Dementia with Lewy Bodies (DLB) is now recognized as second only to Alzheimer's disease in causing degenerative dementia. The central clinical feature of DLB is a progressive, often rapid decline in brain function. Early in the disease this may not affect memory as much as other mental abilities. Problems with paying attention, organizing, and spatial skills may be affected first.
DLB is also unusual in that considerable variation in alertness and attention can occur throughout the day. Persons with DLB often have trouble with seeing things that aren't there (hallucinations) and believing things that aren't true (delusions), and may describe these things very clearly and in much detail. DLB also affects muscular activity, with most patients experiencing stiffness and tremors like those found in Parkinson's disease. Falls and passing out spells are also common. Depression is more often seen in DLB than in Alzheimer's disease. A disturbance in the dream phase (REM) of sleep also occurs.
DLB is important to identify when present, because persons affected have unusual sensitivity to the tranquilizers most often used for hallucinations (neuroleptics), and have severe adverse reactions when given these drugs. It is also felt that persons with DLB respond unusually well to the cholinesterase inhibitors used in treatment of Alzheimer's disease (Aricept, Exelon and Reminyl).
The speed of deterioration of DLB varies, but is generally faster than in Alzheimer's disease.