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Semantic dementia (SD) is a syndrome of progressive loss of semantic knowledge for objects and people. International criteria propose that SD be included in the frontotemporal lobar degeneration syndromes, with progressive non-fluent aphasia and frontotemporal dementia (FTD). However, several related syndromes have been defined that clinically and conceptually share both similarities and differences with SD: fluent progressive aphasia, progressive prosopagnosia, temporal variant of FTD. In order to establish a French consensus for the diagnosis and modalities of evaluation and follow-up of SD, a working group, composed of neurologists, neuropsychologists and speech-therapists, was established by the Groupe de réflexion sur les évaluations cognitives (GRECO). New criteria were elaborated, based on clinical, neuropsychological, and imaging data. They define typical and atypical forms of SD. A diagnosis of typical SD relies on an isolated and progressive loss of semantic knowledge, attested by a deficit of word comprehension and a deficit of objects and/or people identification, with imaging showing temporal atrophy and/or hypometabolism. SD is atypical if the deficit of semantic knowledge is present only within a single modality (verbal versus visual), or if non-semantic deficits (mild and not present at onset) and/or neurological signs, are associated with the semantic loss.

The Benton Visual Retention Test (BVRT) is a widely used test for the evaluation of visuospatial memory. Alternate forms and various types of administration are available. Whereas most of the formats are visuoconstructional tasks, the forms F and G involve visual recognition. There are several reasons to use multiple-choice formats when studying age-related memory changes. Its procedure involving immediate recognition of geometric designs allows assessment of visuospatial working memory--a memory system particularly vulnerable to aging. The administration is rapid--it can be completed in 5 min--and is easily standardized. The multiple-choice format, relative to the drawing-response formats, also has the advantage of eliminating the influence of visuomotor and manual dexterity problems common in the elderly. Another advantage is the possibility of referring to recent geriatric norms, which can help clinicians or researchers identify individuals with low scores and potentially at risk for dementia.

To assess the influence of age and other sociodemographical variables, depressive symptomatology and the occurrence of Alzheimer's disease (AD) on cube drawing, we examined the performance of 858 normal subjects and 17 incident AD patients in the PAQUID population-based study. Cube drawing was first performed on verbal command and, in case of failure, a model of a cube was given to the subjects to copy. Normal subjects had some difficulties in drawing a cube on verbal command, evidenced by 40% failure in the drawing-to-command condition, while only 17% still failed in the drawing-to-copy condition. Multivariate logistic regressions showed that age, gender, and educational level were associated with cube drawing failure in both conditions, but depressive symptomatology was only associated with persistent failure in the drawing-to-copy condition. Seventy-six point five percent of incident AD subjects failed in the drawing-to-command condition and 64.7% did not benefit from the presentation of the model. Analysis showed that persistent failure in the copy condition was the best level of differentiation between normal and AD subjects., (Copyright 2006 S. Karger AG, Basel.)