The extent to which MCI may be a disabling process is largely unknown because the usual definition proposed by Petersen and colleagues,6,7 and adopted by most researchers in this area, stipulated that MCI is a state that does not interfere with everyday activities. More recently, this definition has been relaxed to include the possibility that MCI may impede, but not prevent, everyday functioning. On this basis, it has subsequently been shown that MCI may be associated with increasing difficulties in the performance of a wide range of everyday tasks, notably dressing, dental care, and the use of a telephone.8 We do not know,
on the other hand, to what extent MCI may indirectly Inhibitors,research,lifescience,medical lead to activity restriction Inhibitors,research,lifescience,medical due to, for example, withdrawal from a social activity due to fear of being embarrassed by a memory problem. Little
is currently known either about the extent to which MCI may influence mortality rates. While dementia has been clearly associated with increased mortality with a life expectancy on average of 8 years from the time of diagnosis, the impact of MCI on survival remains unclear. Cumulative mortality risk in MCI has been estimated by Gussekloo et al9 using a Cox proportional selleck hazards model with a cohort of 891 subjects from the Leiden Aging Study Compared Inhibitors,research,lifescience,medical with normal subjects the cumulative risk was found to be 2.5. The study is however, limited by Inhibitors,research,lifescience,medical its use of the Mini-Mental-State Examination (MMSE)10 to define MCI. How widespread is MCI in the general population? Establishing the prevalence and incidence of MCI has above all been hindered by the lack of an operational definition of the disorder adapted to general population use, where case selection cannot normally be based on a complete neurological examination. Early conceptualizations of subclinical cognitive deficit were based Inhibitors,research,lifescience,medical on the theoretical assumption that
such changes are distinct from dementia and other pathologies, being the consequence of inevitable aging-related cerebral changes, such as cortical atrophy, which may be considered a normal feature of the aging process. As parallel selleck chem Palbociclib research into the causes of dementia and cerebrovascular disease has now led to a clearer understanding of their etiology, it has also been shown that many of the physiological abnormalities seen in these disorders are also present to a lesser extent in normal subjects with cognitive complaints, but these factors cannot currently Dacomitinib be incorporated into diagnostic criteria due to difficulties in establishing precise universal cutoff points between MCI and normal subjects. The diagnostic criteria for MCI proposed by Petersen et al6 thus refer to complaints of defective memory and demonstration of abnormal memory functioning for age, which may be more easily quantified by reference to standard deviation from scores obtained by normal elderly subjects.