A case of primary progressive aphasia. A 14-year follow-up study with neuropathological findings.

Primary progressive aphasia has been clinically defined as a progressive language deficit leading to the dissolution of almost all language functions with relative preservation of other cognitive functions until late in the course of the disease. Two types of language impairment have been described for primary progressive aphasia, which differ with respect to the degree of fluency of spontaneous speech. Whereas some authors have emphasized non-fluency as a defining characteristic of primary progressive aphasia, others have proposed that phonemic rather than semantic paraphasias in naming, both in the fluent and the non-fluent subtype, should be used as a criterion to distinguish primary progressive aphasia from slowly progressive aphasia in other forms of degenerative brain disease. Patients with fluent speech and semantic dementia, as typically seen in Alzheimer's disease, produce semantic paraphasias and circumlocutions rather than phonemic errors in naming. This paper reports the long-term follow-up of a patient with fluent aphasic speech, whose language profile over a decade was similar to that of patients with semantic dementia. Neuropathological examination revealed no evidence of Alzheimer's disease. Pick's disease or Pick variant, but showed spongiform changes of cortical layers (II and III) in temporal and, less severely, in frontal gyri. The present case indicates that semantic dementia is not a reliable indicator of probable Alzheimer's disease and supports the notion that there are different subtypes of primary progressive aphasia which cannot be defined by fluency or by the presence of phonemic paraphasia. Progress in identifying the neuropathological correlates of these subtypes in cases with lobar atrophy and spongiform changes should be expected from hereditary variants of progressive disorder.

Morphological processing in Italian agrammatic speakers: eight experiments in lexical morphology.

Agrammatic speech production has often been characterized as amorphology. This study of two Italian agrammatic patients shows that, with respect to inflectional morphology of simple and derived nouns, the morphological features of gender and number are almost fully preserved for one patient (MG) and only mildly disturbed in the other patient (DR). Like inflection, the use of derivational suffixation as a means of word-building is only mildly disturbed in both patients. However, they show a severe disturbance with respect to inflectional morphology of lexical compounds, which requires syntactic analysis at the word level. Moreover, they are severely impaired in the choice of the function word for the construction of prepositional compounds, syntactically generated phrases which have the status of a word. Apart from such syntax-dependent morphological and word-building operations, neither inflectional nor derivational morphology are seriously disturbed in our patients. The apparent amorphology in their spontaneous speech can thus not be explained by a disorder of morphological representations in the lexicon system perse. In another study (De Bleser and Luzzatti, 1994) we were able to show that the patients had severe problems with the implementation of morphology in specific syntactic contexts, thus pointing to a problem in morphosyntactic rather than morpholexical processing as a factor contributing to agrammatic speech production.

Impaired picture recognition with preserved object naming and reading.

A case study is reported on a left posterior cerebrovascular accident involving the infracalcarine cortex. The patient (HG) exhibited a marked color anomia and picture naming deficit (photograph anomia) without alexia. However, objects were named successfully from either visual or tactile inspection. Despite successful object categorization in several tasks, it is argued that HG's picture naming deficit is dependent on a disorder of recognition (access to the stored structural descriptions for objects). A similar functional impairment can account for HG's impaired color naming. The site of HG's cortical damage implies that recognition disorders can result from a unilateral left-sided lesion.

Morphological processing in Italian agrammatic speakers syntactic implementation of inflectional morphology.

Most current linguistic and psycholinguistic characterizations of agrammatic production start from the observation that in spontaneous speech inflectional suffixes are either dropped or substituted by default forms, depending on the morphological structure of the language. So far, little experimental evidence has entered theory construction. In this paper, elicited data of two Italian patients with agrammatic speech are presented. The tasks involved the production of a past participle suffix in different sentence contexts. In Italian, the past participle has to agree in gender and number with the grammatical features of an antecedent noun, pronoun, or empty element. It is shown that both patients mastered the general principles of the agreement rule, and that they could produce correct inflectional suffixes in several tasks. Furthermore, the point of breakdown in their performance was syntactic rather than morphological, namely, when there were no overt morphological cues for the identification of the thematic roles in the sentence. These data cannot be accounted for by theories formulated in terms of the syntactic or postsyntactic deletion of suffixes or the functional elements underlying their realization. At least for the patients in this study, morphological substitutions arose as a result of an impairment in the syntactic processing of content words rather than functors.

Visual agnosia: a case of reduced attentional "spotlight"?

A case study is presented of a patient with presenile dementia, for whom the dominant clinical feature from onset was a visual agnosia. The characteristics of the patient's visual agnosia were investigated in light of her apparent use of a "feature-by-feature" strategy to identify objects. Results from various tasks showed that the patient was unable to use global shape information or other grossly defined property cues characteristic of a "wide angle" attentional processing stage (Treisman, 1988) in object recognition. The patient appeared instead to rely on 'parts' or identifying features of the objects for object recognition. The patient showed significant improvement when the size of the drawing was reduced in size, thus suggesting that the disorder may be functionally localized to a reduction of the patient's attentional "spotlight".

Morphosyntactic processing in German agrammatism: a replication and revision of von Stockert/Bader (1976).

This paper reports the results of a revised replication of the von Stockert/Bader constituent ordering study (1976) with German agrammatics. Part 1 describes why such a replication was necessary. In part 2, the original study is summarized and the weaknesses are identified which caused a revision. Part 3 reports the replication study with 10 German agrammatics. The findings of the original study with respect to Broca's aphasics could not be replicated: instead of an almost total loss of morphosyntactic sensitivity, there was almost total preservation. Part 4 eliminates the possibility of a population artefact by reporting on the performance of 3 patients with global aphasia. Part 5 integrates the results of this study within a larger framework of syntax and inflectional morphology in (German) agrammatism.

Analysis of prosody in the spontaneous speech of patients with CV-recurring utterances.

We report a study on 9 patients with global aphasia whose language production was restricted to chains of one and the same recurring CV syllable. Length of utterance was determined by the number of syllables between two pauses and major length types were used for pitch analysis. By means of a tonetic method the pitch level of syllables was transcribed so that pitch variations could be established. Our findings contradicted the clinical impression that these patients can convey communicative intentions by means of a variety of fluently produced intonation contours. Even though all patients had a considerable inventory of length types they predominantly used only one or two of them. Pitch types were found to be similarly stereotypical. As an explanation for the fluently produced CV utterances with stereotypical length and pitch, the assumption of iterative motor mechanisms underlying CV speech production was rejected in favour of preserved automatic speech processing and abolished controlled processing.

Neurolinguistic status and localization of lesion in aphasic patients with exclusively consonant-vowel recurring utterances.

Eight patients are presented whose speech production consisted exclusively of one and the same recurring consonant-vowel (CV) syllable, similar to Broca's first patient Leborgne ('Tan-tan'). Their neurolinguistic, aphasiological and localizational status was examined and compared with 32 patients with standard global aphasia and 15 with Broca's aphasia. Patients with exclusively CV speech production represent a variety of global aphasia, characterized by fluency of output and the preservation of some prosody. Localization of the CT lesion did not distinguish between the nonstandard fluent global aphasics described here and the well-known standard nonfluent global aphasics. The individual lesions in both subgroups show great variability in size and localization, which is not recognized in the usual cumulative representations of CT lesions.

Stereographic reconstruction of human brain CT series.

A relatively simple method for the three-dimensional reconstruction of brain contours from a series of CT scans is presented. A procedure is described for storing the structural information obtained from the CT series and for organizing and displaying the data. Furthermore, it is shown how additional features such as standardized artery information taken from an atlas can be superimposed on the spatially reconstructed brain model. It is proposed that three-dimensional representations in the form of computed stereo pairs are quite suitable for morphological documentation of specific neuropsychological issues, such as the localization of aphasic syndromes.

A refined method to relate morphological and functional aspects of aphasia.

A method is described to relate brain morphology and neuropsychological disturbances such as aphasia. By mapping lesions with computerized tomography onto a grid model of five brain slices, it is possible to compare aphasiological information and lesion site by data processing, allowing the quantitative and qualitative manipulation of a large number of data. The soundness of the method is investigated in a pilot study on the localization of aphasic disturbances. Data processing was performed on a preliminary group of 70 patients with different aphasic syndromes (Broca, Wernicke, and global aphasics with and without recurring utterances). The results confirmed the findings of older studies, with the typical locus of Wernicke's aphasia being Wernicke's area. In conformity to more recent studies, the main lesion for Broca aphasics was found to be in the insular cortex, with a relatively important participation of the frontal white matter. The implications of this refined method for more vigorous aphasiological and neuropsychological research are briefly indicated.