title: Constructional apraxia as a distinctive cognitive and structural brain feature of pre-senile Alzheimer's disease.
abstract: Constructional apraxia (CA) is often, but not always, observed in patients with Alzheimer's disease (AD). CA is usually explained by impairment of either basic perceptual and motor abilities, or executive functions. This study aims to evaluate the structural correlates of CA in AD. Forty-eight patients with AD and 20 healthy age-matched controls underwent a thorough neuropsychological investigation and an MRI scan to collect high-resolution T1-weighted data. Patients were classified as having (ADca) or not having (ADnonca) CA based on performance on the Freehand copying of drawings task. T1-weighted volumes were process according to the voxel based morphometry protocol, to assess the presence of significant differences in local to grey matter volumes in patients compared to controls and in ADca compared to ADnonca. Post-hoc, the mean grey matter volume of clusters that resulted significantly different between groups was regressed against the neuropsychological scores in which the two patient groups performed differently. A pre-senile disease onset was significantly more frequent in patients with CA compared to ADnonca. ADca patients also showed worse performances than patients with ADnonca at some tests requiring the processing of visuo-spatial data and testing working memory. They also showed widespread reductions in grey matter volume, mainly located in areas known to be implicated in object recognition and localization, and in maintenance and re-orienting of spatial attention. These findings suggest that the occurrence of CA in AD is often associated with a peculiar clinical onset (i.e., pre-senile), neuropsychological profile, and distribution of grey matter atrophy.
authors: Neuroimaging Laboratory, Santa Lucia Foundation, IRCCS, Rome, Italy.
authors: Laura
authors: L
authors: Serra
authors: Lucia
authors: L
authors: Fadda
authors: Roberta
authors: R
authors: Perri
authors: Barbara
authors: B
authors: Spanò
authors: Camillo
authors: C
authors: Marra
authors: Diana
authors: D
authors: Castelli
authors: Mario
authors: M
authors: Torso
authors: Elena
authors: E
authors: Makovac
authors: Mara
authors: M
authors: Cercignani
authors: Carlo
authors: C
authors: Caltagirone
authors: Marco
authors: M
authors: Bozzali
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications* / Q000473:pathology; D001072:Apraxias / Q000175:diagnosis* / Q000209:etiology*; D001921:Brain / Q000473:pathology*; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D014706:Verbal Learning
keywords: Alzheimer's disease; constructional praxis; drawing tasks; voxel-based morphometry