What Is Dementia? Symptoms, Types, and Diagnosis
Dementia is the loss or impairment of mental abilities. People often think of dementia as memory problems, but it affects many areas of cognition, including language skills, judgment, problem solving, planning, abstract thought, and social interaction. Dementia usually begins gradually, with small changes over months or even years. As the illness progresses, symptoms become more apparent.
The term “dementia” refers to a group of disorders characterized primarily by progressive decline in intellectual function. These conditions include Alzheimer’s disease, vascular dementia, Lewy body dementia, frontotemporal lobar degeneration, Parkinson’s disease dementia, corticobasal degeneration, Pick’s disease, Huntington’s disease, and Creutzfeldt–Jakob disease.
There are many types of dementias. However, Alzheimer’s disease is the most common cause of dementia among adults. Other causes include vascular dementia, Lewy Body dementia, Frontotemporal lobar dementia, Corticobasal Degeneration, Parkinson’s Disease Dementia, and Huntington’s Disease.
Alzheimer’s disease is the sixth leading cause of death in the United States. In 2013, there were 5.5 million Americans aged 65 and older who had been diagnosed with Alzheimer’s disease or related dementias. By 2050, Alzheimer’s disease is expected to rank fifth as the leading cause of death in America, according to the National Institute of Aging.
What are the signs and symptoms of dementia?
While most people lose some neurons as they age — we’re talking about 10% a decade here — those with Alzheimer’s disease experience much greater neuron loss. In fact, one study found that Alzheimer’s patients had up to 50 times more neuron death than healthy adults.
The symptoms of dementia can vary, depending upon what part of the brain is affected. For example, while many people experience problems with short-term memory, others struggle with long-term memories like names, dates, or places. Some people have trouble thinking clearly, while others become confused and disoriented. Most people with Alzheimer’s start showing symptoms around age 60, although it can begin earlier.
What causes dementia?
The causes of Alzheimer’s and other dementias are still largely unknown. Researchers have identified several different pathways that could lead to cognitive decline over time. In many cases, it appears that multiple factors contribute to the development of dementia. For example, vascular disease — such as stroke or heart attack — may damage blood vessels in the brain, causing problems with oxygen delivery to the brain cells. Other conditions, like diabetes, high cholesterol levels, obesity, depression, head injuries and smoking, may increase the risk of developing dementia. Some rare genetic mutations may cause dementia. And while there is no known way to prevent dementia, researchers believe that maintaining a healthy lifestyle may help protect against the onset of dementia.
What are the different types of dementia?
There are many different types of dementia. They affect people differently depending on what type you suffer from. Some types of dementia are more common than others. For example, Alzheimer’s disease affects nearly half of people over 85 years old. Other types include vascular dementia, Lewy body dementia, frontotemporal lobar degeneration, Parkinson’s disease dementia, Huntington’s disease dementia and prion disease dementia. There are also several rarer types of dementia such as Creutzfeldt–Jakob disease, subcortical vascular dementia and corticobasal degeneration.
How is dementia diagnosed?
To diagnose dementia, physicians first assess whether a patient has an underlying, potentially treatmentable, condition that may contribute to cognitive difficulties. They look for potential problems such as thyroid disease, diabetes, heart conditions, depression, vitamin deficiencies, sleep disorders, substance abuse, Parkinson’s disease, stroke, head trauma, brain tumors, multiple sclerosis, Alzheimer’s disease, Lewy body disease, Huntington’s chorea, Creutzfeldt–Jakob disease, progressive supranuclear palsy, corticobasal degeneration, frontotemporal lobar degeneration, normal pressure hydrocephalus, vascular dementia, and argyrophilic grain disease.
A physical examination to measure blood pressure and vital signs, including height and weight, can help identify other health issues that could affect cognition. Laboratory testing of blood and other fluids can detect abnormalities in metabolism, electrolytes, liver function, kidney function, cholesterol, triglycerides, protein levels, glucose level, and hormone levels.
Cognitive and neuropsychological tests can determine if a person has memory loss or impairment, attention deficit disorder, executive dysfunction, language deficits, visuospatial abilities, visual perception, judgment, problem solving, concentration, abstract reasoning, planning, organization, abstraction, initiative, and self-awareness. These tests can reveal early signs of dementia, even among people without significant memory complaints.
The following procedures can be used to diagnose dementia.
Cognitive and Neuropsychological Tests
Memory assessment tests evaluate different aspects of memory, including learning, recall, recognition, and ability to organize information. Memory assessments often involve reviewing lists of words, numbers, pictures, or objects over several trials. Other types of memory tests ask patients to remember specific events or sequences of events.
Who can diagnose dementia?
Visiting a primary care doctor or family physician is often the first step in diagnosing dementia. Neurologists, however, are usually consulted to diagnose dementia. Other specialists include geriatric psychiatrists, neuropsychologist, and geriatricians. Medical schools offer training programs in dementia diagnosis and management.
If a specialist cannot be found within your local area, contact the nearest medical college neurology department for a recommendation. A university hospital may have a dementia clinic where experts evaluate patients.
Rates of dementia
The worldwide prevalence of dementia is set to increase dramatically in coming decades. A report published today by Alzheimer’s Disease International estimates that there are now about 55 million people with dementia globally, with numbers rising to 65 million by 2030 and 75 million by 2050. This represents a significant shift from current trends, where rates of dementia are falling in high-income countries, while remaining stable or even declining in many developing regions. In addition to being a major public health challenge, dementia places enormous economic burdens on individuals, families and society. For example, it costs governments in developed economies $818 billion per year, equivalent to 3% of GDP.
Treatment and care
There is currently no treatment available for dementia. However, anti-dementia medicines, including cholinesterase inhibitors, are approved for use in mild to moderate Alzheimer’s disease and some forms of vascular dementia. Disease-modifying therapies are still under development. In addition, there are many promising novel approaches in preclinical studies, such as immunotherapies, gene therapy, stem cell transplantation, neuroprotective agents and others.
The principal goals for dementia care include:
early diagnosis in order to promote earlier initiation of appropriate interventions;
optimizing physical health, cognition, activities and wellbeing;
supporting family carers and improving quality of life for those affected by dementia.
Risk factors and prevention
Aging is the greatest risk factor for dementia, accounting for 80% of cases. However, there are many modifiable risk factors that can prevent or delay dementia. These include physical activity, nutrition, sleep, mental health, vascular disease, head injury and stroke. Some of these risk factors are easier to control than others. For example, you cannot do much about genetics, but you can make changes to your lifestyle.
Although age is the strongest known predictor of developing dementia, it is not the only one. Other risk factors include depression, low education level, lack of exercise, obesity, poor diet, high blood pressure, diabetes, heart disease, stroke and head injuries. A study published in 2018 found that almost half of people over 85 had evidence of brain shrinkage, even though they did not have dementia. This suggests that some people are born with smaller brains and therefore have a greater chance of developing dementia later in life.
Social and economic impact
The World Alzheimer Report 2019 estimates that there are 50 million informal caregivers worldwide – most commonly family members and close friends – whose lives are affected by caring for someone with dementia. Of those, one in three live in developing countries. Informal caregiving is associated with high levels of physical, mental and financial burden.
Informal caregivers spend on average five hours a day providing care for people with dementia. They often feel overwhelmed and stressed out. This can lead to depression and anxiety, and it can take a toll on their personal relationships and finances.
Fifty percent of the global cost for dementia is attributed to informal caregiver costs. These include lost productivity, medical expenses, housing and transportation costs.
Dementia vs. Other Types of Memory Loss
There are several types of memory loss, including dementia, Alzheimer’s disease, amnesia, and normal aging. People often confuse dementia with temporary confusion or forgetfulness caused by an infection that heals without proper medical attention. There are many different causes of dementia, including an underlying illness or side effect of medication. Dementia usually gets worse over time. Symptoms include problems with thinking, judgment, language, behavior, and mood.