Dementia and consciousness: how the brain loses its self

Consciousness is based on the ability to rapidly integrate information and requires the optimal functioning of neural networks widely distributed between the thalami and the whole cortical mantle. Neurodegenerative processes that occur in dementing disorders, including Alzheimer’s disease, frontotemporal dementia and Lewy Body Disease, lead to a progressive disruption of the brain functional and anatomical connectivity that sustains complex mental activity in the human brain. Not only different dementia syndromes affect the brain in different ways but also patients with the same disease may show distinctive clinical features. By combining clinical, neuropsychological and functional brain imaging studies in selected patients, scientists are gaining new insights on the cerebral bases of conscious mental activity and of the neural events that make awareness of the surrounding world and of ourselves to dissolve.