ABSTRACT Background: Mild cognitive impairment (MCI) is a heterogeneous condition with a variety of clinical outcomes, the presence of which correlates with risk of Alzheimer’s disease as well as pre-clinical stages of other dementia subtypes. The aims of this study were to assess the specific patterns of cognitive profiles and to identify changes from baseline to 24 weeks in patients with MCI using detailed neuropsychological testing. Methods: We consecutively recruited 120 MCI patients at baseline according to the Petersen’s clinical diagnostic criteria, who were admitted to the Dementia and Memory Clinics. We analyzed patients who fulfilled both inclusion and exclusion criteria for MCI and classified them into four subtypes according to deficits in major cognitive domains; amnestic MCI single domain (aMCI-s), amnestic multiple domain MCI (aMCI-m), non-amnestic single domain MCI (naMCI-s) and non-amnestic multiple domain MCI (naMCI-m). Four groups of MCI were evaluated by a detailed neuropsychological battery test. Results: 83 patients with MCI at the 24-week follow-up were classified into four subtypes. The most frequent subtype was amnestic multi-domain MCI, with the frequency of MCI subtypes as follows: aMCI-s (n = 21, 25.3%), aMCI-m (n = 53, 63.9%), naMCI-s (n = 5, 6.0%) and naMCI-m (n = 4, 4.8%). In the major cognitive items of the SNSB-D, there were significant changes between the initial and follow-up tests in the domains of language, memory and the fron-tal/executive function (p < 0.05), except for attention, in all MCI patient subtypes. At 24-weeks follow-up, the conversion rate to Alzheimer’s disease was 2.4% (n = 2) from a subtype of amnestic multi-domain MCI. Conclusions: Our study revealed the most frequent subtype of MCI to be multiple domain amnestic MCI, with this subtype having a higher tendency of conversion to Alzheimer’s disease.
Cite this paper
K. Park, E. Kim, H. Joo, S. Jeon, S. Choi, J. Kwon, B. Kim and J. Kim, "Cognitive Profiles and Subtypes of Patients with Mild Cognitive Impairment: Data from a Clinical Follow-Up Study," International Journal of Clinical Medicine, Vol. 3 No. 5, 2012, pp. 352-360. doi: 10.4236/ijcm.2012.35068.
 R. C. Petersen, R. Doody, A. Kurz, R. C. Mohs, J. C. Morris, P. V. Rabins, et al., “Current Concepts in Mild Cognitive Impairment,” Archives of Neurology, Vol. 58, No. 12, 2001, pp. 1985-1992.
 H. Amieva, L. Letenneur, J. F. Dartigues, I. Rouch- Leroyer, C. Sourgen, F. D’Alchee-Biree, et al., “Annual Rate and Predictors of Conversion to Dementia in Subjects Presenting Mild Cognitive Impairment Criteria Defined According to a Population-Based Study,” Dementia and Geriatric Cognitive Disorders, Vol. 18, No. 1, 2004, pp. 87-93. doi:10.1159/000077815
 P. Alexopoulos, T. Grimmer, R. Perneczky, G. Domes and A. Kurz, “Progression to Dementia in Clinical Sub-types of Mild Cognitive Impairment,” Dementia and Geriatric Cognitive Disorders, Vol. 22, No. 1, 2006, pp. 27-34. doi:10.1159/000093101
 The Canadian Study of Health and Aging Working Group, “The Incidence of Dementia in Canada,” Neurology, Vol. 55, No. 1, 2000, pp. 66-73. doi:10.1212/WNL.55.1.66
 R. C. Petersen, G. E. Smith, S. C. Waring, R. J. Ivnik, E. G. Tangalos and E. Kokmen, “Mild Cognitive Impairment: Clinical Characterization and Outcome,” Archives of Neurology, Vol. 56, No. 3, 1999, pp. 303-308.
 B. Winblad, K. Palmer, M. Kivipelto, V. Jelic, L. Fratiglioni, L. O. Wahlund, et al., “Mild Cognitive Impairment—Beyond Controversies, Towards a Consensus: Report of the International Working Group on Mild Cognitive Impairment,” Journal of Internal Medicine, Vol. 256, No. 3, 2004, pp. 240-246.
 F. Maioli, M. Coveri, P. Pagni, C. Chiandetti, C. Marchetti, R. Ciarrocchi, et al., “Conversion of Mild Cognitive Impairment to Dementia in Elderly Subjects: A Preliminary Study in a Memory and Cognitive Disorder Unit,” Archives of Gerontology and Geria-trics, Vol. 44, No. 1, 2007, pp. 233-241.
 P. Fischer, S. Jungwirth, S. Zehetmayer, S. Weissgram, S. Hoenigschnabl, E. Gelpi, et al., “Conversion from Subtypes of Mild Cognitive Impairment to Alzheimer Dementia,” Neurology, Vol. 68, No. 4, 2007, pp. 288-291.
 Y. Kang, D. L. Na and S. Hahn, “A Validity Study on the Korean Mini-Mental State Examination(K-MMSE) in Dementia Patients,” Journal of the Korean Neurological Association, Vol. 15, 1997, pp. 300-308.
 J. C. Morris, “The Clinical Dementia Rating (CDR): Current Version and Scoring Rules,” Neurology, Vol. 43, No. 11, 1993, pp. 2412-2414.
 Y. Kang and D. L. Na, “Seoul Neuropsychological Screening Battery,” Human Brain Research & Consulting Co., Seoul, 2003.
 H. J. Ahn, J. Chin, A. Park, B. H. Lee, M. K. Suh, S. W. Seo, et al., “Seoul Neuropsychological Screening Battery-Dementia Version (SNSB-D): A Useful Tool for Assessing and Monitoring Cog-nitive Impairments in Dementia Patients,” Journal of Korean Medical Science, Vol. 25, No. 7, 2010, pp. 1071-1076.
 H. Kim and D. L. Na, “Normative Data on the Korean Version of the Boston Naming Test,” Journal of Clinical and Experimental Neuropsychology, Vol. 21, No. 1, 1999, pp. 127-133. doi:10.1076/jcen.18.104.22.1682
 J. T. Tschanz, K. A. Welsh-Bohmer, C. G. Lyketsos, C. Corcoran, R. C. Green, K. Hayden, et al., “Conversion to Dementia from Mild Cognitive Disorder: The Cache County Study,” Neurology, Vol. 67, No. 2, 2006, pp. 229- 234. doi:10.1212/01.wnl.0000224748.48011.84
 M. Zanetti, C. Ballabio, C. Abbate, C. Cutaia, C. Vergani and L. Bergamaschini, “Mild Cognitive Impairment Subtypes and Vascular Dementia in Community-Dwelling Elderly People: A 3-Year Follow-Up Study,” Journal of the American Geriatrics Society, Vol. 54, No. 4, 2006, pp. 580-586. doi:10.1111/j.1532-5415.2006.00658.x
 A. Busse, A. Hensel, U. Guhne, M. C. Angermeyer and S. G. Riedel-Heller, “Mild Cognitive Impairment: Long-Term Course of Four Clinical Subtypes,” Neurology, Vol. 67, No. 12, 2006, pp. 2176-2185.
 J. J. Manly, M. X. Tang, N. Schupf, Y. Stern, J. P. Vonsattel and R. Mayeux, “Frequency and Course of Mild Cognitive Impairment in a Multiethnic Community,” Annals of Neurology, Vol. 63, No. 4, 2008, pp. 494-506.
 S. Jungwirth, S. Weissgram, S. Zehetmayer, K. H. Tragl and P. Fischer, “VITA: Subtypes of Mild Cognitive Impairment in a Community-Based Cohort at the Age of 75 Years,” International Journal of Geriatric Psy-chiatry, Vol. 20, No. 5, 2005, pp. 452-458. doi:10.1002/gps.1311