Delirium Could Pave Way for Late Life Dementia

Delirium in the presence of the pathological processes of dementia is associated with accelerated cognitive decline.

Highlights

Delirium is a common condition that results in confused thinking and decreased awareness of the environment.
Though delirium affects a quarter of the hospitalized older patients most of the time, it goes unrecognized.
New findings show that delirium may accelerate the long-term dementia-related memory decline.

Dementia is one of the long-lasting consequences of delirium.

New research by UCL and the University of Cambridge shows that delirium may have long-lasting effects, including accelerating the dementia process.

Delirium - Types, Causes, Symptoms, Signs, Diagnosis, Treatment
Delirium is a sudden disturbance in mental function that causes confusion and decreased awareness of one’s environment. It is classified into three subtypes – hyperactive, hypoactive and mixed.

‘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.

Delirium

Delirium is an acute brain dysfunction syndrome that results in confusion and decreased awareness of the surrounding or disorientation.

ICU Delirium - Causes, Symptoms, Diagnosis, Treatment
ICU delirium is the most dreaded and least diagnosed complication of an illness which requires treatment in the critical care unit.

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.

Dementia - Types, Causes, Symptoms, Diagnosis, Treatment
Dementia has become a very big concern as we have an aging population across the world. Dementia is also terrifying to us because of its disturbing symptoms and limited treatment options.

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
Medication
Infection
Surgery
Alcohol or drug withdrawal
Fever
Dehydration

Study

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.

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Alzheimer's disease is a progressive neurodegenerative disease affecting memory and thinking and making the person increasingly dependent on others.

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 UK-wide.

Each individual's memory, thinking and experience of delirium had been recorded for over 10 years towards the end of their life.

Findings

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 dementia.

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.

References:

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)

Source-Medindia