative disorders.     

Primary progressive aphasia with focal neuronal achromasia

We describe the clinical, radiologic, neuropsychological, and neuropathologic features of a 69-year-old man with a 3-year history of progressive transcortical expressive aphasia. Neuropsychological testing showed progressive dysfunction of expressive language. Neuropathologic examination demonstrated focal cortical degeneration involving the left superior frontal gyrus, with swollen achromasic neurons and no evidence of Alzheimer's disease, Pick's disease, Creutzfeldt-Jakob disease, Lewybody disease, or other dementing disorders. This case adds to the known heterogeneity of the underlying pathology of patients with primary progressive aphasia.     

Primary progressive aphasia in a bilingual woman

Multilingual aphasias are common because most people in the world know more than one language, but little is known of these syndromes except in patients who have had a stroke. We present a 76-year-old right-handed woman, fluent in English and Chinese, who developed anomia at age 70 and then progressed to aphasia. Functional neuroimaging disclosed mild left temporoparietal hypometabolism. Neurolinguistic testing was performed in both English and Chinese, representing a unique contribution to the literature. Results revealed conduction-like aphasia that was comparable in the two languages, although English was slightly better preserved. Primary progressive aphasia has disrupted 2 languages in a similar manner, suggesting their close neuroanatomic relationship in this case.