DLB patients lose both. Despite these differences, a diagnosis of Dementia with Lewy Bodies does not preclude a positive diagnosis of Alzheimer's, Parkinson's or other diseases common in older age. With an average lifespan after onset of 5 to 7 years, the progress of Dementia with Lewy Bodies is relentless, resulting in severe dementia and immobility. DLB does not follow a pattern of stages as is seen in some other dementias. A few patients progress very rapidly through the disease.
Death usually occurs from pneumonia or other illness.
There is no cure nor specific treatment to arrest the course of the disease. Caution must be used in treating a person who is suspected of having DLB, again pointing to the need for an accurate diagnosis. Likewise, levodopa drugs used to treat Parkinson's motor symptoms may increase the hallucinations of DLB patients and aggravate other symptoms. Levodopa is not usually very helpful in treating the motor symptoms of DLB patients. Some drug therapies are showing promise, however.