[Posterior cortical atrophy. Its neuropsychological profile and differences from typical Alzheimer's disease]

The term 'posterior cortical atrophy' (PCA) refers to a neurodegenerative syndrome that is characterised by progressive alteration of the higher visual-perceptual and/or visual-spatial functions, which often presents Alzheimer's disease (AD).

To describe the value of neuropsychological tests in the differential diagnosis of patients with PCA versus patients with typical AD.

The sample was made up of four patients with PCA, four patients with initial typical AD with no significant differences in the degree of cognitive impairment according to the Minimental State Examination and seven cognitively healthy controls. Subjects were administered a full neuropsychological battery of tests for memory, language, praxias, executive functions, and visual-perceptual and visual-spatial capacities. The statistical analysis was performed using the Mann-Whitney U test for non-parametric tests and independent samples.

In the neuropsychological study, scores were significantly lower in the group with PCA compared to the control group in verbal comprehension, praxias and visual gnosias (p < 0.05), and significantly higher with respect to the group with typical AD in episodic memory tests (p < 0.05). In contrast, patients with PCA had a significantly lower score in comparison to typical AD in visual-perceptive and visual-spatial tests (p < 0.05), and in constructive praxias (p < 0.05).

Results in the neuropsychological tests show subjects with PCA and typical AD have different cognitive profiles, and are useful in the differential diagnosis of the two clinical variants.