Dementia

Alzheimer's dementia

A drawing of a woman diagnosed with dementia.

A drawing of an old man diagnosed with senile dementia

Brain atrophy in severe Alzheimer's

Donepezil

Old woman from Ethiopia

Dementia is a broad category of brain diseases that cause a long-term and often gradual decrease in the ability to think and remember, which is severe enough to affect daily functioning. Other common symptoms include emotional problems, difficulties with language, and a decrease in motivation. Consciousness is usually not affected. A diagnosis of dementia requires a change from a person's usual mental functioning and a greater decline than one would expect due to aging. These diseases have a significant effect on caregivers.

Types of Dementia

The most common type of dementia is Alzheimer's disease, which makes up 50% to 70% of cases. Other common types include:

• Vascular dementia (25%)
• Dementia with Lewy bodies (15%)
• Frontotemporal dementia

Less common causes include:

• Normal pressure hydrocephalus
• Parkinson's disease dementia
• Syphilis
• HIV
• Creutzfeldt–Jakob disease

More than one type of dementia may exist in the same person. A small proportion of cases run in families. In the DSM-5, dementia was reclassified as a neurocognitive disorder, with degrees of severity.

Diagnosis and Screening

Diagnosis is usually based on history of the illness and cognitive testing, with medical imaging and blood tests used to rule out other possible causes. The Mini Mental State Examination (MMSE) is one commonly used cognitive test. Efforts to prevent dementia include trying to decrease risk factors such as high blood pressure, smoking, diabetes, and obesity. Screening the general population for the disorder is not recommended.

Treatment and Management

There is no known cure for dementia. Cholinesterase inhibitors such as donepezil are often used and may be beneficial in mild to moderate disorder. 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. Educating and providing emotional support to the caregiver is important. Exercise programs may be beneficial with respect to activities of daily living and potentially improve outcomes. Treatment of behavioral problems with antipsychotics is common but not usually recommended, due to the limited benefit and the side effects, including an increased risk of death.

Global Impact

Globally, dementia affected about 46 million people in 2015. About 10% of people develop the disorder at some point in their lives. It becomes more common with age. About 3% of people between the ages of 65–74 have dementia, 19% between 75 and 84, and nearly half of those over 85 years of age. In 2013 dementia resulted in about 1.7 million deaths, up from 0.8 million in 1990. As more people are living longer, dementia is becoming more common. For people of a specific age, however, it may be becoming less frequent, at least in the developed world, due to a decrease in risk factors. It is one of the most common causes of disability among the elderly. It is believed to result in economic costs of US$604 billion a year. People with dementia are often physically or chemically restrained to a greater degree than necessary, raising issues of human rights. Social stigma against those affected is common.

Signs and Symptoms

The symptoms of dementia vary across types and stages of the diagnosis. The most commonly affected areas include memory, visual-spatial, language, attention, and problem solving. Most types of dementia are slow and progressive. By the time signs of the disorder are apparent, deterioration in the brain has already been occurring for a long time. The course of dementia varies depending on the type, but generally progresses through three stages: mild (early-stage), moderate (middle-stage), and severe (late-stage).

Mild (Early-Stage)

In the early stage of dementia, the person may:

• Experience forgetfulness, particularly of recent events
• Have difficulty managing finances
• Struggle with planning and organizing
• Become disoriented, especially in unfamiliar environments
• Show subtle changes in personality or behavior

Moderate (Middle-Stage)

As dementia progresses to the moderate stage, the person may:

• Require assistance with activities of daily living (ADLs), such as dressing, grooming, and eating
• Exhibit increased memory loss and confusion
• Struggle with recognizing familiar faces and places
• Experience mood and behavioral changes, such as agitation, depression, or paranoia
• Display sleep disturbances, including insomnia or night wandering

Severe (Late-Stage)

In the severe stage of dementia, the person may:

• Lose the ability to communicate coherently or at all
• Require full-time assistance with ADLs
• Exhibit severe physical decline, including difficulty walking, sitting, and swallowing
• Experience incontinence
• Become more susceptible to infections, particularly pneumonia

Risk Factors and Prevention

Several risk factors are associated with dementia, including age, family history, genetics, and lifestyle factors. Some of these factors, such as age and genetics, are non-modifiable. However, there are modifiable risk factors that can be addressed to reduce the risk of developing dementia:

• Maintain a healthy diet, such as the Mediterranean diet
• Engage in regular physical activity
• Manage chronic health conditions, such as diabetes, hypertension, and high cholesterol
• Maintain a healthy weight
• Avoid smoking and limit alcohol consumption
• Stay mentally and socially active

Research and Future Directions

Research on dementia is ongoing, with scientists striving to better understand the causes, develop effective treatments, and ultimately find a cure. Current research areas include:

• Investigating the role of genetics in the development and progression of dementia
• Studying the effectiveness of various drug therapies
• Developing new diagnostic tools and techniques for early detection
• Exploring the potential benefits of non-pharmacological interventions, such as cognitive stimulation therapy and physical exercise
• Investigating the potential of stem cell therapy and other novel treatments
• As our understanding of dementia improves, it is hoped that new therapies and preventive strategies will be developed to help reduce the global burden of this debilitating condition.

External links

Classification	ICD-10: F00 , F01 , F02 , F03 MeSH: D003704 DiseasesDB: 29283
External resources	MedlinePlus: 000739 eMedicine: article/793247

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