[Disorders of executive consciousness]

Executive function is a higher order cognitive capacity that involves memory, perception and performance of complex tasks. Disorders of the executive functions are sign of lesions in the prefrontal cortex, involving the prefrontal-striatal-thalamic networks and the parietal association areas. According to signs and localization, five basic prefrontal syndromes are recognised. 1. Damage in posterior dorsolateral prefrontal cortex and subcortical nuclei causes the dorsolateral syndrome with impaired decision making, working memory and planning. 2. The ventromedial-orbitofrontal syndrome: if lesion spares the basal forebrain, memory can be preserved, but poor social decision making develops. 3. The dorsomedial syndrome consists of attention disorder, akinesia, mutism and apathy. 4. The bilateral ventrolateral prefrontal regions serve perception of self and environment. 5. The ventral lateral (verbalizer) area of the dominant hemisphere coordinates language. Executive impairments can be found in cerebrovascular, Parkinson's and other diseases of basal ganglia, and in frontotemporal lobar degeneration. The dorsolateral syndrome can be examined by the use of Wisconsin card sorting test, self ordered pointing task and the delayed response task. Prefrontal-basal function can be assessed by Gambling-, Faux Pas-, and Emotion identification tasks.

1. A dysexecutive syndrome does not fulfil the criteria of dementia. 2. A "frontal syndrome" is an indefinite eponym. Focal lesions in prefrontal systems lead to localization-specific symptoms, which can be defined by psychometric tests. 3. In neurological diseases associated with multifocal damage of the brain neuropsychologic tests may help to determine strategic lesions, which are responsible for the actual syndromes.