Biomedical subjects

Naida L Graham

Publications and source records attributed to Naida L Graham.

4 recordsLinked to original sources

PubMed2004

When more yields less: speaking and writing deficits in nonfluent progressive aphasia.

Fourteen patients with nonfluent progressive aphasia (NFPA) performed a picture description task in both spoken- and written-output conditions, as well as tests of confrontation naming, spelling to dictation and reading aloud of single words and text. Relative to controls, the patients' spoken and written picture descriptions were reduced in length, speed and amount of information. Of particular interest, and accounting for the first part of the article's title, was a pervasive pattern of poorer spoken and written output associated with the requirement to produce more; this was true when 'more' meant either (a) longer vs. shorter single words or (b) connected language vs. single words. Deficits in spoken and written naming were largely parallel and modality-specific output impairments (such as dysarthria in speech or letter-formation problems in writing) seemed to account for the minority of cases who exhibited a discrepancy. Most patients showed no evidence of agrammatism or reduced verb production in their speech, which typically had normal proportions of content and function words as well as nouns and verbs. By contrast, some degree of telegraphic output was observed in the written narratives of a number of patients. Our results argue against several candidates for the main functional locus of impairment in NFPA, but it is likely that deficits in grammatical processing, working memory, planning/executive skills, speech motor abilities and phonological processing all play a role.

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PubMed2003

Language function and dysfunction in corticobasal degeneration.

OBJECTIVE: S: The authors assessed language functioning in corticobasal degeneration (CBD), an area that has received little systematic study. Aphasia has been reported occasionally, and the authors hypothesized that appropriate assessments would reveal at least mild language impairment, particularly affecting phonologic (sound-based) processing, even in cases without frank aphasia. METHODS: A series of 10 unselected patients with CBD (one with pathologic confirmation) were administered neuropsychological tests assessing the following aspects of cognitive functioning: verbal fluency, naming, reading, oral spelling, auditory-verbal short-term memory, phoneme blending and segmentation, visuospatial skills, and semantic memory. RESULTS: Phonologic and spelling impairments were prevalent, even in nonaphasic patients. The prevalence of visuospatial, constructional, and frontal impairments, demonstrated in previous research, was also replicated. A minority of patients had deficits in semantic memory, naming, and reading, but the impairments were usually mild. CONCLUSIONS: The authors found phonologic impairment to be a typical feature of CBD. There is substantial overlap between progressive nonfluent aphasia and CBD, and the linguistic impairment can be thought of as a continuum, with mild phonologic impairment at one end and severe aphasia at the other.

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PubMed2003

Progressive non-fluent aphasia is associated with hypometabolism centred on the left anterior insula.

Progressive non-fluent aphasia (PNFA) is a syndrome in which patients lose the ability to communicate fluently in the context of relative preservation of single word comprehension and non-linguistic cognitive abilities. Neuroimaging in case studies with PNFA has failed to identify a consistent neural substrate for the language disorder. In this study of a group of patients (n=10) whose presenting complaint was progressive dysfluency, resting cerebral metabolism was measured using [18F]fluorodeoxyglucose-PET and analysed with the technique of statistical parametric mapping (SPM). Regional atrophy was assessed with voxel-based morphometry (VBM). Seven patients had a 'pure' PNFA syndrome, while the remaining three had additional features of a more pervasive dementia. Compared with controls, the patients showed hypometabolism in several regions that, most notably, included the left anterior insula/frontal opercular region. The VBM analysis revealed only one small area of atrophy in the left peri-Sylvian region. Analysis of the pure PNFA cases (n=7) relative to controls yielded qualitatively similar results to those of the whole group, suggesting that these cases were also at risk of a more generalized dementia, a finding borne out in subsequent follow-up of two cases to date. The PNFA group was then compared with a group with Alzheimer's disease (n=10) whose clinical profile did not include non-fluent aphasic features. In this analysis, the only persisting hypometabolic region was that centred over the left anterior insula. VBM did not identify any regional differences in atrophy between PNFA and Alzheimer's disease. In the light of current theories of fluent language production, the findings offer anatomical evidence that the breakdown in fluency is due to a motor articulatory planning deficit (speech apraxia) combined with a variable degree of agrammatism.

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PubMed2003

Corticobasal degeneration as a cognitive disorder.

The presence of cognitive impairment in corticobasal degeneration (CBD) is now widely recognised. Our review of the literature reveals that, although the pattern and severity of neuropsychological impairments can be highly variable across patients, several general trends can be identified. The most characteristic impairments are limb apraxia (usually ideomotor), constructional and visuospatial difficulties, acalculia, frontal dysfunction, and nonfluent aphasia. The limb apraxia is associated with deficits in drawing, copying, and handwriting, but there is emerging evidence that the problems with handwriting are not due exclusively to the apraxia. The findings with respect to episodic memory are more variable, but when there is impairment in this area, it tends to be milder than that seen in Alzheimer's disease. Semantic memory functioning appears relatively preserved but has been poorly studied. Problems with speech are common, and may be due to dysarthria or buccofacial apraxia. Aphasia, although initially considered rare, is in fact a common accompaniment of CBD, may be the presenting feature, and is typically nonfluent in type. More systematic investigation of the clinical and neuropathological overlap between progressive nonfluent aphasia (generally considered to be a form of frontotemporal dementia) and CBD is needed.

Aphasia↗