Age of onset and duration of dementia in people with down syndrome: Integration of 98 reported cases in the literature

✍ Scribed by Dr. V. P. Prasher; V. H. R. Krishnan

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 579 KB
• Volume: 8
• Category: Article
• ISSN: 0885-6230
• DOI: 10.1002/gps.930081105

✦ Synopsis

The published case reports of 98 people with Down Syndrome were studied with respect to the age of onset and duration of clinically diagnosed dementia. The incidence of dementia was unimodal, increasing rapidly from 40 years to a peak of 30% incidence in the fifth decade of life, followed by a further rapid decline. Females with Down syndrome had an earlier onset. Duration of dementia decreased with increasing age of onset for both males and females.

KEY woms-Down syndrome, dementia, age of onset, duration.

The true prevalence rates of dementia in the nonmentally handicapped population are unknown, in particular for individuals with mild mental impairment. Hofman et al. (1991) recently reported the findings of the reanalysis of original data from 23 European datasets investigating prevalence of dementia in the general population, of which 12 were selected for comparison. The authors found that the overall prevalences for the 5-year age groups from 60 to 94 years were 1 . O, 1.4, 4.1, 5.7, 13.0,21.6 and 32.2%0, respectively. The prevalences were found to nearly double with every 5 years of increase in age. Similar findings have been reported by other researchers .

Although it is well established that the prevalence of dementia increases with age , whether there is a relative excess of Alzheimer-type dementia among women still remains controversial. Several studies report an increase in females ), although Hofman et al. (1991) found the prevalence to be higher only in woman aged 75 years or over, the prevalence of dementia being slightly higher in men under this age.