What is Cognitive Function?

What is Major Neurocognitive Disorder?

Ten SIGNS of Major Neurocognitive Disorder

What is Mild Cognitive Impairment or Mild Neurocognitive Disorder?

If suspicious of Mild Cognitive Impairment, what should be done?

Cognitive Behavioural Checklist

Intervention of Cognitive Impairment

 

What is Cognitive Function?

Cognitive function pertains to the intellectual processes that enable people to attend to a task, reason, and solve problems. It involves the acquisition and use of knowledge, thinking process and the ability to process, store, retrieve and manipulate information.

Cognitive function is composed of the following performance components:

  • Level of Arousal
    - Demonstrating alertness and responsiveness to environmental stimuli
  • Orientation
    - Identifying person, place, time, and situation
  • Recognition
    - Identifying familiar faces, objects and other previously presented materials
  • Attention
    - Selectively concentrating on one thing while deliberately ignoring other things
  • Initiation of Activity
    - Starting a task over time
  • Termination of Activity
    - Stopping a physical or mental activity
  • Memory
    - Recalling information after brief or long periods of time
  • Sequencing
    - Placing information, concepts, and actions in order
  • Categorization
    - Identifying similarities of and differences between pieces of environmental information
  • Concept Formation
    - Organizing a variety of information to form thoughts and ideas
  • Visual-Spatial Construction
    - Mentally manipulating the position of objects in various relationships
  • Problem Solving
    - Recognizing and defining a problem, identifying alternative plans, selecting a plan, organizing steps and implementing a plan, evaluating the outcome
  • Decision Making
    - Selecting a course of action from multiple alternatives
  • Judgement
    - Considering multiple factors and deriving sensible conclusions or decisions
  • Learning
    - Acquiring new concepts and behaviours
  • Language
    - Using sounds, words, patterns, etc to communicate thoughts and feelings or reason
  • Reasoning
    - Using reason to derive a conclusion from certain premises.
  • Generalization
    - Applying previously learned concepts and behaviors to a variety of new situations
 

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What is Major Neurocognitive Disorder?

Major Neurocognitive Disorder (NCD), known previously as dementia, is a clinical state characterized by loss of function in multiple cognitive domains, caused by ageing of the brain or neurological diseases. NCD can affect adults of any age, although it is more likely to occur in the later years. According to a local study, there is 1 in every 10 suffered from dementia in people with age over 70. The prevalence increases to one-third for those with age over 851. The symptoms include gradual loss of memory and other intellectual abilities (e.g. comprehension, language, learning, calculation and decision making). Some patients also have changes in mood, behaviour or sensory functions.

Types of NCD

  • NCD due to Alzheimer's Disease
  • Vascular NCD
  • Frontotemporal NCD
  • NCD with Lewy Bodies
  • NCD due to secondary causes


NCD due to Alzheimer's Disease
Alzheimer's Disease is the most common form of NCD. In Hong Kong, it accounts for 64.6% of elderly with NCD.2
The cause of the disease is unclear in most of the patients. The causes include changes or deterioration in certain areas of the brain, genetic factors and family history. In brain autopsy of patients with Alzheimer's Disease, neurofibrillary tangles and beta amyloid plagues, which cause nerve cell degeneration in the brain's nucleus with reduced level of the neurotransmitter acetylcholine, are observed.
Alzheimer's Disease is a progressive disease. Patients with Alzheimer's Disease will progressively have impairment in memory, comprehension, language, learning, calculation, judgement, etc. They also experience increasing difficulty in daily living, such as bathing, toileting, personal hygiene and communication, and require more prompting and assistance during the course of the disease.


Vascular NCD
Vascular NCD is the second most common form. It accounts for 29.3% of the elderly with NCD in Hong Kong.2
It is caused by cerebrovascular diseases which lead to impaired blood supply to the brain, causing acceleration of brain cell ageing and cell death. The progression of the disease is stepwise. Activities of daily living, cognition, memory and communication skills are usually affected.

Frontotemporal NCD
Frontotemporal NCD is a degenerative condition of the brain. The areas of the brain mainly affected are the frontal and anterior temporal lobes. In the early stage, memory problem is not prominent in patients with Frontotemporal NCD. In later stage, they are usually presented with prominent memory and behavioural problems, for instance, loss of inhibition, neglect of social rules, reduced flexibility and agitation. Frontotemporal NCD is rare and occurs predominantly after the age of 40 and usually before the age of 65. The prognosis of this disease is poor, owing to the prominent symptoms and behavioral problems.

NCD with Lewy Bodies
Lewy bodies are microscopic protein deposits found in the damaged regions within the brains of people with symptoms of Parkinson's disease. However, they are found widespread throughout the brain of patients diagnosed NCD with Lewy Bodies. Apart from memory loss and deterioration of cognitive function, patients diagnosed NCD with Lewy Bodies show symptoms of Parkinson's Disease, such as hand tremour, slowed movement and rigidity. In addition, most of these patients have psychotic symptoms, especially visual hallucination. The course of this illness is fluctuating. Treatment is directed at managing the signs and symptoms of the disease. However, patients diagnosed NCD with Lewy Bodies are sensitive to the extrapyramidal side effects of antipsychotic medications.

NCD due to secondary causes
It refers to the symptoms of NCD caused by other diseases, including:

  • Deficiency of Vitamin B12 and folic acid
  • Genetic or metabolic disease (e.g. hypothyroidism)
  • Toxic or traumatic injury
  • Depressive mood

(Reference: "Beautiful World of Dementia" by The Hong Kong Society for the Aged)

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Ten SIGNS of Major Neurocognitive Disorder

  • Deteriorated short-term memory, which affects performance in daily living or work
  • Increased forgetfulness about where to put one's belongings
  • Difficulty in performing familiar tasks
  • Disorientation to time, place or person
  • Loss of initiative and energy
  • Difficulty in expression and comprehension
  • Difficulty with decision-making
  • Problem in thinking process/calculation
  • Fluctuation in mood and behaviour
  • Personality change

(Reference: "Ten Signs" by Hong Kong Alzheimer's Disease Association)

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What is Mild Cognitive Impairment or Mild Neurocognitive Disorder?

Mild Cognitive Impairment or Mild Neurocognitive Disorder is a term generally referring to persons who do not fulfill criteria for Major NCD, but who exhibit some form of cognitive impairment. It is usually regarded as "normal ageing" or "transitional but progressively degenerative cognitive phase that precedes the onset of Major NCD". Patients with Mild Cognitive Impairment usually have memory problems, which have no significant influence on performance in daily living. However, patients with Mild Cognitive Impairment would experience increased difficulty in managing complex tasks (e.g. financial management). According to the study of Petersen3, 10% to 15% of patients with Mild Cognitive Impairment would progress to Dementia.

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If suspicious of Mild Cognitive Impairment, what should be done?

The findings of recent research related to cognitive impairment in the elderly suggest that" Early Detection, Early Intervention" could slow down the progression of cognitive impairment and its influence on functional independence. Medical consultation should be sought if Mild Cognitive Impairment is suspected.

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Cognitive Behavioural Checklist

Does the elderly have the following condition in the recent two months?

  Reported by the Elderly Reported by Relative(s)/ Staff
1. Get lost in familiar places
    
2. Forget important festivals/appointment (e.g. Medical follow-up)    
3. Disoriented to Time (Day/Month/Year)    
4. Confused about day and night    
5. Disoriented to Place    
6. Unable to recognize familiar persons    
7. Word-finding/Naming problem    
8. Repeated questioning    
9. Increased forgetfulness about recent events    
10. Increased forgetfulness about where one put his/her belongings    
11. Forget to turn off stove/water tap    
12. Reduced speech    
13. Difficult in expression    
14. Difficult in comprehension    
15. Deteriorated judgment    
16. Difficult in simple calculation    
17. Difficult in money management    
18. Deteriorated organization skills    
19. Lack of initiation/motivation    
20. Become passive & require prompting to participate in activity    
21. Deteriorated performance in basic self-care (e.g. buttoning)    
22. Reduced awareness on own personal hygiene and appearance    
23. Mood problem (e.g.: Easily agitated/ Cried/ Uncooperative)    
24. Personality change (e.g.: Socially withdrawn/ Apathy)    
25. Always complained others for stealing one's belongings    
26. Deteriorated sleep pattern/quality    
27. Feeding habit change (e.g. picky on food, oral intake refusal/ over-eating)    
28. Hoarding (e.g.: collecting garbage)    
29. Hiding things    
30. Restless    
31. Wandering    
32. Others:    

Download Cognitive Behavioural Checklist

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Intervention of Cognitive Impairment

Intervention of cognitive impairment includes:

  • Pharmamacological Intervention
  • Non-pharmacolocial Intervention

Pharmamacological Intervention
Pharmacological treatment is often the central intervention used to improve symptoms or delay the progression of dementia syndromes. However, the efficacy of such intervention is still to be proven. The common medication includes:

  • Acetylcholinesterase Inhibitors
  • Estrogen
  • Vitamin E
  • Other Anti-Oxidants

Non-pharmacolocial Intervention
Non-pharmacological intervention mainly consists of three apsects: reduction of cardiovascular disease risk factors, cognitive stimulation and training, and psychological support for the patients.

1. Reduction of cardiovascular disease risk factors

  • Regular aerobic exercise
  • Balanced and healthy diet
  • Avoid smoking
  • Avoid alchoholism, etc.

2. Cognitive stimulation and training

  • Cognitive training
  • Memory aids/strategies
  • Increase cognitive activity and stimulation
  • Increase participation in meaningful activities

3. Psychological support

  • To combat with the confronting problems and make appropriate adaptation
  • To ventilate emotions

 

Other common interventions include:

  • Reminiscence
  • Reality Orientation
  • Validation Therapy
  • Multi-sensory Stimulation

 

The misconception of elderly towards memory and factors affecting the memory process should not be overlooked.

1. Misconception of elderly towards memory

  • Over-generalization
  • Exaggeration of negative conditions
  • Unrealistic expectations
  • Keen on comparing with others
  • Self-criticism

2. Factors affecting memory process

  • Anxiety and stress
  • Unstructured life routine
  • Negative thoughts
  • Inattention (somatic discomfort, lack of interest)
  • Disturbing or over-stimulating environment

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Reference

1. Lam et al. (2008). Prevalence of very mild and mild dementia in community-dwelling older Chinese people in Hong Kong. International Psychogeriatrics, 20(1), 135-148.

2. Chiu et al. (1998) Prevalence of dementia in Chinese elderly in Hong Kong . Neurology 50(4): 1002-1009.

3. Petersen RC. Conceptual overview. IN: Petersen RD, ed. Mild Cognitive Impairment: Again to Alzheimer's Disease. New York: Oxford University Press, 2003:1-14.