[Subcortical dementia and the frontal lobe syndrome]

Subcortical dementia is a clinical syndrome incorporating disorders of cognitive and affective sphere, which is caused by organic damage to subcortical structures. The syndrome is usually connected with Progressive Supranuclear Palsy, Huntington Disease, Parkinson's Disease. Subcortical dementia is mainly characterized by: slowing down of psychic functions and impairment of their precision, disorders in the ability to use achieved knowledge and personality changes. Most authors stress the fact that similar cognitive and emotional personality defects are observed in cases of frontal cortex damage. Recent research points to the existence of functional subcortical-prefrontal circuits which regulate human behaviour. There is a link between subcortical dementia and functional or structural break of one or more cortical-subcortical connections. Attention is also called to disorders in certain neurotransmitting systems (dopaminergic, acetylcholinergic) as well as to brain hypometabolism in basal ganglia, thalamus and prefrontal cortex.