Authors:

Knibb, J.A., Xuereb, J.H., PATTERSON, K. & HODGES, J.R.

Reference:

Year of publication:

2006

CBU number:

6152

Abstract:

The clinical and neuropathological categorisation of patients presenting with progressive aphasia is an area of controversy. This study aimed to characterise a large group of progressive aphasic patients from a single centre (n = 38), first clinically by casenote review, and then pathologically. Hierarchical cluster analysis of the cases according to their clinical language deficits was used to establish an unbiased, data-driven classification. This analysis revealed two groups of cases corresponding to the syndromes of progressive non-fluent aphasia (n = 23) and semantic dementia (n = 15). Post-mortem analysis revealed a majority in both groups of pathologies from the spectrum of FTLD: the most frequent were non-AD tauopathy in the non-fluent cases (10 of 23) and FTLD 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 about one-third of each group (overall 12 of 38), though often with an atypical neuroanatomical distribution. Progressive aphasia is best seen as a composite of two conditions, on both clinical and pathological levels: progressive non-fluent aphasia and semantic dementia.