Mild Behavioral Impairment and Risk of Dementia

Abstract

Background Mild cognitive impairment (MCI) is a transitional state between normal ageing and dementia, at least for some patients. Behavioral symptoms in MCI are associated with a higher risk of dementia, but their association with dementia risk in patients without MCI is unknown. Mild Behavioral Impairment (MBI) refers to a late life syndrome with prominent psychiatric and related behavioral symptoms in the absence of prominent cognitive symptoms, which may also be a dementia prodrome. Objective To compare MCI and MBI patients and to estimate the risk of dementia development in these two groups. Method A consecutive series of 358 patients (239 with MCI; and 119 with MBI) presenting to an outpatient general hospital specialty clinic were followed for up to 5 years until conversion to dementia or censoring. Results 34% of MCI patients and over 70% of patients with MBI developed dementia (Logrank p=0.011). MBI patients without cognitive symptoms were more likely to develop dementia (Logrank p<0.001). MBI patients were more likely to develop dementia due to frontotemporal degeneration (FTD) as opposed to Alzheimer’s dementia (AD). Conclusion MBI appears to be a transitional state between normal ageing and dementia. MBI (specifically those without cognitive symptoms) may confer a higher risk for dementia than MCI and is likely an FTD prodrome in many cases. These findings have implications for the early detection, prevention, and treatment of patients with dementia in late life, by focusing on the emergence of new behavioral symptoms.

Association between Benzodiazepine Use and Dementia: Data Mining of Different Medical Databases

“…Some studies suggested that the frequency of symptoms is highly correlated with an increase in benzodiazepine prescriptions during the years preceding a diagnosis of dementia 12, 25, 26. Therefore, the observed association between benzodiazepine use and dementia may be due to confounding by indication and reverse causation.…”

The Mild Behavioral Impairment Checklist (MBI-C): A Rating Scale for Neuropsychiatric Symptoms in Pre-Dementia Populations

“…The 2011 National Institute on Aging-Alzheimer’s Association (NIA-AA) consensus recommendations for diagnosis of all cause dementia include “changes in personality, behavior, or comportment— symptoms include: uncharacteristic mood fluctuations such as agitation, impaired motivation, initiative, apathy, loss of drive, social withdrawal, decreased interest in previous activities, loss of empathy, compulsive or obsessive behaviors, socially unacceptable behaviors”[26]. While behavioral symptoms are well-recognized early manifestations of Frontotemporal Dementia (FTD) [27], they have been shown to appear early in Alzheimer’s and vascular dementias [28, 29]. It is not uncommon for patients with NPS who do not show obvious cognitive impairment to receive psychiatric diagnoses when the possibility of neurodegenerative disease has been overlooked [30].…”

Latent Classes of Neuropsychiatric Symptoms in NACC Controls and Conversion to Mild Cognitive Impairment or Dementia

“…Mild behavioral impairment (MBI) is defined as behavioral change lasting six months or longer, in the absence of cognitive and functional impairment (excluding a diagnosis of dementia or MCI or a psychiatric diagnosis) [27]. One prospective outpatient cohort study found that MBI, in the absence of cognitive impairment or a psychiatric diagnosis, was associated with significant risk of dementia (68% to frontotemporal dementia) [27].…”

“…One prospective outpatient cohort study found that MBI, in the absence of cognitive impairment or a psychiatric diagnosis, was associated with significant risk of dementia (68% to frontotemporal dementia) [27]. This study described the rates of specific NPS in the sample, but did not address the issue of which specific NPS or patterns of NPS are associated with cognitive decline and comprise the diagnosis of MBI.…”