Transition from Cognitively Impaired Not Demented to Alzheimer’s Disease: An Analysis of Changes in Functional Abilities in a Dementia Clinic Cohort

Abstract

Background: Patients with cognitive impairment no dementia (CIND) are at an increased risk of progression to Alzheimer’s disease (AD). Whether subtle impairments in functional or social abilities at the CIND stage can predict progression to AD is not yet fully determined. We evaluated whether impairments on the Disability Assessment for Dementia (DAD) and Functional Rating Scale (FRS) can predict progression to AD. Methods: We examined 70 patients with CIND from the ACCORD cohort having complete DAD and FRS baseline and 2-year follow-up data. MANCOVA adjusted for age, sex, education and baseline MMSE score compared the baseline and 2-year change in DAD and FRS scores in CIND patients who progressed to AD versus non-progressors. Results: There were no significant differences between CIND progressors and non-progressors in baseline total DAD or FRS scores. FRS domain analysis revealed that greater impairment in social/occupational functioning significantly predicted progression, while there were no predictive DAD domains. In progressors, both DAD and FRS scores significantly declined over time with the largest changes in instrumental activities of daily living (IADL). Conclusion: While changes in IADL characterize the progression from CIND to AD, impairment in complex social-cognitive competency significantly predicts risk of progression and may mark early AD.

Patterns of Loss of Basic Activities of Daily Living in Alzheimer Patients: A Cross-Sectional Study of the French REAL Cohort

“…Previous studies found a later decline for BADL than for IADL in AD or in mild cognitive impairment, and this was also true for the REAL cohort [22,31] . Other studies showed a rapid decline in BADL for AD patients with severe cognitive decline [32] .…”

“…The fact that in the REAL cohort the MMSE range was wide (10-26 at inclusion) permitted us to perform the present study, because several studies underline a marked link between cognitive impairment and functional decline in AD patients [20][21][22] . The finding of a pattern of loss of ADL depends on the score for each activity, according to the scale used.…”

Development of a patient‐reported outcome instrument to assess complex activities of daily living and interpersonal functioning in persons with mild cognitive impairment: The qualitative research phase

“…Existing measures used to quantify treatment effects in mild-tomoderate AD may not be sufficiently sensitive to capture the more subtle cognitive and functional impairments that persons with MCI experience. Some functional impairment may begin during the predementia (MCI) phase of AD [4,5].…”

“…Impairments in higher order cADLs, such as financial capacity, social planning, complex verbal facility, and other skills and activities related to executive function, may be among the earliest deficits in persons with MCI [4,6,7]. Furthermore, people with MCI may note deficits in some activities, such as reading, long before the deficit is observable to others [6,7].…”

Cognitive and Noncognitive Determinants of Everyday Activities in a Racially Diverse Population of Older Persons Receiving Health Services

“…For example, the diagnostic criteria for mild cognitive impairment (MCI) include ''essentially intact'' functioning, whereas criteria for dementia require impaired daily functioning (American Psychiatric Association, 1994;Petersen et al, 2009). Many studies have found, however, that persons with MCI have difficulty with cognitively demanding activities like managing finances and medications and that these difficulties predict progression to dementia or, in fact, represent early Alzheimer's disease (AD; Allaire et al, 2009;Farias et al, 2006;Hsiung et al, 2008;Okonkwo et al, 2006;Peres et al, 2006). Despite the pivotal role of functional status for case definition, no valid criteria exist to make diagnostic distinctions.…”