What is dementia?
The WHO defines dementia as a spectrum of disorders that are associated with difficulties in memory, thinking, reasoning and ability to manage everyday activities independently.
Difficulties with social behaviour, attention, executive function, language and learning can also occur.
Executive function includes ability to plan, exhibit self-control, focus, solve problems, regulate emotions, juggle and coordinate multiple activities etc.
What are the types of dementia?
There are 5 main types of dementia though a person may have features from more than one type.
How many people are estimated to have dementia?
In 2020, WHO estimated that there were 55 million people with dementia, this number was expected to rise to 78 million by 2030, with the majority of these persons being in developing countries. Approximately 10 million cases are diagnosed each year, which is an estimated 1 person every 3.2 seconds.
Alzheimer’s disease is the most common type of dementia, accounting for 60 to 70 % of cases. It is related to the build up of a certain type of protein (amyloid and tau) in the brain causing damage to brain tissue.
Image from M.I.N.D (Medical institute of neuropsychological disease webpage- mindclinic.org/media-center/news/disease- Information from the World Alzheimer Report 2015 entitled: “The Global Impact of Dementia: An analysis of prevalence, incidence, cost and trends” published by Alzheimer’s Disease International (ADI), London in August 2015.
What are the advantages of early detection of dementia?
Below is information taken from a table from the Alzheimer’s Association website-alz.org/clinicalcare. Article- Differential diagnosis of dementia.
Differentiating between common forms of dementia
|
Alzheimer’s Dementia |
Vascular Dementia |
Dementia with Lewy |
Parkinson’s Disease |
Frontotemporal |
|
| Progression of the disease | Subtle onset and gradual progression |
Caused by clot or bleeding in the brain- progression varies depending on the location and extent May be a step |
Subtle onset and gradual progression |
Subtle onset with gradual progression |
Subtle onset with gradual progression |
| How it presents | Early in the disease there is memory loss and difficulty learning Later language |
There is a timed link between stroke and onset of symptoms |
May present with REM sleep disorder, visual hallucinations, shifting levels of cognition and ability to function. Cognitive Not as commonly |
Cognitive decline occurs later in the illness, usually more than a year after movement symptoms. The cognitive |
There are 2 variants/types- behavioural and language. Behavioural Language |
| What are the other symptoms, signs and features? |
There are other possible behaviour and psychological symptoms: Early: Moderate/severe: Late: |
There may be a history of stroke or transient ischemic attack (minor stroke). Changes in mood Slow walking In some cases, |
Nearly half have sensitivity to antipsychotic medications Falls, fainting, |
Apathy (not caring about anything), depression, anxiety, delusions, hallucinations, REM sleep disorder, change in personality, excessive daytime sleepiness |
Extrapyramidal symptoms occur in late disease: Tremors, rigidity, slow movement tongue protrusion, lip smacking, excess salivation Majority |
| What factors increase the risk of this type of dementia? |
Increasing age and genetics (family history, down’s syndrome), being inactive, smoking, being mentally inactive, high blood pressure, diabetes, poor diet, traumatic head injury, reduced social interaction |
High blood pressure, high cholesterol, diabetes, smoking, atrial fibrillation |
Genetic risk | Predictors include: age, male sex, more motor symptoms, hallucinations, REM sleep disorder, high blood pressure, smoking |
Up to 40% are familiar Brief learning/reasoning /thinking- may |
| Are there investigations that can be done? |
imaging tests (MRI, CT, PET) ,tests of cerebrospinal fluid. Blood tests |
none | none | none | none |
