Lewy body dementia
Also Known As: Lewy body dementia, Dementia with Lewy bodies
Dementia with Lewy bodies (DLB), also known under a variety of other names including Lewy body dementia, diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type, is a type of dementia closely associated with Parkinson's disease. It is characterized anatomically by the presence of Lewy bodies, clumps of alpha-synuclein and ubiquitin protein in neurons, detectable in post mortem brain histology. Lewy body dementia affects 1.3 million individuals in the United States alone.
Lewy body dementia (LBD) is a progressive degenerative dementia of the elderly. Its primary feature is cognitive decline, particularly of executive functioning. The patient will display an inability to plan, or a loss of analytical or abstract thinking. Persons with LBD will show markedly fluctuating cognition. Wakefulness will vary from day to day, and alertness and short term memory will rise and fall. Persistent or recurring visual hallucinations with vivid and detailed pictures are often an early diagnostic symptom. REM sleep behavior disorder (RBD) is a symptom often first recognized by the patient's caretaker. RBD includes vivid dreaming, with persistent dreams, purposeful or violent movements, and falling out of bed. LBD symptoms overlap clinically with Alzheimer's disease and Parkinson's disease, but are more associated with the latter. Because of this overlap, Lewy Body Dementia is often misdiagnosed in its early years.
In LBD, loss of cholinergic (acetylcholine-producing) neurons is thought to account for degeneration of cognitive function (similar to Alzheimer's), while the death of dopaminergic (dopamine-producing) neurons appears to be responsible for degeneration of motor control (similar to Parkinson's) – in some ways, therefore, it resembles both diseases. The overlap of neuropathologies and presenting symptoms (cognitive, emotional, and motor) can make an accurate differential diagnosis difficult. In fact, it is often confused in its early stages with Alzheimer's disease and/or vascular dementia (multi-infarct dementia), although, where Alzheimer’s disease usually begins quite gradually, DLB often has a rapid or acute onset, with especially rapid decline in the first few months. DLB tends to progress more quickly than Alzheimer’s disease. Despite the difficulty, a prompt diagnosis of DLB is important because of the risks of sensitivity to certain neuroleptic drugs and because appropriate treatment of symptoms can improve life for both the person with DLB and their caregivers.
Benzodiazepines, anticholinergics, surgical anesthetics, some antidepressants, and OTC cold remedies can cause acute confusion, delusions and hallucinations.
DLB is distinguished from the dementia that sometimes occurs in Parkinson's disease by the time frame in which dementia symptoms appear relative to Parkinson symptoms. Parkinson's disease with dementia (PDD) would be the diagnosis when dementia onset is more than a year after the onset of Parkinson's. DLB is diagnosed when cognitive symptoms begin at the same time or within a year of Parkinson symptoms.