[Legal capacity and instruments assessing cognitive functions in patients with dementia]

The term "legal capacity" refers to the ability of a person to make a valid declaration of his will or to accept such a declaration. This ability constitutes the main condition for the validity of the legal transaction. The legal transaction includes issues that are adjusted by the Civil Code with which the relations of the citizens in a society are regulated. General practitioners and legal advisors, in any case of a person with cognitive impairment of various severity, should take into account that the assessment tests of the cognitive functions are not by themselves diagnostic of the dementia and they cannot be used as the only way of evaluation of the capacity of patients with cognitive impairment or possible dementia to respond to the needs of everyday life and in more complex decisions, such as the legal capacity. The existing methods for the assessment of the cognitive functions are valuable, mainly, for the detection of any cognitive impairment which may not be perceptible during the clinical evaluation of the patient and secondly for the detection of any changes in the cognitive status of the patient during its following up. The description and study of the instruments which are frequently used in the international scientific society for the assessment of the cognitive functions of the patients with mild cognitive impairment or dementia, during the evaluation of the legal capacity of these patients. The literature relevant to the existing methods assessing the cognitive functions during the evaluation of the legal capacity of patients with dementia was reviewed. The scientific database searched was Pubmed, Medline and Scopus. The key-words used were cognitive functions, dementia, instruments, legal capacity. Various instruments which assess the cognitive functions have been developed and can be grouped in 4 categories. The first one includes instruments used for the general assessment of the cognitive status. These instruments can be extensive or short and consist of subtests for the evaluation of several cognitive functions (memory, attention, perception, speech). The second category includes instruments for the specific assessment of the cognitive status, namely specific tests for one cognitive domain (for example, memory, speech flow, naming). The third category consists of methods which are based on the clinical evaluation during the interview with the patient and his familiars, giving emphasis on the frontal functions of the patient. Finally, the fourth group includes instruments which assess the executive functions of the patients. There is a great need for the development of more studies for the methods/instruments with which the cognitive functions of patients with probable dementia can be assessed during the evaluation of the legal capacity of these patients. The challenge for the scientists is to develop a clinically applicable instrument for the quick and reliable assessment of the legal capacity of people with dementia. The assessment of this ability should be done in relation with the needs, the feelings and the values of the patient.