Mild cognitive impairment

Mild cognitive impairment (MCI) is a neurocognitive disorder which involves cognitive impairments beyond those expected based on an individual's age and education but which are not significant enough to interfere with instrumental activities of daily living. MCI may occur as a transitional stage between normal aging and dementia, especially Alzheimer's disease. It includes both memory and non-memory impairments. The cause of the disorder remains unclear, as well as both its prevention and treatment, with some 50 percent of people diagnosed with it going on to develop Alzheimer's disease within five years. The diagnosis can also serve as an early indicator for other types of dementia, although MCI may remain stable or even remit. Mild cognitive impairment has been relisted as mild neurocognitive disorder in DSM-5, and in ICD-11, the latter effective on 1 January 2022. MCI can present with a variety of symptoms, but is divided generally into two types. Amnestic MCI (aMCI) is mild cognitive impairment with memory loss as the predominant symptom; aMCI is frequently seen as a prodromal stage of Alzheimer's disease. Studies suggest that these individuals tend to progress to probable Alzheimer's disease at a rate of approximately 10% to 15% per year. It is possible that being diagnosed with cognitive decline may serve as an indicator of MCI. Nonamnestic MCI (naMCI) is mild cognitive impairment in which impairments in domains other than memory (for example, language, visuospatial, executive) are more prominent. It may be further divided as nonamnestic single- or multiple-domain MCI, and these individuals are believed to be more likely to convert to other dementias (for example, dementia with Lewy bodies). The International Classification of Diseases classifies MCI as a "mental and behavioural disorder." Mild cognitive impairment (MCI) may be caused due to alteration in the brain triggered during early stages of Alzheimer's disease or other forms of dementia. Exact causes of MCI are unknown.