Lewy Body Dementia

In Lewy body dementia, mental abilities decline because abnormal round deposits of protein (called Lewy bodies) develop in nerve cells throughout the brain.

Lewy bodies result in the death of nerve cells. Lewy bodies also develop in people with Parkinson's disease but only in one part of the brain.

Lewy body dementia is a relatively common dementia. It usually affects people over 65 and affects more men than women. Its cause is unknown.

Symptoms

The symptoms of Lewy body dementia are similar to those of Alzheimer's disease. They include memory loss, disorientation, and problems remembering, thinking, understanding, communicating, and controlling behavior. However, Lewy body dementia is more likely to cause psychotic symptoms, such as paranoia, delusions, and hallucinations. Hallucinations tend to develop earlier than in Alzheimer's disease. They are usually visual and often complex and detailed (including recognizable people and animals). They may be pleasant.

In the early stages of Lewy body dementia (unlike Alzheimer's disease), mental function varies from day to day, often dramatically. One day, people may be able to converse coherently. The next day, they may be inattentive, drowsy, and almost mute. Fainting is common.

People with Lewy body dementia, like those with Parkinson's disease, move slowly and sluggishly, shuffle when they walk, stoop over, and have stiff muscles. Consequently, the risk of falling is increased. Trembling (tremors) occurs in a few people, but it is milder than that in Parkinson's disease. After symptoms begin, people live about 6 to 12 years.

Diagnosis and Treatment

Once dementia is diagnosed, doctors suspect Lewy body dementia if the symptoms fluctuate and if the person has visual hallucinations and symptoms of Parkinson's disease.

Generally, treatment of Lewy body dementia is the same as that of all dementias. The same drugs used to treat Alzheimer's disease, particularly rivastigmine, may be helpful.

Using antipsychotic drugs to treat psychotic symptoms may make the tremors and other symptoms of Parkinson's disease much worse, sometimes resulting in death. Using drugs to treat the symptoms of Parkinson's disease may make the psychotic symptoms worse.