Dementia is a decline in mental function that may interfere with the ability to perform daily tasks. Dementia is a common condition, especially among older people. However, dementia should not be considered a normal part of aging.
There are many different types and causes of dementia. According to the National Institutes of Health, Alzheimer’s disease is the most common cause of dementia, followed by vascular dementia. Vascular dementia is caused by a lack of blood to the brain, often following a stroke. Other types of dementia include:
- Lewy body dementia
- Frontotemporal dementia
- Corticobasal degeneration
- Huntington’s disease
- Creutzfeldt-Jakob disease (CJD)
The biggest risk factor for dementia is age. People over the age of 85 are more likely to experience the condition, although some forms of dementia occur in people under the age of 50. Some individuals are genetically more susceptible to develop certain forms of dementia, such as Alzheimer’s and Huntington’s diseases. Additionally, several factors can cause temporary or permanent dementia, such as:
- Brain injuries (including damage caused by stroke)
- Reaction to medication
- Brain tumor or lesion
Memory loss is one of the most characteristic symptoms of dementia, along with language difficulties, poor judgment and personality changes. People who begin to display signs and symptoms of dementia may be referred to a physician who will likely conduct tests to assess the cause and extent of dementia. Some causes of dementia are often treatable and reversible (e.g., dementia due to malnutrition). However, sometimes dementia reflects permanent damage to the brain, or can grow progressively worse over time.
Dementia can affect many aspects of the patient’s life. As the disease progresses, the patient may not be able to drive or live independently. This can be frustrating for both the patient and caregivers. In some cases, professional round-the-clock assistance is required to care for the patient.
Dementia is a decline in mental function that may interfere with the ability to perform daily activities. Dementia is not a disease. Instead it describes a collection of symptoms (most commonly memory loss, behavioral changes and problems with language) that generally occur together and can be caused by certain conditions. There are almost 7 million people with dementia in the United States, according to the National Institute of Neurological Disorders and Stroke (NINDS).
Dementia is classified in many different ways. Some physicians and scientists classify dementia as being either cortical or subcortical. Cortical dementia occurs as a result of impairment or damage to the cerebral cortex. This is the outer layer of the brain and is associated with memory and language, along with many other aspects of consciousness. Cortical dementias (e.g., Alzheimer’s disease, Creutzfeldt-Jakob disease) often result in loss of memory and language skills.
Subcortical dementia results from impairment or damage to parts of the brain underneath the cerebral cortex. Because the cortex can be undamaged, people with subcortical dementia (such as those with Huntington’s disease) rarely experience memory loss and problems with language. Instead, people with subcortical dementia can experience behavior and personality changes, resulting in socially inappropriate and unusual actions.
Some forms of dementia are progressive, which means that they get worse over time. Alzheimer’s disease, Lewy body dementia and frontotemporal dementia are all forms of progressive dementia. Most progressive forms of dementia are poorly understood by physicians and scientists and can be difficult or impossible to treat. Other forms of dementia, especially those caused by factors such as medical reactions, alcohol abuse and malnutrition, are usually temporary and reversible.
Types and differences of dementia
The most common type of dementia is Alzheimer’s disease, which is thought to affect 4.5 million people in the United States, according to the National Institutes of Health. Alzheimer’s disease is a progressive, degenerative neurological disorder that occurs when neurons in the brain die or break their connections with other neurons. This is believed to occur because of abnormal lesions in the brains of people with Alzheimer’s disease called beta-amyloid plaques and neurofibrillary tangles. These plaques and tangles disrupt brain function and are known to increase in quantity as Alzheimer’s disease progresses.
Another common form of dementia is vascular dementia, which accounts for up to 20 percent of all dementias according to National Institute of Neurological Disorders and Stroke (NINDS). Vascular dementia is caused by lack of blood flow to the brain, usually following a stroke. It is the second most common type of dementia in older people. Unlike Alzheimer’s disease, vascular dementia often develops suddenly after a cerebrovascular event and may or may not get worse over time. Some patients may recover certain aspects of cognitive function after a period of time.
There are different types of vascular dementias. Multi-infarct dementia (MID), for example, is caused by multiple small strokes in the brain. People with MID can experience only isolated symptoms of dementia such as memory loss or language impairments, depending on the area of the brain damaged by the strokes. A rare type of vascular dementia, Binswanger’s disease, is caused by damage to the small blood vessels in the brain. People with Binswanger’s disease often experience other symptoms such as urinary incontinence, clumsiness and problems walking.
Other types of dementia include:
- Lewy body dementia. This progressive dementia is similar to Alzheimer’s disease in that its symptoms seem to be caused by the build up of pieces of protein (Lewy bodies) within the neurons of the brain. People with Lewy body dementia also experience pronounced lapses in concentration or alertness, visual hallucinations and Parkinson’s disease-like motor function problems. People with Lewy body dementia often have clinical signs of Parkinson’s disease and Alzheimer’s disease. However, the true relationship between Lewy body dementia, Alzheimer’s disease and Parkinson’s disease is not yet fully understood.
- Frontotemporal dementia. Also called frontal lobe dementia, frontotemporal dementia results from damage to the frontal and/or temporal lobes of the brain. People with frontotemporal dementia develop changes in a protein known as tau. Frontotemporal dementia is a type of dementia that results in mood and personality changes, which means that some people with frontotemporal dementia may exhibit inappropriate behavior (e.g. stealing, cursing) and have problems in social situations.
- Corticobasal degeneration. This progressive dementia is more common in people over age 60 and is the result of nerve cell loss throughout the brain. People with corticobasal degeneration experience symptoms that are similar to Parkinson’s disease along with the conventional symptoms of dementia, including, most notably, apraxia (the inability to make purposeful movements).
- Huntington’s disease. This type of dementia is hereditary and is caused by a genetic abnormality. Children whose parents have Huntington’s disease have a 50 percent chance of developing the disorder, according to NINDS. Unlike many forms of dementia, the symptoms of Huntington’s disease, which include personality changes, psychosis and abnormal muscle movements, begin to develop in the patient’s 30s or 40s. After diagnosis, people with Huntington’s disease live for about an average of approximately 15 years.
- Creutzfeldt-Jakob disease (CJD). Although CJD has received a large amount of media coverage over the last few years, the disease is still very rare. CJD is a type of progressive dementia caused by a prion, which is an infectious protein. Individual can be infected with the prion by consuming the brain or spinal tissue of an animal that has been infected. In animals, a variant of CJD is calledh mad cow disease. In can also be hereditary. People with CJD may experience personality changes, hallucinations, blindness and problems with coordination.
- Niemann Pick disease.Dementia may occur as a symptom of this group of genetic disorders. Patients with the disease cannot metabolize cholesterol and other types of fats normally, and these fats accumulate in the brain. The disease may begin during childhood, adolescence or early adulthood.
Risk factors and causes of dementia
One of the biggest risk factors for most types of dementia is age. Although some forms of dementia may affect those under 50 – some even occur in children – the risk of dementia occurrence increases rapidly as people age. For example, the number of people with Alzheimer’s disease doubles every five years after the age of 65, according to the National Institute of Neurological Disorders and Stroke (NINDS). However, it is important to note that dementia is not part of the normal aging process. Some people have a long lifespan and experience only a very slight mental decline.
Another important risk factor for many forms of dementia is genetics and family history. Some forms of dementia can be traced to genetic abnormalities. This is the case with Huntington’s disease, which is passed from parent to child through a gene mutation. Additionally, people who have a sibling or parent with Alzheimer’s disease are more likely to develop the disease themselves. This risk is even greater if more than one member of the family has been diagnosed with Alzheimer’s disease. The specific relationship between genetics and dementia is still being studied.
Some causes of dementia include:
- Stroke. A stroke is a life-threatening event in which part of the brain is deprived of adequate oxygen (hypoxia). Also known as a cerebrovascular accident (CVA) or a “brain attack,” a stroke occurs when a blood vessel in the brain bursts or becomes clogged by a blood clot or other mass. This prevents oxygen and nutrients from traveling to nerve cells in the affected area of the brain. These nerve cells can die within minutes, and the area of the body they control can cease to function. In many cases, this damage is permanent, especially if the patient is not treated immediately. Stroke is the most common cause of vascular dementia.
- Brain injury. Dementia may occur following a traumatic head injury, depending on which part of the brain is affected. Repeated concussions (such as those sustained while boxing) increase the risk for dementia pugilistica, a form of dementia that can also result in Parkinson-like symptoms.
- Malnutrition or metabolic disorders. Malnutrition is defined as the deficiency in one or more vital nutrients. Many people are malnourished without realizing it, especially if they do not eat a balanced diet. Deficiency in any of the B vitamins may result in dementia. Some people are unable to absorb or metabolize certain vitamins or minerals, which may lead to dementia. In some cases, treatment for malnutrition or metabolic disorders may reverse the dementia.
- Infections. Some infections, especially those that cause high fever, can cause many of the symptoms of dementia. These are often resolved once the infection has been treated. Infections that directly affect the brain, such as human immunodeficiency virus (HIV) and meningitis, can result in more severe and possibly permanent brain damage and dementia. An untreated infection with the sexually transmitted disease syphilis can lead to tertiary syphilis, which can include symptoms of dementia.
- Medication reactions. Some medications can cause memory loss and other symptoms of dementia as a side effect. These may include medications used to treat depression, seizures or Parkinson’s disease. Additionally, some medications interact with other substances to produce symptoms similar to dementia. People who experience symptoms of dementia should inform their physician of all medications they are taking. They should also consult with their physician about any vitamin supplements, topical treatments or over-the-counter products they are taking.
- Drug and alcohol use. Abusing most illegal drugs may lead to symptoms of dementia, which can normally be resolved once the substances are removed from the body. Severe alcohol abuse, especially heavy drinking followed by sudden withdrawal, can lead to a permanent form of dementia called Wernicke-Korsakoff disorder.
- Poisoning. Some substances such as lead and mercury can cause dementia if people are exposed to unsafe levels. Mercury poisoning is generally associated with broken thermometers or working in a thermometer factory. Lead poisoning is more common and can occur after exposure to lead-based paint used in older homes, breathing contaminated air or eating contaminated food.
- Brain tumor or lesion. Tumors or brain lesions, which can cause pressure to build up in the brain, can disrupt the function of neurons. This can lead to symptoms of dementia. In certain cases, removal of the tumor or lesion can restore cognitive function, although sometimes the damage may be permanent.
Signs and symptoms of dementia
The most commonly recognized symptom of dementia is memory loss. People with dementia, especially a cortical dementia such as Alzheimer’s disease, often have problems transferring short-term memory into long-term memories. This may include forgetting the name of someone who has just been introduced or asking the same question repeatedly without ever remembering what the answer was or even asking the question in the first place. People with dementia may also find themselves misplacing items or putting them in strange places (e.g. the phone in the freezer, keys in the oven). In most cases memory loss gets worse over time and is one of the most debilitating symptoms of dementia.
Other symptoms of dementia may include:
- Aphasia. Aphasia is a loss of the ability to use and understand language. People with dementia may forget words and have difficulty communicating with others (expressive aphasia). They may also have problems understanding spoken or written words (receptive aphasia). It is often described as being similar to traveling to a foreign country and being surrounded by people speaking an unknown language.
- Poor judgment. People with dementia may exercise poor judgment when it comes to making decisions. For example, they may not wear a coat when it is obviously cold outside.
- Mood and personality changes. People with dementia, particularly subcortical dementia (e.g. Huntington’s disease), may find that they experience sudden changes of mood or personality. This can be especially hard for caregivers to cope with.
- Lethargy and depression. Many people with dementia experience some form of depression, often because of chemical imbalances in the brain. The frustration associated with dementia can also cause depression and lethargy and patients may stop attempting to communicate or perform certain tasks.
Diagnosis methods for dementia
People who are concerned about a decline in cognitive function, including memory loss or unusual changes in mood or behavior should consult their physician as soon as possible. Diagnosis will usually begin with a medical history and a physical examination. People are encouraged to keep a log of their symptoms to report to their physician. A physician may also ask family members or close friends about the nature of the patient’s symptoms. During the medical history, the physician may ask questions related to the patient’s dietary habits and use of alcohol in order to establish potential causes of dementia that can be reversible. During the physical examination, the physician will likely assess neurological function by testing the patient’s reflexes, balance and coordination.
A physician may conduct a mental status examination to assess the patient’s stage of dementia. During the exam, the physician may ask the patient a variety of questions aimed at testing the patient’s awareness of surroundings, problem solving skills and memory skills. Examples of items on the test may include:
- Situational questions such as “What year is it?” or “What is the address of this office?”
- Remembering and recalling a short list of items (e.g. a ball, a pencil, a dog)
- Counting backwards or spelling a word backwards
- Naming familiar objects in the room as the physician points to them
- Following simple instructions or writing a simple sentence
This test can also be used after diagnosis to evaluate the progression of dementia in the patient.
Additionally, blood and urine tests may be performed to test for conditions that cause dementia. These may include tests for vitamin deficiencies, poisoning or infections. A sample of spinal fluid may also be taken using a spinal tap to test for infections of the brain or spine.
Imaging tests, such as magnetic resonance imaging (MRI) tests and computed axial tomography (CAT) scans may be used to identify signs of brain abnormalities that may be the result of injury, stroke or a tumor. This enables physicians to identify the underlying cause of the dementia or to take steps towards preventing potential causes of dementia (e.g. strokes). However, imaging tests have limitations and are unable to identify many of the brain abnormalities that are the hallmark of progressive dementias such as the plaques and tangles of Alzheimer’s disease and the Lewy bodies of Lewy body dementia.
Treatment options for dementia
Treatment for dementia often relies on treating the underlying cause. If dementia is caused by medication interactions or drug or alcohol abuse, it may be possible to reverse the dementia by no longer taking the medication or substance. In some cases, dementia caused by a brain tumor or lesion may be treated and resolved by removing the tumor or lesion. However the damage the tumor or lesion caused to brain tissues and function can be permanent.
In the case of progressive dementias or dementias that are caused by brain injury, there is rarely a cure. However, there are treatment options available that can minimize or stabilize patients’ symptoms and in some cases delay the necessity of nursing home care.
There are certain medications that a physician may prescribe to try to reduce the symptoms of dementia. Some of these medications are designed to maintain the levels of a neurotransmitter in the brain called acetylcholine, which is important for brain function. Other medications work to regulate the function of the neurotransmitter glutamate, which is important for learning and memory.
Behavioral or psychiatric symptoms due to dementia may first be treated with non-drug methods. This usually includes identifying the trigger for the symptoms and attempting to resolve it. Many times this involves making adjustments to the environment that the patient lives in – for example, simplifying the environment or increasing the time between stimulating events (e.g. bath-time, getting dressed).
In addition to non-drug methods, a physician may recommend certain medications to control behavioral or psychiatric symptoms. It is important that these medications be used according to physician instructions. People with dementia are more likely to experience severe side effects from these medications than other people. Medications that may be prescribed for patients with behavioral or psychiatric symptoms include:
- Antidepressants to treat depression and low moods
- Anti-anxiety medications to treat anxiety or verbally disruptive behavior
- Anti-psychotic medication to treat hallucinations, delusions or aggression
- Sedatives to treat sleep problems
Some companies market herbal supplements as alternative treatment methods for dementia. However, in most cases, these treatments have not been thoroughly tested. In addition, unlike prescribed medication, they have not been approved and are not regulated by the Food and Drug Administration (FDA). It is important to discuss the use of alternative treatment methods with a physician before they are started. Some alternative remedies could interact with prescribed medication or lead to more serious health complaints.
Prevention methods for dementia
Many types of dementia are poorly understood by scientists and have few prevention methods. Vascular dementia is often caused by a stroke, therefore taking action to help protect the body against stroke may be an effective prevention method for this type of dementia. This can be achieved by eating a healthy diet, quitting smoking and controlling high blood pressure. Some studies have shown that controlling systolic blood pressure (the top number of a blood pressure reading) in people older than age 60 can help reduce the risk of dementia by up to 50 percent, according to the National Institute of Neurological Disorders and Stroke (NINDS).
Other potential prevention methods for dementia may include:
- Reducing cholesterol levels. Some studies have linked high cholesterol levels with an increased risk of Alzheimer’s disease.
- Lowering homocysteine. Related to high cholesterol levels, high homocysteine (an amino acid used to produce proteins) has also been linked to an increased risk of both Alzheimer’s disease and vascular dementia.
Scientific studies have also indicated that remaining physically and mentally active throughout life helps to keep the brain healthy, especially in later life. It is not known whether physical and mental activity directly reduces the risk of dementia, but scientists agree that it seems reasonable that keeping the body healthy will also keep the mind healthy.
Lifestyle considerations for dementia
Dementia can be frustrating and overwhelming for both the patient and the patient’s friends and family.
Dementia may affect many aspects of the patient’s life. If the disease progresses, the patient may not be able to drive or live independently. Daily activities can become more difficult and many people with dementia experience some form of depression. People with severe or degenerative dementias usually require constant supervision and care as the disease progresses to its latter stages. People with dementia may also need to live in a simplified environment, which may involve removing obstacles in the home that may cause harm, or moving the patient to a long-term care facility.
Individual or group therapy may be a valuable outlet for both the patient and the patient’s caregiver to discuss feelings of frustration or depression. It is important that the caregiver have scheduled time off from the often intense supervision of the person with dementia.
Questions for your doctor regarding dementia
Preparing questions in advance can help patients to have more meaningful discussions with healthcare professionals regarding their condition. Patients may wish to ask their doctor the following dementia-related questions:
- Am I at risk of dementia?
- How do you know that my symptoms are related to dementia?
- Is my dementia permanent or temporary?
- What caused my dementia?
- What type of dementia do I have?
- What tests will you use to diagnose dementia?
- At what stage is my dementia?
- Will you prescribe medication for my dementia?
- Are there any over-the-counter medications that I should avoid?
- Am I going to have to stop driving?
- Will I have to move out of my home?