Dementia With Lewy Bodies and Parkinson Disease Dementia

The symptoms of dementia with Lewy bodies are very similar to those of Alzheimer disease. They include memory loss, disorientation, and problems remembering, thinking, understanding, communicating, and controlling behavior. But dementia with Lewy bodies can be distinguished by the following:

• In the early stages, mental function fluctuates, often dramatically, over a period of days to weeks but sometimes from moment to moment. One day, people may be alert and able to pay attention and converse coherently, and the next day, they may be drowsy, inattentive, and almost mute. People may stare into space for long periods.

• At first, attention and alertness may be more impaired than memory, including memory for recent events. In the early stages of this dementia, memory problems may result more from lack of attention than from actual problems remembering. More noticeable memory problems tend to occur later as the dementia progresses.

• People have difficulty planning, solving problems, handling complex tasks (such as managing a bank account), and using good judgment (called executive function).

• The ability to copy and draw may be impaired more severely than other brain functions.

• Psychotic symptoms, such as hallucinations, delusions, and paranoia, are more common in dementia with Lewy bodies, and hallucinations tend to occur earlier.

In dementia with Lewy bodies, hallucinations are usually visual ones, which are often complex and detailed. They may include recognizable animals or people. The hallucinations are often threatening. Over half of people who have dementia with Lewy bodies have complex, bizarre delusions. Instead of relieving these symptoms, antipsychotic medications often make them and other symptoms worse or have other severe, sometimes life-threatening side effects, such as neuroleptic malignant syndrome.

Like people who have Parkinson disease, people who have dementia with Lewy bodies have stiff muscles, move slowly and sluggishly, shuffle when they walk, and stoop over. Balance is easily lost, making falls more likely. Tremor also develops, but it usually develops later and causes fewer problems than it does in Parkinson disease. Problems with thinking and problems with muscles and movement usually begin within 1 year of each other.

Sleep problems are common. Many people with dementia with Lewy bodies have rapid eye movement (REM) sleep behavior disorder. People with this disorder act out their dreams, sometimes injuring their bed partner.

The autonomic nervous system may malfunction, preventing the body from regulating internal functions, such as blood pressure and body temperature. As a result, people may faint, sweat too much or too little, have a dry mouth, or have urinary problems or constipation.

After symptoms appear, people usually live about 6 to 12 years.

In Parkinson disease dementia (unlike in dementia with Lewy bodies), mental function typically begins to deteriorate about 10 to 15 years after problems with muscles and movement appear.

As in other dementias, many mental functions can be affected. Memory is impaired, and people have difficulty paying attention and processing information. People think more slowly. Problems with planning and doing complex tasks occur earlier and are more common than in Alzheimer disease.

Hallucinations and delusions are less common and/or less severe than in dementia with Lewy bodies.

In Parkinson disease dementia, problems with balance and walking and falls are more common, and muscle problems (such as stiffness and slowed movements) worsen more rapidly than in Parkinson disease without dementia.

A diagnosis of dementia is based on the following:

• Symptoms, which are identified by asking the person and family members or other caregivers questions

• Results of a physical examination

• Results of a mental status test

• Results of additional tests, such as computed tomography (CT) or magnetic resonance imaging (MRI)

The mental status test, consisting of simple questions and tasks, helps doctors determine whether people have dementia.

Neuropsychologic testing, which is more detailed, is sometimes needed. This testing covers all the main areas of mental function, including mood, and usually takes 1 to 3 hours. This testing helps doctors distinguish dementia from age-associated memory impairment, mild cognitive impairment, and depression.

Information from the above sources helps doctors usually rule out delirium as the cause of symptoms (see table Comparing Delirium and Dementia). Doing so is essential because delirium, unlike dementia, can often be reversed if promptly treated.

Distinguishing delirium from dementia with Lewy bodies is particularly important because in both, mental function also fluctuates.

Doctors base the diagnosis of dementia with Lewy bodies on its characteristic symptoms. Dementia with Lewy bodies is likely if mental function fluctuates in people who have visual hallucinations and muscle and movement symptoms similar to those caused by Parkinson disease.

Computed tomography (CT) and/or magnetic resonance imaging (MRI) may be done to rule out other causes of dementia.

Other imaging tests may help doctors diagnose dementia with Lewy bodies. They include positron emission tomography (PET) and single-photon emission CT (SPECT). These tests use a substance containing a radioactive tracer that, when injected into a vein, collects in a particular organ. A gamma-ray camera attached to a computer detects the radioactivity, and the computer produces an image of the organ being examined.

However, even after testing, distinguishing dementia with Lewy bodies from Parkinson disease dementia can be difficult because symptoms are similar:

• Generally, dementia with Lewy bodies is more likely if movement and muscle problems develop at the same time or shortly after mental function starts to decline.

• Parkinson disease dementia is more likely if mental decline occurs years after muscle and movement problems develop in people with Parkinson disease and if muscle and movement symptoms are more severe than mental impairment.

However, the diagnosis of these dementias can be confirmed definitively only when a sample of brain tissue is removed and examined under a microscope. This procedure is done after death during an autopsy.

Creating a safe and supportive environment can be very helpful.

Generally, the environment should be bright, cheerful, safe, stable, and designed to help with orientation. Some stimulation, such as a radio or television, is helpful, but excessive stimulation should be avoided.

Structure and routine help people stay oriented and give them a sense of security and stability. Any change in surroundings, routines, or caregivers should be explained to people clearly and simply.

Following a daily routine for tasks such as bathing, eating, and sleeping helps people with Alzheimer disease remember. Following a regular routine at bedtime may help them sleep better.

Activities scheduled on a regular basis can help people feel independent and needed by focusing their attention on pleasurable or useful tasks. Such activities should include physical and mental activities. Activities should be broken down in small parts or simplified as the dementia worsens.

The same medications used to treat Alzheimer disease

Medications used to treat Parkinson disease may help relieve the symptoms of Parkinson disease (such as stiff muscles and tremor) in both dementias. However, in dementia with Lewy bodies, these medications may worsen confusion, hallucinations, and delusions.

In dementia with Lewy bodies, older antipsychotic medications tend to worsen muscle and movement symptoms and are best avoided. Newer antipsychotic medications, given in low doses, are preferred. However, newer antipsychotic medications, if used for a long time, may cause weight gain and abnormal fat (lipid) levels (hyperlipidemia) and increase the risk of type 2 diabetes.

Caring for people with dementia is stressful and demanding, and caregivers may become depressed and exhausted, often neglecting their own mental and physical health. The following measures can help caregivers (see table Caring for Caregivers):

• Learning about how to effectively meet the needs of people with dementia and what to expect from them: Caregivers can get this information from nurses, social workers, organizations, and published and online materials.

• Seeking help when it is needed: Caregivers can talk to social workers (including those in the local community hospital) about appropriate sources of help, such as day-care programs, visits by home nurses, part-time or full-time housekeeping assistance, and live-in assistance. Counseling and support groups can also help.

• Caring for self: Caregivers need to remember to take care of themselves. They should not given up their friends, hobbies, and activities.

Before people with dementia with Lewy bodies or Parkinson disease dementia become too incapacitated, decisions should be made about medical care, and financial and legal arrangements should be made. These arrangements are called advance directives. People should appoint a person who is legally authorized to make treatment decisions on their behalf (a health care proxy). They should discuss their health care wishes with this person and their doctor. Such issues are best discussed with all concerned long before decisions are necessary.

As the dementia worsens, treatment tends to be directed at maintaining the person’s comfort rather than at attempting to prolong life.