The view of cognitive impairment in elderly individuals has evolved over the centuries, from a normal inevitable part of aging, through demonic possession and hardening of blood vessels, to Alzheimer disease. As Fotuhi et al. discuss in this article, individuals over 80 years of age rarely have 'pure Alzheimer disease' or 'pure vascular dementia'. The authors present a new framework, known as the dynamic polygon hypothesis, which reflects the complex interplay of factors that contribute to cognitive impairment in the oldest old.
- Majid Fotuhi
- Vladimir Hachinski
- Peter J. Whitehouse
