Abstract and Introduction
Abstract
Purpose of Review. To critically discuss the neuropsychiatric symptoms in the prodromal stages of dementia in order to improve the early clinical diagnosis of cognitive and functional deterioration.
Recent Findings. Current criteria for cognitive syndrome, including Alzheimer's disease, comprise the neuropsychiatric symptoms in addition to cognitive and functional decline. Although there is growing evidence that neuropsychiatric symptoms may precede the prodromal stages of dementia, these manifestations have received less attention than traditional clinical hallmarks such as cognitive and functional deterioration. Depression, anxiety, apathy, irritability, agitation, sleep disorders, among other symptoms, have been hypothesized to represent a prodromal stage of dementia or, at least, they increase the risk for conversion from minor neurocognitive disorder to major neurocognitive disorder. Longitudinal investigations have provided increased evidence of progression to dementia in individuals with minor neurocognitive disorder when neuropsychiatric symptoms also were present.
Summary. Although neuropsychiatric symptoms are strongly associated with a higher risk of cognitive and functional deterioration, frequently the clinician does not acknowledge these conditions as increasing the risk of dementia. When the clinician accurately diagnoses neuropsychiatric symptoms in the prodromal stage of dementia, he could early establish appropriate treatment and, may be, delay the beginning of clinical and functional deterioration.
Introduction
Whereas progressive cognitive decline and functional disturbances have been established as typical clinical hallmarks of dementia, neuropsychiatric symptoms are currently considered an intrinsic condition associated with neurodegenerative processes. However, these symptoms have been less emphasized in the preclinical stages of dementia.
An extensive review of population-based multicentric studies reported an overall last month prevalence of 31% of psychopathological features in cognitive impairment nondemented individuals (CINDs) and about 15.1% in cognitive normal individuals.
The presence of psychopathological manifestations among nondemented elderly people was designated as mild behavioral impairment (MBI). Agitation, anxiety, apathy, depression, delusions, sleep disorders, loss of social skills, perseverant behaviors, loss of insight, dietary changes, impulsivity, irritability, among others, have been considered as evidences of persistent behavioral changes in MBI.
In addition to the neurobiological predictors of dementia, neuropsychiatric conditions may also represent the determinants of the disease progression. Thus, it becomes crucial to understand the prodromal behavioral stage of Alzheimer's disease and other dementias. As precocious intervention seems to be more efficacious, this knowledge might contribute to the diagnosis, thus allowing a better response to pharmacological and nonpharmacological treatments.
This review aims to discuss the neuropsychiatric symptoms in the prodromal stages of Alzheimer's disease and other dementias, the diagnosis accuracy of these symptoms and the outcome of these clinical manifestations in cognitive and functional deterioration.