The Biological Basis of Behavioral Symptoms in Dementia

Abstract

This article describes the pathophysiology of dementia and differentiates between cognitive and noncognitive symptoms that characterize this devastating illness. Relationships between brain anatomic and neurochemical systems and behavioral symptoms of dementia are discussed. An overview of the etiologies and neuropathologiesof dementia are presented as they relate to impairments in memory and intellectual abilities, personality changes, and behavioral symptoms. Recent genetic and molecular discoveries that have advanced our understanding of this complex spectrum of disorders and their treatment(s) are also highlighted.More than 70 diseases/disorders are associated with the progressive loss of memory and intellectual function known as dementia, although Alzheimer's disease (AD) is by far the most common cause. Current estimates suggest that more than four million Americans suffer from AD (Advisory Panel on Alzheimer's Disease, 1995). Although the diagnosis of dementia focuses on the clinical presentation of cognitive deficits, complex disturbances of behavior and emotion have been recognized as part of the disorder since Alois Alzheimer's original case report in 1907 describing the cerebral cortex and abnormal behaviors of a 55-yearold woman (Alzheimer, 1987). In contrast to the cognitive symptoms, which usually follow a welldescribed course of progressive decline, the occurrence and course of the noncognitive symptoms in dementia are less predictable (Tariot, 1994), developing at any stage during the disease process (Eisdorfer et al., 1992).There is a discrepancy between the labeling of symptoms by health care professionals and complaints by family members about their loved one's behavior. For example, dementia is generally defined by clinicians as progressive deterioration of cognitive abilities, however families of dementia patients often define the stages of illness with behavioral (noncognitive) markers. In fact, behavioral complications are a leading cause of institutionalization in persons with dementia (Knopman, Kitto, Deinard, & Heiring, 1988;Steele, Rovner, Chase, & Folstein, 1990).Disease progression is not measured simply by declining scores on the Mini-Mental State Exam or other clinical rating scales, but rather includes such symptoms as the amount of sleeplessness at night, the person's degree of agitation or psychosis, and the level of depressed mood. A key unanswered scientific question is how central these noncognitive behavioral symptoms are to

Behavioral and psychological symptoms of dementia and caregivers’ stress appraisals: Intra-individual stability and change over short-term observations

“…The term 'Behavioral and Psychological Symptoms of Dementia' (BPSD) has been used to subsume a multitude of common behavior problems associated with dementia, including problems with memory, disorientation, restlessness, mood, aggression, and sleep (Aneshensel, Pearlin, Mullan, Zarit, & Whitlatch, 1995;Burgio, 1996;Garand, Buckwalter, & Hall, 2000;Kirby & Lawlor, 1995;Pruchno & Resch, 1989;Swearer, 1994). While many aspects of caring for someone with dementia have been found to be stressful (Pearlin, Mullan, Semple, & Skaff, 1990), past research has found that behavior problems in dementia are more stressful for caregivers than dealing with the cognitive impairment or the need for assistance with activities of daily living Kinney & Stephens, 1989).…”

Different attitudes when handling aggressive behaviour in dementia--narratives from two caregiver groups

“…Behavioural and psychiatric symptoms of dementia includes: psychosis, depression, anxiety, euphoria, eating and sleeping disturbances, agitation, aggression, abnormal vocalization, wandering, over-activity, loss of sexual inhibition and apathy (Finkel et al, 1996). Garand et al, (2000) among others, describes aggressiveness as related to brain damage and premorbid personality. However, this perspective does not take into consideration that the person with dementia is a human being who has feelings, thoughts, and expectations.…”

Towards defining restlessness in individuals with dementia

“…We have identified four theoretical models that may have applicability to restlessness and which have been used previously to understand other behavioral symptoms and inform intervention development: (1) neurobiological/genetic framework (e.g., Cohen-Mansfield, 2000; Garand & Hall, 2000; Raskind & Peskind, 1994), (2) behavioral model (e.g., Teri, 1997), (3) reduced stress threshold model (Hall & Buckwalter, 1987; Smith, Gerdner, Hall, & Buckwalter, 2004), and (4) unmet needs model (e.g., Algase et al, 1996). …”

“…The neurobiological/genetic model postulates that behavioral symptoms are the result of changes in the brain that are associated with dementia (Cohen-Mansfield, 2000; Garand & Hall, 2000; Raskind & Peskind, 1994). However, not all restless-type behaviors appear to be attributable to neurobiological causes.…”

“…Further research is needed to elucidate the relationship between restless-type behaviors and neurological mechanisms. Regarding genetic contributions to behavioral symptoms, research suggests that familial Alzheimer’s disease (AD) – also known as early-onset AD – is associated with more pronounced behavioral symptoms than the more common late-onset AD (Garand & Hall, 2000). …”