Elucidating Mild Cognitive Impairment: a Review of Diagnostic Research

Mild cognitive impairment (MCI) is characterized by a level of cognitive impairment that is lower than normal for a person\u27s age, but higher functioning than a demented person. In the majority of cases people with mild cognitive impairment revert back to normal cognitive functioning. However MCI often evolves into other more serious etiologies such as but not limited to: Alzheimer’s, frontotemporal dementia, and dementia with Lewy bodies. Much effort has been made in determining the prognosis of a person with mild cognitive impairment. While treatment options are still in their exploratory stages (much of the work in this area has been fruitless) early intervention is considered to be imperative. Evidence does suggest that engaging in cognitively demanding activities (such as reading a book or playing a game of chess) can have a protective effect against the symptoms of dementia. Furthermore there are dietary changes that are correlated with better outcomes in many of the possible etiologies associated with mild cognitive impairment. This effort has led to the creation of sub-type classifications of mild cognitive impairment, some of which have been associated with an increased risk for a particular etiology. Here in, diagnostic techniques and methods are reviewed including: neuropsychological assessment, biomarkers in blood plasma, functional imaging (FDG PET & fMRI), Volumetric and morphological imaging (using MRI), dynamical analysis of EEG and MEG data, and spontaneous speech analysis. Also explored is the link between mild cognitive impairment and depression, as well as the evolution of the construct of MCI. Through investigation of these techniques and areas of interest it becomes clear that mild cognitive impairment is a complex clinical construct arising from a variety of causes and circumstances