Primary Progressive Aphasia Syndromes Research Articles

Different patterns of Mini Mental Status Examination responses in primary progressive aphasia and Alzheimer's disease

Primary progressive aphasia (PPA) syndrome is frequently misdiagnosed--particularly in favour of Alzheimer's disease (AD). Misdiagnosis is related to the heterogeneity of language disorders at onset, variability in the rate of clinical progression and the low prevalence of PPA syndrome, compared with AD. The aim of this study was to determine whether a patient's first Mini Mental Status Examination (MMSE) might provide insight into differentiating between PPA and AD. We compared item scores for the first, complete MMSE in consecutive patients with PPA versus matched patients with AD. Word recall and constructional praxis were significantly better in patients subsequently diagnosed as suffering from PPA. Patients with AD performed significantly better in terms of word registration, object naming, repetition and verbal direction. Our findings indicate that the various MMSE item scores may be helpful in differentiating PPA and AD in the first few years of the disease.

Familial primary progressive aphasia.

Primary progressive aphasia (PPA) is a neurodegenerative disease presenting with isolated, progressive, language dysfunction. After at least 2 years, dementia may develop, but the aphasia predominates. Few families with hereditary PPA have been reported; some have autosomal dominance. A chromosome 17 mutation in tau exon 13 has been found in one family, and a few have linkage to chromosome 17. However, early appearance of prominent memory, behavior, and motor impairments differentiates these patients from typical PPA. The objective was to report clinical features, pathology, and genetic analysis of a family with typical PPA. We report three siblings with the typical clinical syndrome of PPA. Each presented with word-finding difficulties and early anomia. Ages at onset were 60, 61, and 65 years. Aphasia was the only symptom for at least 2 years. A nonaffected brother is 75 years of age. Family history review found no other affected relatives. Neuropathology in one patient demonstrated "dementia lacking distinctive histopathology" with ubiquitin-positive cortical neurons. DNA analysis of the proband did not detect any known mutation in tau exons 1-5, 7, or 9-13. To our knowledge, this is the first family presenting with hereditary aphasia in which typical PPA occurs in all affected members.

Superiority of Functional over Structural Neuroimaging in the Diagnosis of Primary Progressive Aphasia

For a 68‐year‐old man with the syndrome of primary progressive aphasia, functional brain imaging techniques (single‐photon emission computed tomography and topographic electroencephalographic mapping) proved superior to anatomical imaging techniques (magnetic resonance imaging and computed tomography) in delineating the left temporal lobe abnormality.

Primary Progressive Aphasia

Four patients with the clinical syndrome of primary progressive aphasia and a nonfluent aphasia profile were followed up over a period of 3 to 5 years. Extensive neuropsychological data for three patients revealed a progressive, quantitative decline of language with relative stability of memory, visuospatial skills, and reasoning. Comportment and most activities of daily living were preserved even when speech was unintelligible. Although several aphasia types may be associated with primary progressive aphasia, a nonfluent aphasia profile and phonemic paraphasic errors are most useful in differentiating it from the much more common clinical syndrome, "probable Alzheimer's disease." The clinicopathological correlates of probable Alzheimer's disease differ from those associated with primary progressive aphasia. Therefore, the clinical distinction between the two syndromes may be important for predicting the underlying pathophysiologic changes during the life of the patient.

Memory impairments following restricted thalamic lesions in monkeys

The neuropsychological features of the primary progressive aphasia (PPA) syndromes continue to be defined. Here we describe a detailed neuropsychological case study of a patient with a mutation in the progranulin (GRN) gene who presented with progressive word-finding difficulty. Key neuropsychological features in this case included gravely impoverished propositional speech with anomia and prolonged word-finding pauses, impaired speech repetition most marked for sentences, and severely impaired verbal (with preserved spatial) short-term memory. There was a dissociated profile of performance on semantic processing tasks: visual semantic processing was intact, while within the verbal domain, verb comprehension was impaired and processing of nouns was intact on tasks requiring direct semantic processing but impaired on tasks requiring associative or inferential processing. Brain MRI showed asymmetric left cerebral atrophy particularly affecting the temporo-parietal junction, supero-lateral temporal and inferior frontal lobes. This case most closely resembles the PPA syndrome known as the logopenic/phonological aphasia variant (LPA) however there were also deficits of grammar and speech repetition suggesting an overlap with the progressive non-fluent aphasia (agrammatic) variant (PNFA). Certain prominent features of this case (in particular, the profile of semantic impairment) have not been emphasised in previous descriptions of LPA or PNFA, suggesting that GRN may cause an overlapping PPA syndrome but with a distinctive cognitive profile. This neuropsychological evidence suggests that GRN-PPA may result from damage involving the temporo-parietal junction and its functional connections in both the dorsal and ventral language networks, with implications for our understanding of language network pathophysiology.