Incidence And Course Of Dementia In People With Down's Syndrome: Findings From A Population‐Based Study

Abstract

The prevalence rate of Alzheimer's disease (AD) in people with Down's syndrome (DS) increases significantly with age. However, the nature of the early clinical presentation, course and incidence rates of dementia are uncertain. The aims of the present study were to investigate the characteristics of age-related clinical changes and incidence rates for dementia in a population-based sample of people with DS aged 30 years and older at the age of risk for dementia. A modified version of the Cambridge Examination for Mental Disorders of the Elderly informant interview was used to determine the extent and nature of changes in memory, personality, general mental functioning and daily living skill 18 months after a similar assessment At the time of the first assessment, the initial changes reported were predominately in behaviour and personality. At the second assessment, overall estimated incidence rates for frontal-like dementia were high (0.24), mainly in the younger groups, with incidence rates of AD, meeting both ICD-10 and DSM-IV criteria, of 0.04 predominately in the older groups. The present authors have hypothesized that the observed personality changes and the high estimated incidence rates of frontal-like dementia in the younger groups may indicate that functions served by the frontal lobes are the first to be compromised with the progressive development of Alzheimer-like neuropathology in people with DS.

Down's syndrome and dementia

“…A recent study of 285 people with Down's syndrome found a 13% prevalence of Alzheimer's disease (Tyrell et al, 2001). Age-related cognitive decline and frontal lobe dementia appear to be more prevalent in the younger age groups (30-49 years of age), and frontal lobe dementia appears to be more prevalent in those with more severe learning disability, but this needs to be confirmed by further studies (Holland et al, 2000). It is possible that early-onset cases present with more frontal symptoms and this may represent a different clinical subtype of Alzheimer's disease in Down's syndrome.…”

“…Deterioration in memory, learning and orientation tend to be the first signs, and these symptoms are often accompanied by increased dependence (Cosgrave et al, 2000). Personality change is often associated with early involvement of the frontal lobes (Holland et al, 2000). It has also been reported that Alzheimer's disease in Down's syndrome presents with a greater prevalence of low mood, excessive overactivity/ restlessness, disturbed sleep, excessive uncooperativeness and auditory hallucinations (Cooper & …”

Frontal Lobe Degeneration in Adults with Down Syndrome and Alzheimer's Disease: A Review

“…However, among individuals with DS and AD, a high prevalence of excessive agitation, sleep disorders, restlessness, and auditory hallucinations has been reported [19]. The results of cross-sectional and longitudinal studies suggest that changes in the personality and behavior of adults with DS can indicate the early stages of dementia prior or simultaneous to the onset of other typical AD symptoms such as cognitive decline [19,20,21,22,23]. Those initial alterations are comparable to the changes associated with frontotemporal dementia in the general population and are considered precursors of the development of AD in individuals with DS, indicating that the frontal and temporal lobes are the brain regions first affected in this population [23,24,25].…”

Infections and Acute Leukemia in Children with Down Syndrome

“…In different parts of the world, the incidence of DS varies from 0.3 to 3.4 per 1000 births, with a ratio of 1:1000 births being reported principally in America and Europe (Canfield et al, 2006;Hassold et al, 1996;Wahab et al, 2006;Webb et al, 2007). DS is associated with cardiovascular diseases; deficiencies of the digestive, immune, and endocrine systems; hematological problems; and also early onset of Alzheimer disease (Freeman et al, 2008;Holland et al, 2000;Linabery et al, 2008;Van Cleeve & Cohen, 2006;Wiseman et al, 2009). Compared to children without this syndrome, children with DS have ten-to twenty-fold higher risk of developing acute leukemia (AL) (Fong & Brodeur, 1987;Malinge et al, 2009;Ross et al, 2005a;Taub, 2001); it is estimated that approximately 1-2% will develop leukemia (Hasle et al, 2000;Malinge et al, 2009;Taub, 2001).…”