Clinical and Dynamic Features and Prognostic Value of Non-Cognitive Psychopathological Symptoms in Mild Cognitive Impairment (MCI)

Abstract

Background: high prevalence of pre-dementia cognitive disorders (in particular mild cognitive impairment, MCI) in older people, unfavorable predictive value of MCI with a high risk of conversion to dementia, lack of a unified view of facultative, noncognitive psychopathological symptoms (NPS) in its syndromic structure, their clinical heterogeneity, close relationships with mild cognitive impairment syndrome is actualized by the analysis of the mutual influence of the components of MCI syndromes.The aim: to investigate clinical and dynamic features and determine the prognostic value of non-cognitive psychopathological symptoms in MCI, including various psychopathological symptoms (affective, psychotic, behavioral disorders).Patients and methods: a comparative dynamic prospective selective observational study of 264 older patients with MCI was carried out. The main study group included 189 patients with NPS; compared group made up 75 cases with MCI represented only by cognitive impairments. Repeated clinical, psychopathological and psychometric assessments (MMSE, MoCa, NPI) were performed at 12 and 24 months. Results: differences were revealed in the structure and dynamics of cognitive indicators in patients with dominance of affective, psychotic or behavioral symptoms. Patients with affective symptoms showed low scores on subtests of line drawing, phonemic fluency, and ability to verbal categorization (p < 0.05). In these individuals, with repeated measurements, the indices of delayed reproduction, retention, abstract thinking were significantly reduced in comparison with the results of the rest of the study participants (p < 0.05). Patients with psychotic symptoms showed the lowest indices of delayed reproduction, spatial-visual, speech tests, false reproductions both at the initial assessment and in the dynamics of observation (p < 0.05). But their parameters of counting, attention, working memory, “recognition” are higher in them than in representatives of other psychopathological subgroups (p < 0.05). It was found that mild cognitive impairment without psychopathological inclusions has a lower tendency to transform into dementia over a two-year follow-up period than MCI, in the structure of which non-cognitive psychopathological symptoms are present.Conclusions: non-cognitive psychopathological symptoms of MCI are heterogeneous in terms of clinical and dynamic characteristics. The structure and dynamics of cognitive indicators is different in the affective, psychotic, behavioral subgroups of patients with MCI. Individuals with affective pathology had the highest rate of MCI conversion to dementia. In patients with MCI without neuropsychiatric symptoms, a favorable course of cognitive impairment was more common than in patients with MCI with non-cognitive psychopathological symptoms.