Mild behavioral impairment: A prodromal stage of dementia

Abstract

Mild cognitive impairment (MCI) was defined by Petersen et al. (1999) as progressive memory loss, a prodrome of Alzheimer’s disease. MCI is a well-established entity that can be both a diagnosis in medical practice and a valid target of Alzheimer’s prevention therapy. More recently MCI has expanded to include other cognitive domains with other potential causes: amnestic MCI, multiple domains MCI, and single domain non-amnestic MCI. Behavioral symptoms in MCI are associated with a higher risk of dementia, but their association with dementia risk in patients without MCI is unknown. The objective of our paper was to address the question of whether aging patients with behavioral symptoms with or without cognitive impairment represent a population at risk for dementia. Mild Behavioral Impairment (MBI) defines a late life syndrome with prominent psychiatric and related behavioral symptoms in the absence of major cognitive symptoms. MBI also appears to be a transitional state between normal aging and dementia. MBI may carry a higher risk for dementia than MCI. A subgroup of MBI patients is likely to exhibit symptoms of a frontotemporal dementia (FTD) prodrome. We proposed 4 subtypes of patients at risk for dementia: amnestic MCI (which is said to progress preferentially to Alzheimer’s disease), multiple domain MCI (which may represent normal aging or may progress to vascular cognitive impairment or a neurodegenerative disorder), single domain non-amnestic MCI, and MBI (which may progress to frontotemporal dementia, Lewy Body dementia or Alzheimer’s disease). We concluded that MBI is a counterpart of MCI as a transitional state between normal aging and dementia. These findings have implications for early detection, prevention, and treatment of patients with late-life dementia.

Prevalence of Cognitive Impairment and Depression among a Population Aged over 60 Years in the Metropolitan Area of Guadalajara, Mexico

“…Although rates of progression are widely different across studies and populations, it has been found that the rate at which patients with cognitive impairment progress to dementia is about 70% over a period of 5 years, that is, 10%–15% per year as opposed to 1%-2% of control subjects [31]. Thus, its early detection is of great importance to develop preventive and early rehabilitation.…”

Mild Behavioral Impairment and Risk of Dementia

“…Of the latter patients, 36% had FTD, 28% had AD; 18% had VaD and 18% had other types of dementia16. As a result we proposed the syndrome of “Mild Behavioral Impairment” (MBI) consisting of: (1) persistent behavioral changes and mild psychiatric symptoms, especially disinhibition; (2) no serious cognitive complaints; (3) normal activities of daily living; and (4) absence of dementia16-18. MBI has been hypothesized to confer increased risk for dementia development, especially of FTD, whether or not significant cognitive symptoms are present.…”

“…For example we reported that in 50% of a series of dementia patients who consulted our service NPS were the first indication of change, before the occurrence of cognitive symptoms. Of the latter patients, 36% had FTD, 28% had AD; 18% had VaD and 18% had other types of dementia16. As a result we proposed the syndrome of “Mild Behavioral Impairment” (MBI) consisting of: (1) persistent behavioral changes and mild psychiatric symptoms, especially disinhibition; (2) no serious cognitive complaints; (3) normal activities of daily living; and (4) absence of dementia16-18.…”

Mild Behavioral Impairment: A Prodromal Stage of Frontotemporal Lobar Degeneration

“…The last presents as impairment in a single cognitive domain other than memory, such as a dysexecutive syndrome. This condition was described as mild behavioral impairment (MBI) and as MCI of the frontotemporal type 3,4 …”