[Early signs of cognitive impairment: Definitions and diagnostic criteria]

To conduct a comparative analysis of existing approaches to determining the early stages of cognitive impairment, and based on the results, to propose a universal practical approach to their coding and develop diagnostic criteria.

A comparative analysis of available literature data was performed, including Russian and international sources in the PubMed and eLibrary databases addressing the issues of determining, diagnosing, preventing, and treating the predementia stages of cognitive deficits.

The article discusses various options for identifying the predementia stages of cognitive impairment. Based on the analysis, it is proposed to use the universal term-the early signs of cognitive impairment-in everyday practice to encode the stage of cognitive impairment preceding the moderate cognitive impairment (MCI). The following diagnostic criteria are proposed: the symptoms of decreased memory, attention, and general mental activity presented independently or identified during an interview; the symptoms are repeated at least once a week and are not associated with any obvious reasons and external factors; extended neuropsychological examination can reveal deviations from the reference indicators; the presence of risk factors for the development of cognitive impairment; the duration of symptoms is at least 6 months; concern about their condition due to a feeling of a worse cognitive activity in comparison with other people of the same age; no MCI criteria are met.

Early objective diagnosis of the initial stages of cognitive impairment is challenging even for trained, problem-oriented specialists; therefore, it is necessary to standardize and universalize the diagnostic criteria available at all stages of medical care. A comprehensive assessment of the symptoms, the circumstances of their occurrence, and their persistence and recurrence is necessary. Objective evidence of impairment should be standardized using a universal set of neuropsychological methods.