Dementia refers to the deterioration of intellectual abilities — including memory — that interferes with an individual’s ability to function in daily life. Alzheimer’s disease is the most frequent form of dementia, but other types exist.
Not everyone with memory loss has dementia. For a doctor to diagnose the condition, a sufferer must meet certain criteria, including impaired spatial and motor skills, language, judgment, attention, memory, functioning and orientation.
If you have a family member with dementia, here is what you should know about the condition.
Dementia refers not to a specific disease but to a range of symptoms that often occur in conjunction with a reduction in memory and other cognitive skills serious enough to impair daily functioning. Many people believe dementia is the same as “senility.” However, losing mental functioning is not simply an expected component of growing older.
Alzheimer’s disease makes up approximately 60 to 80 percent of dementia instances. Vascular dementia, which can result from a stroke, constitutes the second-leading cause of dementia. A variety of other causes can contribute to the condition.
For an impairment to be medically defined as dementia, two or more primary aspects of mental functioning must be negatively impacted:
- Language and communication abilities
- Judgment and reasoning
- Visual perception
- Focus and attention
Individuals with dementia may experience challenges with their short-term memory, including keeping track of personal belongings like wallets and purses. In addition, they may have problems with household tasks like preparing meals. Traveling outside their own neighborhood or getting to appointments on time also may pose obstacles in daily life.
Some types of dementia are considered to be progressive and involve symptoms that begin subtly and become worse over time. Anyone showing signs of altered thinking abilities should see a doctor as soon as possible for diagnosis and possible treatment.
The signs and symptoms of dementia can vary significantly depending on the form of the disorder. However, dementia typically involves problems with focus and attention, language and communication, memory, judgment and reasoning and visual perception.
Alzheimer’s, the most common form of dementia, causes severe challenges with thinking, memory and behavior. Symptoms usually begin slowly and worsen over time. In 2011, the guidelines for the diagnosis of Alzheimer’s were revised to reflect that the condition is a brain disease that progresses slowly and often begins long before symptoms become noticeable.
Eventually, symptoms become serious enough to interfere with or halt the ability to engage in normal daily tasks.
Trouble remembering conversations can signal the presence of Alzheimer’s or another form of dementia. In addition, difficulty recalling events, actions or names often stands as an early clinical sign of the disease. Early symptoms also include depression and apathy.
As the disease progresses, an individual may experience disorientation and confusion, trouble with speaking and walking, behavioral changes, reduced communication and poor judgment.
The most frequently cited cause of dementia is Alzheimer’s disease. In addition, strokes can cause damage to blood vessels leading to vascular dementia, the second-leading type of the disorder.
Many other conditions may cause or influence the development of dementia. Some potential causes — including vitamin deficiencies and problems with the thyroid — can be reversed with appropriate treatment.
Additional causes include brain injuries, drug toxicity, brain tumors or infections, AIDS, alcoholism, meningitis, syphilis, Pick disease, hypothyroidism and Creutzfeldt-Jakob disease.
In some instances, the underlying medical conditions that lead to dementia can be treated and some or all mental functioning lost to the disorder can be restored. In most cases, however, dementia is irreversible.
Regardless of the medical problem responsible for the development of dementia, the condition results from damage to cells in the brain. The damage causes problems with the capacity of brain cells to communicate with each other, resulting in abnormalities in behavior, thinking and feelings.
The brain includes a number of separate regions that bear responsibility for a variety of functions such as memory and motion. When cells in a specific portion of the brain become damaged, the functionality associated with that region becomes compromised.
Different forms of dementia cause damage in different areas of the brain. Alzheimer’s disease, for instance, causes elevated levels of proteins both within and outside of brain cells that compromise cell health and impair normal cellular communication. The disease often causes the earliest damage to the hippocampus, the portion of the brain responsible for memory and learning.
Diagnosis, Treatment and Care
With treatment, certain conditions that can cause dementia — including problems with the thyroid, vitamin deficiencies, depression, side effects of medication and alcohol abuse — can improve. The memory and thinking problems associated with those underlying dementia causes also may become better.
If you or a family member are experiencing changes in your thinking, memory or behavior, it’s important to seek treatment from a medical professional as quickly as possible. Many types of dementia cause symptoms that may begin slowly but become worse over time.
Evaluation by a medical professional may determine that a treatable medical condition is behind the dementia symptoms; early diagnosis can provide the opportunity to benefit from all current treatments, including participation in studies and clinical trials when appropriate.
No individual test can detect the presence of dementia. Medical professionals diagnose dementia — including Alzheimer’s disease — based on physical exams, a variety of lab tests, review of the medical history, and observation of changes in thinking and functioning associated with the different forms of dementia.
Based on symptoms and other factors, a doctor may be able to diagnose dementia but unable to diagnose a specific form of the condition. In some cases, a specialist such as a neurologist may assist in diagnosis.
Treatment depends on the specific form of dementia and its cause. Some types of dementia, such as Alzheimer’s, are progressive and cannot be cured; treatment then relies on slowing the progression or lessening symptoms.
Examples of treatment methods include:
- Vitamins for a specific deficiency.
- Surgery to remove a tumor in the brain.
- Medications to treat an infection like encephalitis.
- Thyroid therapy for hypothyroidism.
- Ceasing of medications that may contribute to confusion or disorientation.
- Medication for depression.
Risk and Prevention
Age and genetics are two significant risk factors for dementia that cannot be altered. In addition, cardiovascular function can play a significant role in the development of dementia.
Damage to blood vessels throughout the body also can damage vessels in the brain, which can rob brain cells of nourishment and oxygen. Changes in the brain’s blood vessels have a link to vascular dementia.
New research continues to uncover additional types of risk along with methods for preventing the disorder. Getting physical exercise on a regular basis may help reduce the risk of developing some forms of dementia. Research has suggested that exercise may provide direct benefit to brain cells by improving oxygen and blood flow reaching the brain.
In addition, diet may have a major impact on the health of the brain due to the relationship to heart health. Current medical guidelines promote eating in a healthy manner such as the Mediterranean diet — with minimal red meat and ample fruits, vegetables, whole grains, nuts, olive oil, fish and shellfish — to protect your brain.
Types of Dementia
Dementia occurs when the portions of the brain devoted to memory, learning, language and decision making fall prey to disease or physical damage. Treatment often can help lessen the symptoms of dementia, but many of the causes of the condition cannot be cured.
If your family member suffers from dementia, it’s important to understand the underlying causes, symptoms and potential treatments. We’ve put together a brief primer on the various types of dementia to assist you as you investigate supportive care options.
Alzheimer’s is the most common form of dementia, accounting for as many as 80 percent of cases. The disease is marked by damage and death of nerve cells in the brain, and it is considered to be a progressive disease, with symptoms worsening over several years. Alzheimer’s is the sixth-leading cause of death among Americans.
- Early symptoms include memory problems, depression and apathy
- Poor judgment, confusion, disorientation, problems with speaking, behavioral changes, and impaired communication are among later symptoms
- No cure exists. However, research continues, and treatments are available to slow the progression of symptoms and improve quality of life
CJD is a rare, fatal brain disorder that affects humans and other mammals. “Mad cow disease” is a form of CJD that occurs in cattle and occasionally has been transmitted to people.
The disorder causes prion protein — found throughout the body — to “misfold,” resulting in a domino effect of damage to the brain.
- CJD occurs in only approximately one in 1 million people globally each year
- Symptoms include rapid deterioration of coordination and memory, behavioral changes, depression, twitching and involuntary movements
- A familial variant of the disease, involving inherited genetic changes, accounts for up to 15 percent of cases
Dementia with Lewy Bodies
Lewy bodies are aberrant groups of a protein that can develop in the brain’s cortex, leading to dementia. The Lewy bodies themselves can cause dementia and also can be present during other brain changes that cause other types of dementia, such as Alzheimer’s.
- Symptoms include problems with thinking, memory loss, sleep disturbances and violently acting out dreams, gait imbalance or slowness, and visual hallucinations
- Dementia with Lewy bodies is the third-leading cause of dementia and accounts for up to one-quarter of cases
- Lewy bodies can be present in other brain disorders, including Parkinson’s disease and Alzheimer’s disease
FTD causes damage to nerve cells in the brain, resulting in loss of function. Frontotemporal deterioration can be caused by several different dementia variations, including primary progressive aphasia, corticobasal degeneration and Pick’s disease.
- Symptoms include behavioral and personality changes, as well as trouble with language
- People with FTD frequently show symptoms around age 60, which is younger than for some other types of dementia
- FTD previously was known as Pick’s disease, named for the physician who first described the condition. FTD also is referred to as frontotemporal degenerations and frontal lobe disorders
- The disease has several variants, including a behavior variant that results in prominent personality changes to judgment, empathy and other areas
Huntington’s disease is a hereditary, progressive brain disorder that often appears during middle age. Over a period of a decade or more, the disease causes nerve cells in the brain to deteriorate, impacting the mind, body and emotions.
- Early symptoms may include irritability, depression, stiffness, minor alterations to coordination and balance, uncontrolled fidgeting movements, and difficulty with thinking through situations
- Middle- and late-stage symptoms include difficulty with swallowing or speaking, falling and emotional changes. Eventually, individuals with Huntington’s disease lose the ability to walk and speak, and they become dependent on caregivers
- Excitement or stress can make symptoms worse
Mild Cognitive Impairment
MCI represents a transitional stage between normal, age-related cognitive decline and dementia. An individual with MCI may notice slight deterioration of mental functioning and memory, and family members and friends also may observe a change. However, degradation of function typically is not serious enough to interfere with daily life.
MCI may increase the risk of later development of dementia due to neurological conditions including Alzheimer’s disease.
- Frequent symptoms include forgetfulness, losing the train of thought, and feeling overwhelmed by planning or the need to make decisions
- Apathy, anxiety, irritability and depression also may occur
- Symptoms may progress, remain stable over time, or even improve
Mixed dementia occurs when an individual has brain abnormalities linked to more than one form of dementia. The condition often has characteristics of vascular dementia and Alzheimer’s but also can include conditions present in other variations, including dementia with Lewy bodies.
- Brain changes related to mixed dementia cannot be assessed in living individuals, but scientists are learning more through autopsy studies and believe the condition may be more common than previously thought.
- One study found that individuals who met the criteria for Alzheimer’s also had evidence of one or more additional types of dementia
- Symptoms can vary depending on the specific brain changes but often are similar to those of Alzheimer’s and other forms of dementia
Normal Pressure Hydrocephalus
A buildup of cerebrospinal fluid inside hollow chambers in the brain causes normal pressure hydrocephalus. In some cases, a surgeon can correct the condition by draining the excess fluid.
The condition is referred to as “normal pressure” because spinal taps often fail to show abnormal pressure despite the presence of the fluid. However, the enlarging brain chambers can damage nearby tissue, causing NPH symptoms.
- Symptoms are common in other types of brain disorders and include deteriorating thinking skills, trouble walking, and loss of control of the bladder
- The condition often affects individuals in their 60s and 70s
- Doctors often use brain imaging such as MRIs to help diagnose the condition
Parkinson’s Disease Dementia
Parkinson’s disease dementia is a type of dementia that eventually develops in individuals with Parkinson’s disease. The condition results from deep-brain changes that affect nerve cells in the brain and often presents similarly to dementia with Lewy bodies.
- As the brain changes that result from Parkinson’s disease spread, they sometimes affect mental function such as memory and judgment
- Individuals who have Parkinson’s disease dementia and dementia with Lewy bodies also may have changes characteristic of Alzheimer’s disease
- Symptoms include muffled speaking, memory and judgment changes, depression, delusions, paranoid ideas, anxiety, and sleep problems
Posterior Cortical Atrophy
Deterioration of vision is a primary result of posterior cortical atrophy, a rare, degenerative disorder of the nervous system and brain. The condition often eventually causes decreases in cognitive abilities and memory, and it may be associated with Lewy body dementia, Alzheimer’s and other brain-related conditions.
- Symptoms vary but include problems with visual tasks, including judging distance, reading, and differentiating between stationary and moving objects
- Some individuals with posterior cortical atrophy also may experience problems identifying and using common objects, along with hallucinations. Memory typically is impacted in later stages of the disease
- Misdiagnosis is common due to the varied presentation and perception of vision symptoms as physical problems with the eyes
Vascular dementia can occur as the result of strokes that block blood vessels in the brain, leading to symptoms that can begin suddenly. The restricted blood flow that results from a stroke can cause damage to cells throughout the body and especially to the network of blood vessels in the brain.
- Multiple, small strokes can result in thinking problems that begin subtly but become worse as cumulative damage mounts
- Symptoms can include disorientation, confusion, problems with understanding speech or speaking, and loss of vision.
- Memory loss may occur, depending on the specific areas of the brain affected by reduced blood flow
Korsakoff dementia is caused by a thiamine (vitamin B-1) deficiency. This type of dementia has been linked to alcohol misuse over a period of time, but has also been linked to other conditions, including AIDs.
- Symptoms include difficulty learning new information, or struggling to recall events
- In addition to alcohol misuse, Korsakoff syndrome has been linked to anorexia, fasting and weight-loss surgery
- Korsakoff syndrome can be difficult to diagnose because its symptoms often resemble those linked to head injury, withdrawal and intoxication