  With populations ageing, the number of people with dementia worldwide is
expected to triple to 152 million by 2050. Seventy percent of cases are due to
Alzheimer's disease (AD) pathology and there is a 10-20 year 'pre-clinical'
period before significant cognitive decline occurs. We urgently need, cost
effective, objective methods to detect AD, and other dementias, at an early
stage. Risk factor modification could prevent 40% of cases and drug trials
would have greater chances of success if participants are recruited at an
earlier stage. Currently, detection of dementia is largely by pen and paper
cognitive tests but these are time consuming and insensitive to pre-clinical
phases. Specialist brain scans and body fluid biomarkers can detect the
earliest stages of dementia but are too invasive or expensive for widespread
use. With the advancement of technology, Artificial Intelligence (AI) shows
promising results in assisting with detection of early-stage dementia. Existing
AI-aided methods and potential future research directions are reviewed and
discussed.
