Dementia comes from a Latin word "Demens" which means "Absence of mind" chronic impairment of thinking that affects a persons ability to function in a social or occupational setting. The impairment is severe enough to interfere with the patient's ability to perform routine activities.


According to WHO:


Dementia is a syndrome, usually of a chronic or progressive nature, in which there is deterioration in cognitive function beyond what might be expected from normal aging. It affects memory, thinking, orientation, comprehension, calculating, learning capacity, language, and judgment. Consciousness is not affected. The impairment in cognitive function is commonly accompanied and occasionally preceded, by deterioration in emotional control, social behavior, or motivation.


Dementia is not a specific disease. It's an overall term that describes a group of symptoms associated with a decline in memory or other thinking skills severe to reduce a person's ability to perform everyday activities. Alzheimer's disease accounts for 60 to 80% of cases. Vascular dementia, which occurs after a stroke, is the second most common dementia type. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies. Dementia is often incorrectly referred to as senility or senile dementia which reflects the formerly widespread but incorrect belief that serious mental decline is a normal part of aging.


Dementia is not a specific disease. It is a descriptive term for a collection of symptoms that can be caused by a number of disorders that affect the brain. A progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal aging. Areas particularly affected include memory, attention, judgment, language, and problem solving, madness or insanity. Alzheimer's disease international estimates that are currently 30 million people with dementia in the world with 4.6 million new cases annually. The number of people affected will over 100 million by 2050.


The age group most commonly affected by this illness is 60 and over still, there is some risk group that is not age-dependent, such as people that suffer from high blood pressure, smokers high cholesterol patients and so on. Dementia is a brain disorder, beings after the age of 60 that seriously affects a person's ability to carry out daily activities. It begins slowly, involving the parts o the brain that control thought, memory & language. People with AD may have trouble remembering recent events, name of people.

Over times symptoms get worse and the patient might have trouble in speaking, reading & writing. They may forget how to brush their teeth or comb their hair, become anxious or aggressive, and wander away from home.


Causes:


Dementia is caused by damage to brain cells, this dan-mages interferes with the ability of brain cells to communicate with each other. When brain cells can not communicate normally, thinking, behavior and feeling can be affected. The brain has many distinct regions, each of which is responsible for different function (for example, memory, judgment, and movement). When cells in a particular region are damaged, that region cannot out its functions normally.



Causes divided into primary and secondary causes.







Primary Causes:


- Alzheimer's disease:

Is the most common form of dementia, and the disease most people associate with memory loss. Usually diagnosed after age 80 and is uncommon in people under the age of 65.


-Vascular dementia:

Occurs when small strokes or brain lesions impair blood flow to the brain. It is the cause of 20% of dementia cases, making it the second most common cause after Alzheimer's disease.


- Pick's Disease:

Symptoms are often hard to distinguish from Alzheimer's disease. Pick's disease damages nerve cells in the brains frontal and temporal lobes. Nerve cells affected by Pick's disease weaken and eventually die.


-Huntington's disease:

Is a genetically inherited neurological disease that can dementia. Huntington disease causes behavioral changes and chorea. The usual age of Huntington's disease onset is between forty and sixty years old.


- Parkinson's disease:

Is a progressive neurological disease that affects movement and muscle control. Symptoms of Parkinson's disease include tremors, balance problems, difficulty walking, and a rigid posture.


-Lewy- body dementia:

Related to Alzheimer's disease. The cause is the presence of abnormal substances called Lewy-body in parts of the brain such as cortex and brain stem. Lewy body dementia causes classical dementia symptoms, including memory loss. The disease can also cause hallucinations, depression, and paranoia.


Secondary causes:


Dementia like symptoms can develop as a result of an underlying condition can be treated, the symptoms will generally improve. The following are some of the common secondary causes that can lead to dementia.


-Alcohol Dementia and substance abuse:

Alcohol abuse can lead to symptoms of dementia. The long term toxic effects of alcohol on the brain are enough to cause it. Symptoms can often be improved by abstaining from alcohol.


-Infections diseases:

A number of infections that affect the central nervous system have been known to cause dementia symptoms, including HIV, meningitis, and encephalitis.


Medication:

As people age, they tend to require more medication for their health. Many of the medications include dementia symptoms as aside effect. The list of medications is incredibly long and includes such common medication as anti-diarrhea medication, anti-epileptic medications, antihistamines, cold and flu medication, sleeping pills, tricyclic antidepressants.


Pseudo Dementia:

Depression can result in dementia symptoms, including memory loss and a lack of motivation. Elderly people dealing with health problems, the loss of spouse, or loneliness are particularly susceptible to depression. Treating depression often result in the reversal of dementia symptoms.


Metabolic disorders:

Metabolic disorders can also symptoms of dementia. These disorders include cortisol hormone imbalances, diabetes, electrolyte levels, kidney failure, liver diseases, and thyroid disorders.


Wernicke- Korsakoff syndrome:

It results from a deficiency in thiamine (Vitamin B1) and is often due to chronic, severe alcoholism. It can also result from general malnutrition, eating disorders, or the effects of chemotherapy. Dementia due to Wernicke- Korsakoff syndrome involves confusion, apathy, hallucination, communication problems, and severe memory impairment.


Brain Tumors:

Brain tumors put pressure on and damage the surrounding brain tissue. A brain tumor can cause a number of symptoms, including dementia. The tumor may originate in the brain or may have spread to the brain from other organs.


Signs and symptoms:



Dementia affects each person in a different way, depending upon the impact of the disease and the person before becoming ill. The signs and symptoms linked to dementia can be understood in three stages.


Early-stage:

The early stage of dementia is often overlooked because the onset is gradual. Common symptoms include:

- Forgetfulness

- Losing track of the time

- Becoming lost in familiar places.


Middle stage:

As dementia progresses to the middle stage, the signs and symptoms become and more restricting. These include:

- Becoming forgetful of recent events and people's names

- Becoming lost at home

- Having increasing difficulty with communication

- Needing help with personal care

- Experiencing behavior changes, including wandering and repeated questioning.


Late-stage:

The late stage of dementia is one of near-total dependence and inactivity. Memory disturbances are serious and the physical signs and symptoms become more obvious. Symptoms include:

- Becoming unaware of the time and place

- Having difficulty recognizing relatives and friends

- Having an increasing need for assisted self-care

- Having difficulty walking

- Experiencing behavior changes that may escalate and including aggression.


Handling Money:

Trouble remembering simple words, often dementia sufferers will substitute inappropriate words without realizing.


Common forms of dementia:

There are many different forms of dementia. Alzheimer disease is the most common form and may contribute to 60-70% of cases. Other major forms include vascular dementia, dementia with Lewy bodies, and a group of diseases that contribute to frontotemporal dementia. The boundaries between different forms of dementia are indistinct and mixed forms often co-exist.


Rates of dementia:

Worldwide, around 50 million people have dementia, with nearly 60% living in low and middle-income countries. Every year, there are nearly 10 million new cases. The estimated proportion of the general population aged 60 and over with dementia at a given time is between 5-8%. The total number of people with dementia is projected to reach 82 million in 2030 and 152 in 2050. Much of this increase is attributable to the rising numbers of people with dementia living in low and middle-income countries.


Diagnosis:


There is no one test to determine if someone has dementia. Doctors diagnose Alzheimer's and other types of dementia based on a careful medical history, a physical examination, laboratory tests, and the characteristic changes in thinking, day-to-day function and behavior associated with each type. Doctors can determine that a person has dementia with a level of certainty. But it's harder to determine the exact type of dementia because of the symptoms and brain changes of different dementias can overlap. In some cases, a doctor may diagnosis dementia and not specify a type. If this occurs it may be necessary to see a specialist such as a neurologist or a psychologist.



Diagnosis requires a medical history, physical examination, including neurological examination and appropriate laboratory tests.

Taking a thorough medical history involves gathering information about the onset duration, and progression of symptoms, any possible risk factors for dementia, such as a family history of the disorder or other neurological diseases, history of stroke, and alcohol or other drug use.


The various laboratory investigations include:


- Thyroid hormone tests to check for an underactive thyroid.

- Vitamin B12 blood test to look for a vitamin deficiency.

- Complete blood count, or CBC, to look for infection.

- ALT or AST, blood tests that check liver function.

- Syphilis test to look for this disease.

- Chemistry screen to check the level of electrolytes in the blood and to check kidney function.

- Glucose test to check the level of sugar in the blood.

- MRI or CT to look for tumors.


Other lab tests that may be done include:


- HIV testing to look aids

- Erythrocyte sedimentation rate, a blood test that looks for signs of inflammation in the body.

- Toxicology screen, which examines blood, urine, or hair to look for drugs that could be causing problems.

- Antinuclear antibodies, a blood test used to diagnose autoimmune diseases

- Testing for heavy metals in the blood, such as a lead test.


Risk factors and prevention:


Although age is the strongest known risk factor for dementia, it is not an inevitable consequence of aging. Further, dementia does not exclusively affect older people- young-onset dementia accounts for up to 9% of cases. Studies show that people can reduce their risk of dementia by getting regular exercise, not smoking, avoiding harmful use of alcohol, controlling and blood sugar levels, Additional risk factors include depression, low educational attainment, social isolation, and cognitive inactivity.


Social and economic impact:


Dementia has significant social and economic implications in terms of direct medical and social care costs, and the costs of informal care. In 2015, the total global societal cost of dementia was estimated to be 818 billion, equivalent to 1.1% of global gross domestic product. The total cost as a proportion of GDP varied from 0.2% in low and middle-income countries to 1.4% in high-income countries.


Impact on families and carers:


Dementia can be overwhelming for the families of affected people and for their carers. Physical, emotional and financial pressure can cause great stress to families and carers, and support is required from the health, social and legal systems.


WHO response:


WHO recognizes dementia as a public health priority. On May 2017, the World Health Assembly endorsed the Global action plan on the public health response to dementia 2017- 2025. The plan provides a comprehensive blueprint for action, for policy-makers, international, regional and national partners, and WHO as in the following areas, addressing dementia as a public health priority, increasing awareness of dementia and establishing dementia-friendly initiatives, reducing the risk dementia, diagnosis, treatment and care, information systems for dementia, support for dementia carers, and research and innovation. An international surveillance platform, the global Dementia Observatory, has been established for policymakers and researchers to facilitate monitoring and sharing of information on dementia policies, service delivery, epidemiology, and research.


WHO has developed Towards a dementia plan, a WHO guide, which provides guidance to the Member States in creating and operationalizing a dementia plan. The guide is closely linked to WHO's GDO and includes associated tools such as a checklist to guide the preparation, development, and implementation of a dementia plan. It can be used for stakeholder mapping and priority setting.


WHO Guidelines on risk reduction of cognitive decline and dementia provide evidence-based recommendations on interventions for reducing modifiable risk factors for dementia, such as physical inactivity and unhealthy diets, as well as controlling medical conditions linked to dementia, including hypertension and diabetes. Dementia is also one of the priority conditions in the WHO mental health gap action program, which is a resource for generalists, particularly in low- and middle-income countries, to help them provide first-line care for mental, neurological and substance use disorders.