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Jai Ganesh

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Dementia

Dementia

Gist

Dementia is the loss of cognitive functioning — thinking, remembering, and reasoning — to such an extent that it interferes with a person's daily life and activities. Some people with dementia cannot control their emotions, and their personalities may change.

Summary

Dementia, chronic, is usually progressive deterioration of intellectual capacity associated with the widespread loss of nerve cells and the shrinkage of brain tissue. Dementia is most commonly seen in the elderly (senile dementia), though it is not part of the normal aging process and can affect persons of any age. In 2005 researchers reported that some 24.3 million people worldwide were living with dementia. In 2015 this figure rose to an estimated 47.5 million, a number that was expected to increase significantly by 2030, in part because of anticipated increases in life expectancy in many countries.

The most common irreversible dementia is Alzheimer disease. This condition often begins with memory loss or with subtle impairments in other cognitive functions. These changes may manifest initially as simple absentmindedness or forgetfulness or as minor problems with judgment, language, or perception. As dementia progresses, memory loss and cognitive impairment broaden in scope until the individual can no longer remember basic social and survival skills or function independently. Language, spatial or temporal orientation, judgment, perception, and other cognitive capacities decline, and personality changes may occur. Dementia is also present in other degenerative brain diseases, including Pick disease and Parkinson disease. Alzheimer disease closely resembles another form of dementia known as limbic-predominant age-related TDP-43 encephalopathy (LATE). Although LATE is also marked by the deterioration of memory and cognition and declines in social skills, patterns of neurocognitive change and the rate of decline in LATE differ from Alzheimer disease.

The second most common cause of dementia is hypertension (high blood pressure) or other vascular conditions. This type of dementia, called multi-infarct, or vascular, dementia results from a series of small strokes that progressively destroy the brain. Dementia can also be caused by Huntington disease, syphilis, multiple sclerosis, acquired immune deficiency syndrome (AIDS), and some types of encephalitis. Treatable dementias occur in hypothyroidism, other metabolic diseases, and some malignant tumours. Treatment of the underlying disease in these cases may inhibit the progress of dementia but usually does not reverse it.

Because many instances of dementia are not necessarily a consequence of aging but rather are associated with lifestyle factors, certain behaviour actions can help delay or potentially prevent dementia. Guidelines for dementia prevention issued by the World Health Organization include engaging in physical activity, never smoking, limiting alcohol intake, eating a healthy diet, and managing weight. Particularly in persons age 55 or older, risk of dementia may be increased by the use of certain prescription drugs, especially anticholinergic agents, which are used to treat a variety of conditions, including allergies, bladder disorders, chronic obstructive pulmonary disease (COPD), and depression.

Details

Dementia is a disorder which manifests as a set of related symptoms, which usually surfaces when the brain is damaged by injury or disease. The symptoms involve progressive impairments in memory, thinking, and behavior, which negatively affects a person's ability to function and carry out everyday activities. Aside from memory impairment and a disruption in thought patterns, the most common symptoms include emotional problems, difficulties with language, and decreased motivation. The symptoms may be described as occurring in a continuum over several stages. Consciousness is not affected. Dementia ultimately has a significant effect on the individual, caregivers, and on social relationships in general. A diagnosis of dementia requires the observation of a change from a person's usual mental functioning and a greater cognitive decline than what is caused by normal aging.

Several diseases and injuries to the brain such as a stroke can give rise to dementia. However, the most common cause is Alzheimer's disease, a neurodegenerative disorder. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), has re-described dementia as either a mild or major neurocognitive disorder with varying degrees of severity and many causative subtypes. The International Classification of Diseases (ICD-11) also classes dementia as a neurocognitive disorder (NCD) with many forms or subclasses. Dementia is listed as an acquired brain syndrome, marked by a decline in cognitive function, and is contrasted with neurodevelopmental disorders.[14] Dementia is also described as a spectrum of disorders with causative subtypes of dementia based on a known disorder, such as Parkinson's disease, for Parkinson's disease dementia; Huntington's disease, for Huntington's disease dementia; vascular disease, for vascular dementia; HIV infection, causing HIV dementia; frontotemporal lobar degeneration for frontotemporal dementia; or Lewy body disease for dementia with Lewy bodies, and prion diseases. Subtypes of neurodegenerative dementias may also be based on the underlying pathology of misfolded proteins such as synucleinopathies, and tauopathies. More than one type of dementia existing together is known as mixed dementia.

Many neurocognitive disorders may be caused by another medical condition or disorder that includes brain tumours, and subdural hematoma; endocrine disorders such as hypothyroidism, and hypoglycemia; nutritional deficiencies including thiamine, and niacin; infections, immune disorders, liver or kidney failure, metabolic disorders such as Kufs disease, and some leukodystrophies, and neurological disorders such as epilepsy, and multiple sclerosis. Some of the neurocognitive deficits may sometimes show improvement with treatment of the medical condition.

Diagnosis is usually based on history of the illness and cognitive testing with imaging. Blood tests may be taken to rule out other possible causes that may be reversible, such as hypothyroidism (an underactive thyroid), and to determine the dementia subtype. One commonly used cognitive test is the Mini-Mental State Examination. The greatest risk factor for developing dementia is aging, however dementia is not a normal part of aging. Many people aged 90 and above show no signs of dementia. Several risk factors for dementia, such as smoking and obesity, are preventable by lifestyle changes. Screening the general older population for the disorder is not seen to affect the outcome.

Dementia is currently the seventh leading cause of death worldwide and has 10 million new cases reported every year (one every ~3 seconds). There is no known cure for dementia. Acetylcholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disorder. The overall benefit, however, may be minor. There are many measures that can improve the quality of life of people with dementia and their caregivers. Cognitive and behavioral interventions may be appropriate for treating associated symptoms of depression.

Signs and symptoms

The signs and symptoms of dementia are termed as the neuropsychiatric symptoms, also known as the behavioral and psychological symptoms of dementia. Behavioral symptoms can include agitation, restlessness, inappropriate behavior, sexual disinhibition, and aggression, which can be verbal or physical. These symptoms may result from impairments in cognitive inhibition. Psychological symptoms can include depression, hallucinations (most often visual), and delusions, apathy, and anxiety. The most commonly affected areas include memory, visuospatial function affecting perception and orientation, language, attention and problem solving. The rate at which symptoms progress occurs on a continuum over several stages, and they vary across the dementia subtypes. Most types of dementia are slowly progressive with some deterioration of the brain well established before signs of the disorder become apparent. Often there are other conditions present such as high blood pressure, or diabetes, and there can sometimes be as many as four of these comorbidities.

People with dementia are also more likely to have problems with incontinence: they are three times more likely to have urinary and four times more likely to have fecal incontinence compared to people of similar ages.

Dementia symptoms can vary widely from person to person. It affects memory, attention span, communication, reasoning, judgement, problem solving and visual perception, etc. Signs that may point to dementia include getting lost in a familiar neighborhood, using unusual words to refer to familiar objects, forgetting the name of a close family member or friend, forgetting old memories, not being able to complete tasks independently, etc.

Additional Information

Dementia is a broad term that describes a loss of thinking ability, memory, attention, logical reasoning, and other mental abilities. These changes are severe enough to interfere with social or occupational functioning.

Many things can cause dementia. It happens when the parts of your brain used for learning, memory, decision making, and language are damaged or diseased.

You might also hear it called major neurocognitive disorder. Dementia isn’t a disease. Instead, it's a group of symptoms caused by other conditions.

About 5%-8% of adults over age 65 have some form of dementia. This percentage doubles every 5 years after 65. As many as half of people in their 80s have some dementia.

Alzheimer's disease is the most common cause of dementia. Between 60%-80% of people with dementia have Alzheimer's. But there are as many as 50 other causes of dementia.

Dementia symptoms may improve with treatment. But many of the diseases that cause dementia aren't curable.

Types of Dementia

These forms of dementia are partially manageable, but they aren't reversible:

* Alzheimer's disease
* Vascular dementia
* Dementia from Parkinson's disease and similar disorders
* Dementia with Lewy bodies
* Frontotemporal dementia (Pick's disease)
* Creutzfeldt-Jakob disease

Dementia can be split into two groups based on which part of the brain is affected.

Cortical dementias happen because of problems in the cerebral cortex, the outer layer of the brain. They play a critical role in memory and language. People with these types of dementia usually have severe memory loss and can't remember words or understand language. Alzheimer's and Creutzfeldt-Jakob disease are two forms of cortical dementia.

Subcortical dementias happen because of problems in the parts of the brain beneath the cortex. People with subcortical dementias tend to show changes in their speed of thinking and ability to start activities. Usually, people with subcortical dementia don't have forgetfulness and language problems. Parkinson's disease, Huntington's disease, and HIV can cause these types of dementia.

Some types of dementia affect both parts of the brain. For example, Lewy Body dementia is both cortical and subcortical.

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