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About Dementia
Dementia: Dementia is a general term that describes a group of symptoms related to the loss of multiple intellectual functions—such as loss of memory, judgment, language and complex motor skills—that interferes with daily living.
Fact: Dementia is a common disorder in people aged 65 and older (10 percent), and very common in those 85+ (47 percent).
Causes of Dementia
Dozens of diseases or conditions can cause dementia. Some of these dementias are reversible; others are irreversible.
Alzheimer's disease is the most common cause of dementia in persons older than 65. It is irreversible and represents about 60 percent of all dementias. After Alzheimer’s disease, vascular dementia and Lewy body dementia are the most common.
Each type of dementia is characterized by different structural changes in the brain, such as an accumulation of abnormal plaques and tangles in individuals with Alzheimer's disease, and abnormal tau protein in individuals with frontotemporal dementia.
The clinical symptoms and the progression of dementia vary, depending on the type of disease causing it, and the location and number of damaged brain cells. Some types progress slowly over years, while others may result in sudden loss of intellectual function.
These neurodegenerative diseases—diseases that involve the
progressive death or dysfunction of brain cells—can cause dementia:
- Alzheimer’s disease
- Vascular dementia
- Lewy body dementia
- Mixed dementia (Alzheimer’s disease and vascular dementia)
- Parkinson’s disease with dementia
- Frontotemporal dementia
- Huntington’s disease
- Creutzfeldt-Jakob disease
- Niemann-Pick’s disease
- Multi-infarct dementia
Other types of dementia are caused by:
- Alcohol
- Brain injury/trauma
- Brain inflammation
- AIDS
Some causes of dementia that can be treated or reversed are:
- Vitamin deficiency
- Thyroid problems
- Depression
- Medication side effects
- Normal-pressure hydrocephalus
- Metabolic disorders (liver, kidneys, pancreas)
- Hormone imbalance
- Infections
Dementia is more common later in life, but it is not a normal part of aging.
Warning Signs of Dementia
The warning signs of dementia vary depending on the type of disease causing it. If someone is exhibiting these symptoms, the person should check out his or her concerns with a healthcare professional. Awareness of these warning signs is not a substitute for a structured screening or consultation with a primary care provider.
- Trouble with new memories
- Relying on memory helpers
- Trouble finding words
- Struggling to complete familiar actions
- Confusion about time, place or people
- Misplacing familiar objects
- Onset of new depression or irritability
- Making bad decisions
- Personality changes
- Loss of interest in important responsibilities
- Seeing or hearing things
- Expressing false beliefs
Diagnosis of Dementia
Experienced clinicians can accurately diagnose most common types of dementia 90 percent of the time. Mixed dementia—Alzheimer’s disease and vascular dementia together—is more difficult to diagnose.
Accurate diagnosis is critical. Some conditions that cause symptoms of dementia, such as hormone imbalance, vitamin deficiency and infections, can be reversed. For irreversible dementias, treatment options vary depending on the disease.
Obtaining a proper diagnosis involves consulting with a healthcare provider knowledgable about dementia, communicating symptoms and undergoing extensive testing.
Diagnostic tools include:
- Complete medical history
- Psychiatric history, including substance abuse and depression
- Family history
- Review of medications
- Blood, urine or other medical tests
- Neuropsychological tests, including memory screenings, that measure memory, problem solving, attention, and language
- Brain scans
Individuals with clinically diagnosed dementia have clear cognitive loss in two or more intellectual domains, such as amnesia, or loss of memory, and aphasia, or the inability to communicate effectively. Almost all individuals with Alzheimer's disease demonstrate short-term memory impairment as one of the symptoms.
Treatment options and pharmacological non-interventions vary depending on the type of dementia.
Symptoms of Dementia
Dementia involves the loss of two or more brain functions that interfere with daily living. Memory loss is a common symptom.
The clinical symptoms of dementia vary from person to person. They also depend on the type of disease causing dementia and the location and number of damaged brain cells. With Alzheimer's disease, signs of all symptoms are quite probable; with other types of dementia, it is possible to have some or all of the symptoms. Some dementias progressively worsen over time; others do not.
Symptoms are divided into cognitive symptoms, or intellectual symptoms, psychiatric symptoms and functional symptoms.
Differentiating between cognitive symptoms and psychiatric symptoms is important so that behavioral problems that are caused by loss of cognitive functioning are not treated with antipsychotic or antianxiety medications.
Cognitive Symptoms of Dementia
Cognitive, or intellectual, symptoms are:
- Amnesia—loss of memory or the inability to remember facts or events. We have two types of memories: short-term (recent, new) and long-term (remote, old) memories. Short-term memory is programmed in a part of the brain called the temporal lobe, while long-term memory is stored throughout extensive nerve cell networks in the temporal and parietal lobes. In Alzheimer's disease, short-term memory storage is damaged first.
- Aphasia—the inability to communicate effectively. The loss of ability to speak and write is called expressive aphasia. An individual may forget words and have increasing difficulty with communication. With receptive aphasia, an individual may be unable to understand spoken or written words or may read and not understand a word of what is read. Sometimes an individual pretends to understand and even nods in agreement; this is to cover up aphasia. Although individuals may not understand words and grammar, they may still understand non-verbal behavior, such as smiling.
- Apraxia—the inability to do pre-programmed motor tasks or to perform activities of daily living such as brushing teeth and dressing. An individual may forget all motor skills learned during development. Sophisticated motor skills that require extensive learning, such as job-related skills, are the first functions that become impaired. More instinctive functions like chewing, swallowing and walking are lost in the last stages of the disease.
- Agnosia—the inability to correctly interpret signals from a perrson’s five senses. Individuals with Alzheimer's disease may not recognize familiar people and objects. A common yet often unrecognized agnosia is the inability to appropriately perceive internal information such as a full bladder or chest pain.
Psychiatric Symptoms of Dementia
In addition to cognitive symptoms that develop in individuals with dementia, psychiatric symptoms are common.
Differentiating between cognitive symptoms and psychiatric symptoms is important so that behavioral problems that are caused by loss of cognitive functioning are not treated with antipsychotic or antianxiety medications.
Major psychiatric symptoms of dementia may include:
- Personality changes—These changes can become evident in the early stages of dementia. Signs include irritability, apathy, withdrawal and isolation.
- Depression—Individuals with dementia may show symptoms of depression at any stage of the disease. Depression is treatable, even in the later stages of dementia.
- Hallucinations— Hallucinations occur in about 25 percent of cases, usually in the middle stage of dementia. They are typically auditory and/or visual. Sensory impairments, such as hearing loss or poor eyesight, tend to increase hallucinations in the elderly with dementia.
- Delusions—Delusions affect about 40 percent of individuals with dementia and usually occur in the middle stage of dementia.
- Delirium—This is a temporary confusion caused by underlying medical problems, drug toxicity or environmental factors. It is a very common, yet often unrecognized condition in elderly individuals with dementia. Signs include confusion and disorientation; fluctuating levels of consciousness; jerking motions; disruption of sleep-wake cycles; hallucinations, delusions and anxiety; memory impairment; mood changes; and behavioral changes such as agitation, aggression and wandering.
Treatment may include carefully-supervised use of medications and behavioral interventions. Use of antipsychotic drugs for dementia has been controversial, and the U.S. Food and Drug Administration in recent years has required drug labels to carry so-called “black box” warnings regarding them. Current research shows that antipsychotic drugs are associated with increased mortality rates in individuals with dementia.
Functional Symptoms of Dementia
Functional impairments include inability to perform common activities of daily living (ADLs)—the basic tasks involved in every day life.
Activities of daily living include:
- Bathing
- Dressing
- Toileting
- Eating
- Personal hygiene (grooming, oral care)
- Transferring