Construction-LBD (Constructional Apraxia in Alzheimer's Disease (AD) and Lewy Body's Dementia (LBD))

Overview

Alzheimer's disease (AD) and Lewy body's dementia (LBD) are two frequent neurodegenerative pathologies. They differ in their expression, their evolution but share same features which make their diagnosis uneasy. Constructional apraxia has been described in both disease.The underlying mechanisms have been less studied and could be different in AD and LBD. The definition of the constructional apraxia is purely descriptive and few models are inconclusive. It is admitted that drawing tasks involve visuo-perceptive and visuo-spatial abilities, executive functions and working memory as well as purely "constructive" skills. Regarding to different studies, visuo-perceptive abilities are more severely impaired in LBD than in AD and are considered as an early onset sign of the disease. Executive functions deficits are documented in AD and LDB and could contribute to the drawing impairment. It is possible to compensate the planning disorders in giving patient the best strategy to use. If drawing impairment persists, they should result of others mechanisms like visuo-perception, visuo-spatial or constructive deficits. The investigators suggest that giving the best planning strategy will help more AD patients who are supposed to fail in raison of an executive impairment, than the LDB group who is supposed to present visuo-perceptive deficits. An MRI will be proposed to study the cerebral areas involved in constructional apraxia.

Conditions