Table of Contents
Definition of Cognitive Disorders
Cognitive disorders are a group of mental health disorders which predominantly affect learning, memory, perception and problem-solving. They result primarily from primary and secondary abnormalities of the central nervous system.
Four major kinds of cognitive disorders are:
- Delirium: It is characterized by reduced attention/awareness which develops over a short period of time and in a dramatic manner. Toxins and illnesses cause the condition. It is usually reversible.
- Dementia: Unlike delirium, dementia is a chronic and progressive loss of cognitive function, characterized by memory problems, confused thinking, and inability to concentrate. Common causes of dementia include infarction, HIV/AIDS, and Alzheimer’s disease.
- Amnesia: In this condition, a significant loss of memory occurs, but there is no loss of other cognitive functions as seen in dementia.
- Cognitive disorders not otherwise specified: In this kind, cognitive impairment may be due to a general medical condition or substance use.
Tests Performed to Assess Cognitive Function
Mini-mental Status Examination (MMSE)
- Short screening structured test to measure cognitive impairment
- Takes approximately 5—10 minutes and covers many cognitive functions
- Easy to establish the score and know the patient’s level of cognitive function.
- Not helpful for the uneducated as it includes language and mathematical testing
- For mild cognitive impairment, other tests need to be performed
- Questions are verbal; hence it is difficult to measure visuospatial and/or constructional praxis.
The test consists of 11 questions with 5 areas of cognitive function: orientation, registration, attention and calculation, recall, and language can be measured.
|What is the: Year, Season, Date, Day, and Month?
Where are we: State, Country
Town, Hospital, Floor?
|Registration||Name three objects and asks the patient to repeat
|Attention and calculation||Subtract 7 from 100 and then repeat from the result.
Alternative: spell 5 letter word – world, backward
|Recall||Ask the patient to repeat the names of the three objects learned from question 3||3 points|
|Language||Name a pencil and watch.
Repeat the following “No ifs, and, or buts”
Give a 3 stage command
Read and obey: Close Your Eyes
Write a sentence.
Copy the design shown.
Interpreting the Results of Tests Performed to Assess Cognitive Function
24—30: No cognitive impairment
18—23: Mild cognitive impairment
0—17: Severe cognitive impairment
Montreal Cognitive Assessment (MoCA)
It a brief screening test designed to detect cognitive impairment in elders.
- Accessible online and available in several languages
- A good test for an educated person who has only a memory impairment complaint
- A 30-point test which takes about 10 minutes
- Compared to MMSE, this test is more sensitive for the detection of mild cognitive impairment
- Assesses other cognitive domains, such as memory, language, attention, visuospatial and executive functions.
Thirty items assess these multiple cognitive domains:
- Short-term memory recall – 5 points
- Visuospatial abilities evaluated using a clock-drawing task – 3 points and a three-dimensional cube copy task – 1 point
- Executive functioning measured by an adaptation of Trail Making Test – 1 point
- Phonemic fluency – 1 point
- Verbal abstraction – 2 points
- Attention, concentration, and working memory measured using target detection – 1 point
- Serial subtraction – 3 points
- Digits forward – 1 point
- Digits backward – 1 point
- Language measured by confrontation naming of low-familiarity animals – 3 points
- Complex sentences repeated – 2 points
- Orientation to time and place evaluated – 6 points
Total possible score – 30 points
The score of 26 or above is considered normal
It consists of 2 components:
- 3-words recall test for memory where you score 1 point for each word recalled without cues. Score 0—3.
Scoring: 1 point for each word recalled without cues. Score 0—3.
Simple Decision Tree
Clock drawing where you score form 0—2 with :
- 2 points representing normal clock where a normal clock should include all numbers from 1—12 in the correct order and clockwise direction.
- 0 point representing abnormal clock (abnormal hands or missing numbers)..
Advantages of the Mini-Cog:
- Sensitive to measure dementia status
- Short testing time compared to MMSE
- Diagnostic value not limited by the subject’s education or language.
As a screening test, it does not substitute for a complete diagnostic workup.
Interpreting the Mini-Cog Score:
A mini-cog score can be obtained by adding recall and CDT scores.
- 0—2 points suggest possible impairment.
- 3—5 points suggest no impairment.