New research by UCL and the University of Cambridge shows that
delirium may have long-lasting effects, including accelerating the dementia
‘Efforts to diagnose, prevent and treat delirium must be increased as targeting delirium could be a chance to delay or reduce dementia.’
It suggests that delirium is a strong predictor of new-onset
dementia and acceleration of existing cognitive decline.
The study is the first to show the multiplying effects of delirium
and dementia in patients.
is an acute brain dysfunction syndrome
that results in confusion and decreased awareness of the surrounding or
In delirium, the
brain does not get adequate oxygen and other essential nutrients. This leads to the build up of toxic chemicals in the brain.
Delirium is a major public health problem that affects 20% of the
hospitalized older patients. The onset of delirium is sudden beginning within a
few hours to days.
Delirium may be caused by one or a combination of factors like:
- Severe or chronic medical illness
- Changes in metabolic balance like
low sodium or low calcium
- Alcohol or drug withdrawal
The researcher team found that in people who are not known to have
dementia, episodes of delirium may also reveal dementia at its earliest stages.
Both delirium and dementia are important factors that contribute
to cognitive decline among the elderly.
Research states that 3 of 10 cases delirium are preventable and
treatable through dedicated geriatric care. Delirium interventions might reduce
at least some cognitive decline and dementia.
"If delirium is causing brain injury in the short and long-term,
then we must increase our efforts to diagnose, prevent and treat delirium.
Ultimately, targeting delirium could be a chance to delay or reduce dementia"
said Dr. Daniel Davis (MRC Unit for Lifelong Health and Aging at UCL), who led
the research while at the University of Cambridge.
For the study, scientists examined brain specimens in 987 people aged
65 and older from three European populations - in Finland, Cambridge and
Each individual's memory, thinking and experience of delirium had
been recorded for over 10 years towards the end of their life.
The research team found that memory changes were more prominent in
those patients who had both delirium and dementia associated changes when
compared to pathological abnormalities due to Alzheimer's and other forms of
Delirium when associated to the pathological processes of dementia
accelerates cognitive decline beyond that expected for delirium or the
pathological process itself.
Dr Davis said, "Unfortunately, most delirium cases go
unrecognized. In busy hospitals, a sudden change in confusion may not be
noticed by hospital staff. Patients can be transferred several times and staff
often switch over - it requires everyone to 'think delirium' and identify that
a patient's brain function has changed."
Clinicians need to be alert to older people's cognitive changes
during acute episodes and therefore support wider implementation of best
practice in delirium prevention.
If delirium prevention could lead to consequent prevention of
dementia, further research is needed to understand exactly how delirium
interacts with dementia and how this could be blocked.
The study is published in the journal JAMA Psychiatry
- Daniel Davis et al. Delirium accelerates cognitive decline in late life: a neuropathological study in 987 individuals from three population-based cohort studies. JAMA Psychiatry ; (2017) doi:10.1001/jamapsychiatry.2016.3423
- Delirium - (http://www.mayoclinic.org/diseases-conditions/delirium/basics/definition/con-20033982)
- Delirium - (https://medlineplus.gov/ency/article/000740.htm)