What are the differences in the following: dementia, Lewy Body dementia, and Alzheimer's?

Dementia is a category of disease, not a diagnosis. It indicates that there are problems with cognition severe enough to interfere with daily function.

AD is the most common form of dementia. It is characterized by plaques (beta amyloid) that form outside the neuron, and tangles (tau tangles) that form inside the neuron. The neuron subsequently dies, and the surround structures of the brain are affected until the brain can no longer sustain life. There are three forms of AD, and one subtype.

Lewy Body Dementia is the third most commonly occurring dementia. Lewy bodies are deposits of alpha-synuclein in the brain. If those deposits form and stay in the substantia nigra, it is Parkinson’s disease. If they form elsewhere in the brain, it is LBD. LBD is characterized by psychiatric features, and does not progress in the same manner as AD (which has a fairly predictable progression). LBD is misdiagnosed about 25% of the time. Having an accurate diagnosis for this form of dementia is critical because of the tx that is often used for the psychiatric features. If first generation psychotropics are used, the disease can be exacerbated and the person can actually die from the administration of those types of drugs.

There are many more specifics for each of these two forms of dementia. Just know that they are two completely different diseases, but each impairs all aspects of functioning, not just memory (a common misconception).


Reference: Kay Dee