[Q-ACP: a questionnaire for evaluating visual and gestural complaints in patients with posterior cortical atrophy]

Posterior cortical atrophy (PCA) is a clinical neurodegenerative syndrome associated with atrophy in parieto-occipital cortices, and characterized by prominent disorders of higher visual processing, affecting both dorsal and ventral streams.

We used a questionnaire (Q-ACP) specifically designed to assess visual and praxis dysfunctions in PCA. The Q-ACP contains 32 items (combined in 12 domains) aimed at describing everyday deficiencies that patients or caregivers notice about visual and gestural domains. It was administered to 34 patients with PCA (MMSE = 20.0 ± 5.1) which were compared with 17 patients with Alzheimer's disease (AD) (MMSE = 23.4 ± 1.9) and 31 normal controls (MMSE = 28.9 ± 1.1).

Q-ACP of PCA patients (18.4 ± 5.3) was significantly greater than those of AD patients (2.7 ± 2.0) or normal controls (0.97 ± 1.6), and revealed disproportionate deficits on questions of visuospatial ability. Q-ACP was comparable in right (18.5 ± 4.3) and left (18.2 ± 6.8) PCA patients (p = 0.88). There was a negative correlation between MMSE and Q-ACP in PCA patients (r = -0.36; p = 0.045), but not in AD patients (r = -0.21; p = 0.42). When only the 22 PCA patients with MMSE equal or greater than 20 were considered, their Q-ACP score (17.2 ± 5.3) remained significantly greater than those of AD patients and normal controls (p = 0.0001). Controls had difficulties for only 12 of the 32 questions, and AD patients for 20 questions, whereas each of the 32 questions could be abnormal in the PCA group. The less often reported difficulties by PCA patients were for more easily reading small than big letters (14.7 %) whereas the most frequently impaired questions were for spatial and apractic agraphia (88.2 % for each question). Of the 12 domains of Q-ACP, all were impaired in PCA patients, 11 in AD patients and seven in controls.

Q-ACP is a useful tool for assessing visual and praxis everyday difficulties of patients with PCA. These difficulties are rarely observed in normal aged controls or patients with mild AD.