Dementia has recently drawn much attention due to Prof. Charles Kao, the winner of the Nobel Prize for physics and the father of fibre optics, who is also suffering from dementia. Alzheimer’s disease, the most common type of dementia, accounts for more than 70% of dementia patients. Old age does not necessarily lead to dementia. However, elders are at a higher risk of getting the disorder. In Hong Kong, it is estimated that 5 to 8 out of every 100 persons over 65 years of age have dementia. Moreover, there are 20-30% people over 80 years old have dementia of different extents.

Although there is no cure for dementia at present, people with dementia can maintain their brain functions and slow down degeneration through medications if their symptoms are detected early. Since people with dementia will lose memory gradually to the extent that they even forget their own names, they have great difficulties in taking care of themselves. They need support and care from family members to cope with the disease together.

(Special thanks to Dr. K H LAU, Associate Consultant, Department of Psychiatry, Queen Mary Hospital for reviewing the information of this page.)


Dementia is a kind of brain disorder. Brain cells gradually die as people grow older. However, brain cells of people with dementia die quickly and their brains will shrink, causing severe deterioration of brain functions.  Dementia patients may not only become forgetful, but also have problems with understanding, language, learning, calculation and judgment. Their personalities and behaviors may change too.

There are three main categories of dementia:

  • Alzheimer's disease (AD) is the most common type of dementia. The causes of AD are not known yet and the degeneration is progressive.
  • Vascular dementia is triggered by strokes and cerebro-vascular problems that cause damage to the brain. Degeneration can come on suddenly and fast. 20% of dementia patients are in this category.
  • Other kinds of dementia may be caused by inadequate nutrition, hypothyroidism and drug poisoning. In these cases, patients can alleviate their conditions through medications. Some dementias may be caused by other disorders such as Parkinson's disease and AIDS, etc.
  • Age:Dementia generally occurs in people over 65 years of age. The risk of dementia increases significantly with age.
  • Family history: People with a family history of dementia are at greater risk of developing it.
  • Sex: Dementia is more common in women, partly because women live longer.
  • Lifestyle: People with high blood pressure, high cholesterol levels or diabetes, etc., are at increased risk of developing dementia if they do not take steps to control their conditions.
  • Cognitive impairment: People with cognitive impairment due to various kinds of disorders or other factors are at higher risk of developing dementia in later years.
  • Education level: Studies have shown that people with lower education level have a greater risk of getting dementia. It might be that highly educated people have more mental exercises, which protect the brain from degeneration.

There is no known way to prevent Alzheimer's disease. However, the following steps can help reduce the risks of getting the disease and slow down brain degeneration in the elders:

- Keep mentally active
Mentally stimulating activities, such as reading and playing chess, may protect you from dementia or increase your ability to cope with the changes associated with dementia. It seems that playing mahjong is a mentally stimulating activity. However, if you have been playing mahjong ever since you were young, it has become a reflex rather than a mental exercise and may not be that effective in preventing dementia.

-  Maintain a healthy diet
A balanced diet can maintain healthy blood vessels, reduce the chance of high blood pressure and high cholesterol levels, and thus lower the risk for vascular dementia. Studies show that a diet with less meat but rich in fish, vegetables, and olive oil can greatly reduce the risk of dementia.

- Get enough vitamins B12, C and E
Vitamin B12 deficiency may lead to dementia. If you do not eat much fish, meat, eggs or milk, you should get supplements of vitamin B12. Vitamins C & E are antioxidants which may protect neurons and blood vessels to prevent dementia.

- Exercise regularly
Besides keeping mentally active, regular exercise can also help reduce the risk of dementia.

- Avoid smoking and alcohol abuse
Quit these bad habits to prevent damages to blood vessels and other body organs.


The underlying causes of dementia have not yet been identified. Studies have shown that two types of brain cell change are common in people with dementia. These include plaques (clumps of a normally harmless protein called beta-amyloid) and tangles (fibrous tangles made up of an abnormal protein called tau protein). Both of them can lead to brain cell death. However, the causes for these conditions are still unknown at present.

Besides, dementia may occur when blood vessels in the brain are damaged, either being occluded or reputured that prevent blood from supplying to the brain. People who have mild strokes (small in size or temporary) may not recognize that their blood vessels and brain cells are already damaged and have an increased risk of dementia.

Some dementias, such as those caused by vitamin B12 deficiency due to being vegetarian for a long time, may be reversible with treatment.  


We generally believe that memory decreases with age; hence dementia may go unrecognized in the early stages of the disease. If you find a family member or friend who has two of the following symptoms, try to get him or her to go to see a doctor as soon as possible. If necessary, the doctor will refer him or her to a specialist for further examination.

Symptoms of dementia include:  

  • Short-term memory loss and frequently forgetting conversations or appointments that affect daily activity or working ability
  • Difficulty in performing familiar tasks
  • Problems with language, difficulty in communicating with others
  • Poor judgment
  • Time and place disorientation. Confusion about time, date or place
  • Problems with thinking and calculation
  • Changes in mood and behavior
  • Loss of initiative
  • Misplacing belongings
  • Personality changes

To rule out the possibility of other conditions that could cause similar symptoms, doctors will do a number of tests to diagnose dementia on top of a detailed history taking and mental state examination.

  • Blood tests: to help rule out other disorders such as hypothyroidism or vitamin B12 deficiency, etc.
  • Behavioral evaluation and cognitive test: A number of structured tests measuring memory and mental skills to determine whether dementia is present.
  • MRI (magnetic resonance imaging) scan: It uses a magnetic field and radio waves to create detailed images of the brain to help identify any size and structural changes of the brain and other problems such as blood clots or tumors in the brain.
  • PET (Positron emission tomography) scan: It is a kind of imaging test that can detect abnormalities of beta-amyloid in the brain. It involves injecting a small amount of radioactive substance (a tracer) into the vein. The tracer travels to the brain to detect the beta-amyloid. It helps to evaluate the severity of the condition and the patient’s response to the medications.

There is currently no definite cure for dementia. However, there are two kinds of medications that can help delay brain cell death and slow down cognitive decline.

  • Cholinesterase inhibitors
    These drugs include donepezil, rivastigmine and galantamine They work by boosting levels of a kind of neurotransmitter involved in brain function. They seem to be of most benefit to people in the early to moderate stages of dementia. Side effects can include diarrhea, nausea and vomiting.
  • Memantine
    It protects the brain cells against abnormal activity of glutamate, another kind of neurotransmitter involved in brain function. It is believed that high levels of glutamate may cause damage to brain cells. Memantine helps to slow down the deterioration of dementia for people with moderate or severe grade by regulating the activity of glutamate. Sometimes doctors may prescribe memantine along with a cholinesterase inhibitor to get better results. Side effects include dizziness and anxiety.

Doctors may also prescribe medications to help improve symptoms such as insomnia, anxiety, depression, hallucination and delusion, etc.

Besides, there are other non-drug therapies that can be effective for people with dementia. These include reality orientation, cognitive training, multi-sensory stimulation, psychological and behavioral therapies. They can improve patients' mood and behavior, enhance their remaining functions and skills and help them maintain independence in daily life.


People with dementia suffer from gradual degeneration of cognitive function, memory, thinking and language abilities. Eventually they will be unable to take care of themselves and finally be totally dependent and even bedridden. They differ in the patterns of problems they experience and in the speed with which their abilities deteriorate. Features of dementia are generally classified into three stages. The early stage may last around 3 years and the moderate stage lasts for another 3 years.

Symptoms in the moderate stage include:

  • Slow response
  • Decreased analytical ability
  • Severe memory loss, being unable to take care of oneself and dependent on others
  • Problems with acquiring new knowledge and skills
  • Language problems
  • Being emotional, having agitation and psychiatric problems such as hallucinations or delusions
  • Wandering around streets, being confused about day and night

People with severe dementia may:

  • Be unable to understand or use speech
  • Be unable to recognize family members
  • Be unable to perform basic activities of daily living such as eating and bathing
  • Lose bowel and bladder control
  • Have difficulties in swallowing, walking or even be bedridden

Dementia patients need support and care from their family members. The medical teams will guide the family members to take care of the patients. There are patients groups and charity organizations that provide training courses for family members. Here are some tips for taking care of people with dementia:

(A) Daily care

  • Set a timetable for the patient to avoid him/her from being confused about things due to memory loss. For example, fix meal time and activity schedule. Try to avoid drastic activities at night.

  • Choose things that the patient likes, such as clothes and food.

  • Help the patient to keep personal hygiene and be tidy. Encourage him/her to do simple things like getting dressed and brushing teeth. Assist him/her only when it is necessary.
  • Choose clothes that the patient can easily put on by himself/herself, such as those that have few buttons.Put signs on cabinets or drawers so that he/she can get things out easily.

(B) Environment

  • Use large and clear signs to help the patient to recognize place and time, such as large clocks and large calendars.
  • Place a lamp at home or at the bedside, so that he/she won't feel anxious when he/she wakes up at midnight. It can also prevent him/her from tripping over.
    • Try not to change the home environment, especially bathroom, toilet and kitchen.
      • Do not move home, because new environment can cause confusion and fear.

      (C) Communication techniques

      • Speak slowly to the patient. Use short and direct sentences. Only say one key point in one sentence. Don't make it complicated.
        • Ask simple questions. Let the patient just answer yes or no. Give him/her enough time to think about the answer.
          • Repeat the question when he/she forgets it.
            • When he/she cannot answer immediately, be patient and encourage him/her to express his/her opinions and feelings. If he/she still can't answer, don't force him/her to. Try again next time.
              • Use body languages. Have eye contacts when you speak or listen to the patient. Give response such as nodding your head.


              • When the patient refuses to participate in activities, don't force him/her to.
                • If you want the patient to do things that he/she is not familiar with or go to a strange place, give him/her enough time to adapt to the new environment, or stay with him/her until he/she gets familiar with it.

                Providing care for a person with dementia is physically and emotionally demanding. When your family member no longer recognizes you and can't remember the times you spent together, you of course feel distressed.   While you learn how to take care of him/her, you can join a support group, share your feelings and experience with the others and cope with the challenge together.

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