Dementia is a general term used to describe various symptoms of cognitive decline, such as forgetfulness. It is a symptom of several underlying brain diseases and disorders. Dementia is not a single disease in itself, but a general term to describe symptoms of impaired memory, communication and thinking.
Although the likelihood of having dementia increases with age, dementia is not a normal phenomenon of aging. Some figures on dementia
There are an estimated 47.5 million people with dementia worldwide.
a new case of dementia is diagnosed every 4 seconds
Dementia mainly affects older people, but is not part of the normal aging process.
Symptoms of dementia include memory loss, disorientation and mood changes. A person with dementia may experience any of the symptoms listed below, primarily due to memory loss.
Some symptoms they may notice themselves, others may only be noticed by caregivers or healthcare workers.
Possible symptoms of dementia:
– Loss of recent memory: a sign of this could be asking the same question repeatedly.
– Difficulty performing familiar tasks: for example, preparing a drink or a meal.
– Communication problems: language difficulties, forgetting simple words or using wrong words.
– Disorientation: getting lost on a previously familiar street, for example.
– Abstract thinking problems: for example, managing money.
– Loss of objects: forgetting the location of everyday objects such as keys or wallets, for example.
– Mood changes: sudden and unexplained changes in attitude or mood.
– Personality changes: becoming irritable, distrustful or fearful.
– Loss of initiative: loss of interest in undertaking something or going somewhere.
As the patient ages, the symptoms of late onset dementia tend to worsen.
The 4 stages of dementia
Sometimes dementia is roughly divided into four stages:
1 Mild cognitive impairment: characterized by general forgetfulness. It affects many people as they age, but only progresses to dementia for some of them.
2 Mild dementia: People with mild dementia have cognitive impairments that occasionally impact their daily lives. Symptoms include memory loss, confusion, personality changes, getting lost, and difficulty planning and completing tasks.
3 Moderate dementia: daily life becomes more difficult and the person may need more help. Symptoms are similar to those of mild dementia, but more marked. The person may need help with dressing and combing their hair. They may also exhibit significant personality changes, such as becoming suspicious or agitated for no reason. Sleep disturbances are also likely.
4 Severe dementia: at this stage, the symptoms have worsened considerably. There may be a loss of ability to communicate, and the person may need full-time care. Simple tasks, like sitting and holding your head up, become impossible. Bladder control may be lost.
Types of dementia
There are several types of dementia, including:
– Alzheimer’s disease is characterized by ‘plaques’ between dying brain cells and ‘tangles’ within cells (both due to protein abnormalities). The brain tissue of a person with Alzheimer’s disease has progressively fewer nerve cells and connections, and the overall size of the brain decreases.
– Dementia with Lewy bodies is a neurodegenerative condition linked to abnormal structures in the brain. The brain changes involve a protein called alpha-synuclein.
– Mixed dementia refers to a diagnosis of two or three types of dementia occurring together. For example, a person may have Alzheimer’s disease and vascular dementia at the same time.
– Parkinson’s disease is also marked by the presence of Lewy bodies. Although Parkinson’s disease is often thought of as a movement disorder, it can also lead to symptoms of dementia.
– Huntington’s disease is characterized by specific types of uncontrolled movements, but also includes dementia.
Other disorders that cause symptoms of dementia include:
– Frontotemporal dementia also known as Pick’s disease.
– Normal pressure hydrocephalus when excess cerebrospinal fluid builds up in the brain.
– Posterior cortical atrophy resembles changes seen in Alzheimer’s disease, but in a different part of the brain.
Main causes of dementia
Dementias can be caused by the death of brain cells, and neurodegenerative disease, the progressive death of brain cells that occurs over time, is associated with most dementias. However, it is not known whether it is dementia that causes brain cell death or whether it is brain cell death that causes dementia.
Besides progressive brain cell death, like that seen in Alzheimer’s disease, dementia can be caused by head trauma, stroke, or brain tumor, among other things.
Vascular dementia (also called multi-infarct dementia): This results from the death of brain cells caused by conditions such as cerebrovascular disease, for example a
Dementia can also be caused by:
Prion diseases – for example, CJD (Creutzfeldt-Jakob disease).
HIV infection: Exactly how the virus damages brain cells is not known, but it is known to occur.
Reversible factors: Some dementias can be treated by reversing the effects of underlying causes, including drug interactions, depression, vitamin deficiencies, and thyroid abnormalities.
Diagnosis of dementia
The first step in assessing memory performance and cognitive health consists of standard questions and tasks.
Research has shown that it is not possible to reliably diagnose dementia without using the standard tests below, completing them fully and noting all responses; however, the diagnosis also takes into account other factors.
Cognitive tests for dementia
Current dementia cognitive tests are widely used and have proven to be a reliable way to indicate dementia. They have changed little since their inception in the early 1970s. The short mental test score has ten questions, including:
What is your age ?
What time is it, to the nearest hour?
What is the year?
What’s your birthday ?
Each correct answer earns one point; a score of six points or less suggests cognitive impairment.
The second part of the test probes someone close to the patient and consists of six questions aimed at determining whether the patient:
- has become less able to remember recent events or conversations
- started having trouble finding the right words or using inappropriate words
- had difficulty managing money or medication
- needed more help to get around (for no reason, for example, an injury).
If the test does indeed suggest memory loss, then standard tests are recommended, including routine blood work and a brain scan.
Certain risk factors are known to be associated with dementia. However, age is the most important predictor. Other risk factors include:
– Smoking and alcohol consumption.
– Atherosclerosis (cardiovascular disease causing narrowing of the arteries).
– High levels of “bad” cholesterol (low density lipoproteins).
– Higher than average blood levels of homocysteine (a type of amino acid).
– physical inactivity
Burleigh E, Reeves I, McAlpine C, Davie J. (2001 July). Can doctors predict patients’ abbreviated mental test scores? Age and Aging. 31(4):303-6
Dementia: Hope through research. (2015, November 2)
Marshal F. Folstein, Susan E. Folstein, Paul R. McHugh. (1975, November). “Mini-mental state”: A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research. Pages 189–198
Philip A. DeFina, Rosemarie Scolaro Moser, Megan Glenn, Jonathan D. Lichtenstein, Jonathan Fellus. (2013). Alzheimer’s disease clinical and research update for health care practitioners. Journal of Aging Research. Volume 2013 (2013), Article ID 207178, 9 pages