Heterogeneity of the mild cognitive impairment syndrome (specialized outpatient service data analysis)

Timely diagnosis and optimal management of patients with cognitive impairment (CI) without dementia can potentially reduce the risk of their progression to dementia. In our study, we assessed the features of mild CI (MCI) syndrome in patients with neurological disorders based on the specialized outpatient service data analysis.

Objective: to analyze clinical, neuropsychological, and neuroimaging characteristics of MCI syndrome in the Russian population in real clinical practice.

Patients and methods. We enrolled 515 patients (209 men and 306 women, mean age – 71.2±8.0 years) with memory and/or other cognitive complaints. Seventy healthy volunteers (25 men and 45 women, mean age – 69.5±5.71 years) without cognitive complaints and central nervous system or mental disorders were enrolled in the control group. DSM-V diagnostic criteria for mild neurocognitive disorder were used. Participants underwent comprehensive neuropsychological testing with a qualitative and quantitative assessment of the results. In some of them (29.13%), brain magnetic resonance imaging (MRI) was performed.

Results and discussion. The following types of MCI were identified in study participants: monofunctional non-amnestic type (MFNAT) – 1.2%, monofunctional amnestic type (MFAT) – 12.6%, polyfunctional amnestic type (PFAT) – 22.9%, polyfunctional non-amnestic type (PFNAT) – 63.3%. We found a higher prevalence of executive dysfunction and attention deficit in PFNAT, and executive dysfunction, attention deficit, and memory decline in PFAT. Cardiovascular risk factors and signs of vascular leukoencephalopathy on MRI were more frequently observed in PFNAT and PFAT.

Conclusion. The clinical and neuropsychological analysis allows us to assume the pathophysiology of CI before the development of dementia. In the Russian population, cerebrovascular insufficiency plays a significant role in the development of MCI syndrome.

1. Yakhno NN. Cognitive disorders in a neurological clinic. Nevrologicheskiy zhurnal. 2006;11(S1):4-12 (In Russ.).

2. Yakhno NN, Zakharov VV, Lokshina AB, et al. Dementsii. Rukovodstvo dlya vrachey [Dementia. Guidance for doctors]. 3rd ed. Moscow: MEDpress-inform; 2011. P. 17-28. Available from: https://www.03book.ru/upload/iblock/987/415_Demencija_Jahno.pdf (accessed May 30, 2020) (In Russ.).

3. Yakhno NN, Zakharov VV, Lokshina AB. Moderate cognitive impairment syndrome in cerebral vascular insufficiency. Zhurnal nevrologii i psihiatrii imeni S.S. Korsakova. 2005;105(2):13-7 (In Russ.).

4. Yakhno NN, Zakharov VV, Koberskaya NN, et al. Premild (subjective and subtle) cognitive disorders. Nevrologicheskiy zhurnal. 2017;22(4):198-204. doi: 10.18821/1560-9545-2017-22-4-198-204 (In Russ.).

5. Zakharov VV, Savushkina IY, Mkhitaryan EA, et al. Age-related dynamics of cognitive functions in persons aged 50–85 years. Adv Gerontol. 2018; 8(1):41-6. doi: 10.1134/S2079057018010137

6. Yakhno NN, Zakharov VV, Lokshina AB. Impairment of memory and attention in the elderly. Neurosci Behav Physiol. 2007;37(3):203-8. doi: 10.1007/s11055-007-0002-y

7. Yakhno NN, Koberskaya NN, Zakharov VV, et al. The influence of age, comorbide cardiovascular and emotional factors on subtle cognitive decline in average, elderly and old age. Nevrologicheskiy zhurnal. 2018;23(6):309-15. doi: 10.18821/1560-9545-2018-23-6-309-315 (In Russ.).

8. Yakhno NN, Koberskaya NN, Zakharov VV, et al. The influence of age, gender, comorbide cardiovascular and emotional factors on subjective cognitive decline. Nevrologicheskiy zhurnal. 2018;23(4):184-9. doi: 10.18821/1560-9545-2018-23-4-184-189 (In Russ.).

9. Dementia. Comprehensive Principles and Practice. Oxford University Press; 2014. P. 377-383, 432-448. doi: 10.1093/med/9780199928453.001.0001

10. Parfenov VA, Zaharov VV, Preobrazenskaya IS. Kognitivnyye rasstroystva [Cognitive impairment]. Moscow; 2014. 192 p. (In Russ.).

11. Petersen RC, Lopez O, Armstrong MJ, et al. Practice guideline update summary: Mild cognitive impairment: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology. Neurology. 2018;90(3):126-35. doi: 10.1212/WNL.0000000000004826

12. Roberts RO, Geda YE, Knopman DS, et al. The Mayo Clinic Study of Aging: design and sampling, participation, baseline measures and sample characteristics. Neuroepidemiology. 2008;30(1):58-69. doi: 10.1159/000115751

13. Plassman BL, Langa KM, Fisher GG, et al. Prevalence of cognitive impairment without dementia in the United States [published correction appears in Ann Intern Med. 2009 Aug 18;151(4):291-2]. Ann Intern Med. 2008;148(6):427-34. doi: 10.7326/0003-4819-148-6-200803180-00005

14. Farias ST, Mungas D, Reed BR, et al. Progression of mild cognitive impairment to dementia in clinic – vs community-based cohorts. Arch Neurol. 2009;66(9):1151-7. doi: 10.1001/archneurol.2009.106

15. Petersen RC, Smith GE, Waring SC, et al. Aging, memory, and mild cognitive impairment. Int Psychogeriatr. 1997;9 Suppl 1:65-9. doi: 10.1017/s1041610297004717

16. Petersen RC, Smith GE, Waring SC, et al. Mild cognitive impairment: clinical characterization and outcome. Arch Neurol. 1999;56(3):303-8. doi: 10.1001/archneur.56.3.303

17. Petersen RC, Stevens JC, Ganguli M, et al. Practice parameter: early detection of dementia: mild cognitive impairment (an evidence-based review). Report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2001;56(9):1133-42. doi: 10.1212/wnl.56.9.1133

18. Petersen RC. Mild cognitive impairment: where are we? Alzheimer Dis Assoc Disord. 2005;19(3):166-9. doi: 10.1097/01.wad.0000179417.95584.90

19. Touchon J. Recent consensus efforts in the diagnosis of mild cognitive impairment. Psychogeriatrics. 2006;6(s1):S23-S25. doi: 10.1111/j.1479-8301.2006.00130.x

20. Zakharov VV. Dopaminergic and noradrenergic therapy of cognitive impairment. Zhurnal nevrologii i psihiatrii imeni S.S. Korsakova. 2006;106(9):43-7 (In Russ.).

21. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Diseases. Fifth Edition. (DSM-V). London; 2013. Available from: https://www.psychiatry.org/psychiatrists/practice/dsm

22. Lokshina AB. Modern aspects of diagnosis and treatment of mild cognitive impairment. Rossijskij zhurnal geriatricheskoj mediciny = Russian Journal of Geriatric Medicine. 2020;(3):199-204. doi: 10.37586/2686-8636-3-2020-199-204 (In Russ.).

23. Gorelick PB, Scuteri A, Black SE, et al. Vascular contributions to cognitive impairment and dementia: a statement for healthcare professionals from the american heart association/american stroke association. Stroke. 2011;42(9):2672-713. doi: 10.1161/STR.0b013e3182299496

24. Sachdev P, Kalaria R, O'Brien J, et al; Internationlal Society for Vascular Behavioral and Cognitive Disorders. Diagnostic criteria for vascular cognitive disorders: a VASCOG statement. Alzheimer Dis Assoc Disord. 2014;28(3):206-18. doi: 10.1097/WAD.0000000000000034

25. Smith EE, Barber Ph, Field TS, et al. Canadian Consensus Conference on Diagnosis and Treatmentof Dementia (CCCDTD)5: Guidelines for management of vascular cognitive impairment. Alzheimers Dement. 2020;6(1):e12056. doi: 10.1002/trc2.12056. eCollection 2020.

26. Goloveva AG, Zakharov VV. The etiology, manifestations, and therapy of chronic cerebrovascular diseases. Nevrologiya, neiropsikhiatriya, psikhosomatika = Neurology, Neuropsychiatry, Psychosomatics. 2020;12(5):84- 91. doi: 10.14412/2074-2711-2020-5-84-91 (In Russ.).

27. Albert MS, DeKosky ST, Dickson D, et al. The diagnosis of mild cognitive impairment due to Alzheimer's disease: Recommendations from the National Institute on Aging – Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease. Alzheimers Dement. 2011 May;7(3):270-9. doi: 10.1016/j.jalz.2011.03.008. Epub 2011 Apr 21.

28. Zakharov VV, Voznesenskaya TG. Nervnopsikhicheskiye narusheniya: diagnosticheskiye testy [Neuropsychiatric disorders: diagnostic tests]. 6th ed. Moscow: Medpress-inform; 2018. 320 p. Available from: https://staticru.insales.ru/files/1/4942/10457934/original/nervno_psix_nar.pdf (accessed 24.02.2021 (In Russ.).

29. Litvinenko IV, Emelin AYu, Lobzin VYu, Kolmakova KA. Neuroimaging techniques for diagnosing Alzheimer’s disease and cerebrovascular diseases with cognitive impairment. Nevrologiya, neiropsikhiatriya, psikhosomatika = Neurology, Neuropsychiatry, Psychosomatics. 2019;11(Suppl. 3):18-25. doi: 10.14412/2074-2711-2019-3S-18-25 (In Russ.).

30. Dongping R, Xiong L, Muni T, et al. Prevalence of mild cognitive impairment and its subtypes in community-dwelling residents aged 65 years or older in Guangzhou, China. Arch Gerontol Geriatr. 2018;(75):70-5. doi: 10.1016/j.archger.2017.11.003