Frontal lobes pathology and dementia. An appraisal of the contribution of Leonardo Bianchi.

This paper which was inspired by Leonardo Bianchi's work, published in English a hundred years ago, summarizes the main features of frontal dementias, with particular emphasis on Pick's Disease (PiD) and on Frontal Lobe Dementia (FLD). We intend to examine on one hand whether these behavioral changes follow pathology strictly limited to the frontal lobes and on the other hand whether these changes truly constitute a dementia. Currently available data suggest the following conclusions: 1) Lesions to the frontal lobes produce a dementia which is clearly different from the typical picture of Alzheimer's disease and which can be called a behavioral dementia. 2) The pathology of the so-called frontal dementias usually extends beyond the limits of the prefrontal cortex. 3) Executive functions classically thought to be related to frontal lobe structures are in fact associated with structures outside the frontal lobes, particularly in the telencephalic and limbic cortex. These findings in no way diminish the value of the work of Leonardo Bianchi. Rather, they strengthen it. We consider that the work of this great Neuroscientist remains highly relevant and that after 100 years, it still represents the starting basis for further works and ideas.