Overview, Causes, & Risk Factors

Dementia is not a disease. It is a group of symptomsmarked by gradual changes in brain function and the ability to think, reason, andremember. Serious changes in memory, personality, and behaviorare the hallmarks of dementia.

What is going on in the body?

The ability of the brain to work correctly depends on acomplex communication system among billions of neurons, or brain cells.Certain parts of the brain are in charge of creating a memory.Others catalog this memory. Still others retrieve it. The way that a brainfunctions could be compared to the workings of a computer.

If an area of the brain in charge of these special functions is damaged, dementia may occur. Damage may be caused by infection, loss of blood supply, chemicals, or a genetic tendency for losing neurons. People normally lose a certain number of brain cells as they age. However, major losses cause progressive and widespread loss of normalbrain function.

In normal aging, memory lossis usually slow. It may result in forgetting names, phone numbers, or where anitem was just placed. Intelligence and problem-solving skills are not affected. True dementia involves loss of intelligence and problem-solving skills. It oftencannot be reversed and will become worse over time.

What are the causes and risks of the condition?

Dementia is always caused by an underlying disease orcondition. Brain tissue is damaged, and the ability to function decreases. Someof these conditions can be reversed, while others cannot. The most commoncause of dementia isAlzheimer disease.In this disease, changes in nerve cells in some parts of the brain result in the deathof large numbers of cells. The result is a progressive, but slow, decline in memory andthought processes.

Another common form of dementia is multi-infarct dementia. With this condition,small strokes or changes in the blood supply to the brain from the narrowingor hardening of arteries causes the deathof brain tissue. Symptoms will depend on what part of the brain tissue isdestroyed. These symptoms usually come on suddenly.

Other common causes are as follows:

  • Creutzfeldt-Jakob disease,a degenerative disorder of the nervous system that progresses quickly and causes problems with walking, talking, and the senses. When dementia occurs in young or middle-aged people, it is often due to this disease.
  • Huntington disease,a progressive disease causing brain cells to waste away that affects boththe body and the mind. It causes changes in thinking, memory, speech, judgment,and personality. Dementia often occurs in the later stages of the disease.Huntingdon Disease has been linked to a certain gene that a person can inherit.
  • Lewy body disease, a degenerative disease of the nervous system. Lewybodies are deposits of protein in nerve cells, often deep within the brains ofthose who also have Parkinson Disease. When these protein depositsoccur throughout the brain, dementia results. The course of illness is differentfrom Alzheimer’s disease, in that it results in changes in the speed of thought,memory, judgment, reasoning, and language. It can also cause a person to getlost easily. In addition, it may cause hallucinations.
  • Parkinson’s disease,a degenerative disorder of part of the nervous system. Up to 30 to 40 percentof people with this disease may develop dementia in the later stages.
  • Pick disease,also known as frontotemporal dementia, or FTD. FTD is a rare disorder of thebrain. It causes changes in personality, behavior, and memory over time. Itgets steadily worse, but it hard to diagnose until after death.

Other less common disorders that can cause dementia, ordementia-like behaviors include:

  • brain tumor
  • chronic subdural hematoma,a bleeding between the brain lining and brain tissue
  • HIV, theimmunodeficiency disorderthat leads to AIDS
  • multiple sclerosis,a disorder of the sheath that lines the brain and spinal cord
  • neurosyphilis,an infection of the nervous system by the Treponema pallidum\ bacteria. Less often, syphilis is transmitted from a pregnant woman to her baby. This form of syphilis is known as congenital syphilis
  • syphilis bacterium, which causes weakness and mental deterioration
  • normal pressure hydrocephalus,which is a build up of cerebrospinal fluid in the brain. This condition can often betreated through surgery to put a shunt tube in the brain that allows the excess fluidto flow out of the brain.
  • progressive supranuclear palsy,also known as Steele-Richardson-Olszewski syndrome, a rare disorder oflate middle age that causes widespread nervous system problems
  • stroke
  • viral or bacterial encephalitis,a swelling of the brain
  • Wilson disease,a rare disease causing an excess of copper in the liver, brain, kidneys,and corneas

Certain abnormal aspects of a person’s metabolism orhormones may also be responsible for the development of dementia,including the following:

  • chronic alcohol abuse
  • chronic exposure to metals, such as leador mercury, and to dyes, such as aniline
  • high-dose steroid abuse
  • hyperthyroidism,which means the thyroid gland is overactive
  • hypothyroidism,which means the thyroid gland is underactive
  • low body levels of B1 pantothenic acid folic acid

In some of these cases, dementia can be reversed byremoving the toxic agent or bringing vitamin levels back to a healthy range.

In older adults, depression and dementia are often mistaken foreach other. They do sometimes occur together, but depression is treatable,while dementia is not.

Symptoms & Signs

What are the signs and symptoms of the condition?

Symptoms of dementia often aren’t noticed right away. Or if they are, peoplesometimes assume that dementia is just a part ofaging.However, as more brain cells die, more brain functionsare lost, and symptoms become more severe. Common symptoms of dementiainclude the following:

  • being disoriented to time and place
  • changes in mood, including depressionand anxiety
  • delusions, or believing things that are not true
  • hallucinations, which include hearing, seeing, feeling, and smelling thingsthat do not exist
  • impaired ability to orient the body to the surrounding space
  • language breakdown, with slurred speech and trouble finding the right words
  • loss of bowel and bladder control
  • a loss of interest in activities that gave pleasure before
  • memory loss thataffects the person’s skills. Short-term memory, or memory of recent events, isparticularly affected in people with dementia.
  • misplacing belongings
  • personality changes, including agitation, irritability, paranoia, and hostility
  • poor or decreased judgment
  • trouble doing familiar activities

Sometimes, family members may not want to face how serioustheir loved one’s decline is. Doctors may misdiagnose the condition.

Diagnosis & Tests

How is the condition diagnosed?

Dementia can be diagnosed only if a doctor is made aware of theproblem. Diagnosis will start with a thorough physical and mental exam, aswell as the gathering of a detailed medical history. The family should beprepared to tell the doctor the range of the person’ssymptoms over time. The doctor will want to know how the symptomsprogressed and whether they have improved or become worse. Also, the familyshould report how suddenly or gradually symptoms appeared.

A complete list of all medicines the person is taking will beneeded. This includes over-the-counter products,herbal remedies,and prescription medicines. Combinations of drugs may impair thinkingat times.

To determine if other medical conditions may contribute to thesymptoms, the doctor may order certain tests, such as:

  • blood tests, such as a complete blood count, called aCBC,thyroid function tests,tests for infectious diseases, and tests to determine vitamin levels in theblood
  • memory testing
  • electroencephalogram, called an EEG, which measures brain waves
  • electrocardiogram, called an EKG,which measures the electrical activity of the heart
  • cranial MRI orcranial CT scans,which can be used to view the structures of the brain
  • spinal tap, aprocedure in which a small amount of fluid is withdrawn from the spinal columnto check for infection or bleeding

Since there is no definitive test for dementia in a living person,the doctor will try to rule out other conditions or diseases that maycause the symptoms.

Prevention & Expectations

What can be done to prevent the condition?

Most cases of dementia are caused byAlzheimer disease.Although there are no proven methods to prevent Alzheimer’s disease,recent research findings provide some options that may slow the onset of thedisease or how fast symptoms progress. These findings, which need furtherstudy, include the following:

  • low doses of aspirin and nonsteroidal anti-inflammatory drugs, calledNSAIDs, which may work by making blood cells and vessels less stickyand by improving blood flow
  • actively engaging in cognitive activities such as reading, which mayincrease the nerve connections in the brain and delay the onset of thedisease
  • taking antioxidants such as vitamin Eand selignine. In the Alzheimer Disease Cooperative Study, adose of 1,000 IU of vitamin E and 5 mg of selignine twice daily delayed nursinghome placement, loss of the ability to perform self-care, and severedementia.
  • hormone replacement therapyfor menopausalwomen, which may delay the onset of symptoms of Alzheimer disease.The relationship between the hormone estrogen and Alzheimer diseaseneeds further study.
  • avoiding head injuries. A person should wear a seat belt at all times whenriding in a motor vehicle. Sports safety guidelines forchildren,adolescents,and adultscan be helpful in avoiding other head injuries.

Strokes are another major cause of dementia. Preventing ortreating high blood pressure,obesity,diabetes,high cholesterol,and alcohol abusecan lower the risk of stroke.

What are the long-term effects of the condition?

Long-term progressive dementia results in the continuedloss of mental abilities. In the end, the person is unable to care for him orherself. A person suffering from the condition often requires nursinghome care. Falls, trauma, infections, anddepressionmay also result in a need for more intense medical care.

What are the risks to others?

Dementia poses no risk to others, except for the disruptionto home life and family relationships.

Treatment & Monitoring

What are the treatments for the condition?

Even when dementia is incurable, there are things that can bedone to treat the patient and help his or her family to cope. Medical careis crucial, both for the patient and to answer questions family may have.

In the early and middle stages of Alzheimer disease, medicinemay help. The three medicines currently approved by the Food andDrug Administration for treatment of Alzheimer disease are donepezil,tacrine, and rivastigmine. These medicines are designed to improvememory by increasing the amount of acetylcholine in the body.

Other medicines, such as risperidone or quetiapine, mayalso be used to help behavioral problems such as hallucinations,delusions, or agitation. Some people with dementia may also needmedicines for depression, acute situational anxiety, generalized anxiety disorder \ panic disorder \ post-traumatic stress disorder \ phobias \ obsessive compulsive disorders \ anxiety,or insomnia.

Eating a healthy diet and practicing healthy lifestyle habitscan also help any person to maintain health status. In addition, the person’scaregivers should work to maintain a daily routine, help the person to beas active as possible, and maintain social contacts. Memory aids such asposting big calendars, making lists of daily plans, and hanging up writtendirections for household tasks can help greatly.

Other treatments include support and education for those caringfor people with dementia. Individual and family counseling can help. Supportgroups have also been found to assist caregivers. As the disease progresses,many families are unable to provide home care for the person with dementia,and placement in a special facility is needed.

What are the side effects of the treatments?

Medicines used to treat dementia can damage the liver,so periodic liver function testsare needed. Other side effects may include:

  • nausea
  • diarrhea
  • insomnia
  • vomiting
  • fatigue
  • muscle cramps
What happens after treatment for the condition?

In most cases, dementia is a progressive disease without acure. Treatment is lifelong. Because the course of dementia is hard to predict,people with the condition should make plans for end-of-life care whilethey are still able to think clearly.

Some of the challenges that family membersmay face include:

  • promoting independence while making sure the person is safe
  • stopping the person from driving
  • finding supportive care among family, in an assisted living facility,or in a nursing home
  • making business decisions
  • determining executors of written wills and making sure that advanceddirectives are in the person’s patient file at his or her doctor’s office
How is the condition monitored?

A person with dementia needs to have regular visits to the doctorfor evaluation and treatment. From time to time,liver function testsmay be ordered if the person is taking one of the medicines that can causeliver damage. Any new or worsening symptoms should be reported to the doctor.

Article type: xmedgeneral