Brain Advance Access originally published online on August 20, 2009
Brain 2009 132(10):2734-2746; doi:10.1093/brain/awp207
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Making sense of progressive non-fluent aphasia: an analysis of conversational speech
1 Royal Preston Hospital, Department of Neurology, Sharoe Green Lane North, Fulwood, Preston, Lancashire PR2 9HT, UK 2 Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Manchester, UK 3 Prince of Wales Medical Research Institute, Sydney, New South Wales, Australia 4 MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
Correspondence to: Jonathan A Knibb, Department of Neurology, Royal Preston Hospital, Sharoe Green Lane North, Fulwood, Preston, Lancashire PR2 9HT, UK E-mail: jonathan_knibb{at}hotmail.com
The speech of patients with progressive non-fluent aphasia (PNFA) has often been described clinically, but these descriptions lack support from quantitative data. The clinical classification of the progressive aphasic syndromes is also debated. This study selected 15 patients with progressive aphasia on broad criteria, excluding only those with clear semantic dementia. It aimed to provide a detailed quantitative description of their conversational speech, along with cognitive testing and visual rating of structural brain imaging, and to examine which, if any features were consistently present throughout the group; as well as looking for sub-syndromic associations between these features. A consistent increase in grammatical and speech sound errors and a simplification of spoken syntax relative to age-matched controls were observed, though telegraphic speech was rare; slow speech was common but not universal. Almost all patients showed impairments in picture naming, syntactic comprehension and executive function. The degree to which speech was affected was independent of the severity of the other cognitive deficits. A partial dissociation was also observed between slow speech with simplified grammar on the one hand, and grammatical and speech sound errors on the other. Overlap between these sets of impairments was however, the rule rather than the exception, producing continuous variation within a single consistent syndrome. The distribution of atrophy was remarkably variable, with frontal, temporal and medial temporal areas affected, either symmetrically or asymmetrically. The study suggests that PNFA is a coherent, well-defined syndrome and that varieties such as logopaenic progressive aphasia and progressive apraxia of speech may be seen as points in a space of continuous variation within progressive non-fluent aphasia.
Key Words: progressive aphasia; frontotemporal dementia; language; cortical atrophy; neuropsychology
Abbreviations: FTLD, fronto-temporal lobar degeneration; LPA, logopaenic progressive aphasia; MDE, metadata extraction; MRI, magnetic resonance imaging; PNFA, progressive non-fluent aphasia; SD, semantic dementia; TROG, Test for the Reception of Grammar; VOSP-PD, Visual Object and Space Perception battery, Position Discrimination subtest; WCST, Wisconsin Card Sort Test; WPMT, word-picture matching test
Received April 17, 2009. Revised July 6, 2009. Accepted July 7, 2009.