Motor/Psychomotor Dysfunction in Normal Aging, Mild Cognitive Decline, and Early Alzheimer's Disease: Diagnostic and Differential Diagnostic Features

Abstract

To determine the association between cognitive dysfunction and motor behavior in older adults, 41 cognitively normal elderly (NL), 25 nondemented patients exhibiting mild cognitive impairment (MI) and at risk for future decline to dementia, and 25 patients with mild (early) Alzheimer's disease (AD) were examined using a wide array of motor/psychomotor and cognitive assessments. The three groups were recruited from an aging and dementia research center and were composed of well-characterized physically healthy volunteers, with similar ages and gender distributions. The outcome measures included 16 motor/psychomotor tests categorized a priori into gross, fine, and complex, as well as eight cognitive tests of memory and language. Relative to the NL group, MI individuals performed poorly on cognitive, fine, and complex motor measures but not on gross motor tests; AD patients performed worse on cognitive and all motor domains. Differences in complex motor function persisted after adjustment for performance on cognitive and on less complex motor tests. Classification analyses showed similar accuracies in discriminating NL from MIand NL from ADcases for both complex motor (79% and 92% accuracy, respectively) and cognitive tests (80% and 93% accuracy, respectively). Less complex motor tests produced poorer accuracies. Among nondemented subjects, education correlated with several cognitive scores but no motor scores. These results indicate that motor impairment is an important aspect of cognitive decline in older adults. Motor/psychomotor assessments were found to be comparably sensitive to traditional tests of cognitive function in identifying persons affected by the earliest stages of AD pathology and may improve identification of at-risk nondemented elderly, especially among diversely educated individuals.

Classification criteria for mild cognitive impairment

“…Previous clinical studies of MCI have suggested that subjects with MCI may have smaller medial temporal lobe volumes, [8][9][10][11] and that risk factors for progression from MCI to AD are higher age, the presence of the APOE ⑀4 allele, fine motor deficit, and lower premorbid IQ. 7,12 These factors are considered in the current general population validation study. The cognitive tests used to investigate MCI thus far have often been limited to those used to identify AD, or tests of general ability.…”

“…This point has already been the subject of much debate, as an increasing number of studies conclude that subjects with MCI, although having primarily memory complaints, also commonly show deficits on tasks of language, 12,20 orientation, 10 and praxis. 12,20 Although there is some evidence that a purely mnesic syndrome may exist within a clinical context, 7 this appears to be a rare occurrence when the full range of cognitive functions are examined. 21 Adhering to the strict criteria of isolated memory complaint in this study would have led to unacceptable levels of sensitivity, with the number of cases of isolated deficit falling well below the expected prevalence of AD itself.…”

Human adipose tissue‐derived mesenchymal stem cells improve cognitive function and physical activity in ageing mice

“…Key words: ageing; cognitive function; physical activity; human adipose-derived mesenchymal stem cell; brain-derived neurotrophic factor; nerve growth factor Ageing is associated with progressive functional and structural deterioration of neural systems, affecting both cognitive and motor functions (Kluger et al, 1997;Volkow et al, 1998). Cholinergic nerve cells in the basal forebrain undergo neurodegenerative changes during normal ageing as well as in Alzheimer's disease (AD; Bartus et al, 1982;Grothe et al, 2012).…”

Slowing of Alternating Forearm Movements Is Associated with Cognitive Impairment in Community-Dwelling Older People

“…Diagnostic sensitivity has been reported to increase when measures of specific motor impairment are included in cognitive assessment batteries [14] . Assessment of motor characteristics, in contrast to verbally based measures of cognitive function, is not likely to be influenced by education or linguistic background [10,14,15] .…”