What causes Alzheimer's disease isn't known, but genetic factors play a role-the disease seems to run in some families and is caused or influenced by several specific gene abnormalities. In Alzheimer's disease, parts of the brain degenerate, destroying cells and reducing the responsiveness of the remaining ones to many of the chemicals that transmit signals in the brain.Abnormal tissues, called senile plaques and neurofibrillary tangles, and abnormal proteins appear in the brain and are recognizable by doctors during an autopsy.Lewy body dementia closely resembles Alzheimer's disease, although the microscopic changes found in the brain are different The second most cause of dementia is successive strokes. Since this type of dementia results from many small strokes the condition is known as multi-infarct dementia. Most people with multi-infarct dementia have high blood pressure or diabetes, both of which damage blood vessels in the brain.

Rosie L