Lewy body dementia also known as dementia with lewy bodies is the second most common type of progressive dementia after alzheimers disease dementia protein deposits called lewy bodies develop in nerve cells in the brain regions involved in thinking memory and movement motor control. Dementia with lewy bodies occurs because of abnormal deposits of a protein called alpha synuclein that develop inside the brains nerve cells the deposits are called lewy bodies after the scientist who first described them dr freidrich heinrich lewy dementia with lewy bodies accounts for between 5 and 15 of all dementia cases. Dementia with lewy bodies dlb is a type of dementia accompanied by changes in sleep behavior cognition movement and autonomic bodily functionsmemory loss is not always an early symptom the disease worsens over time and is usually diagnosed when cognitive decline interferes with normal daily functioningtogether with parkinsons disease dementia dlb is one of the two lewy body dementias. Lewy body dementia lbd is a disease associated with abnormal deposits of a protein called alpha synuclein in the brain these deposits called lewy bodies affect chemicals in the brain whose changes in turn can lead to problems with thinking movement behavior and mood lewy body dementia is one of the most common causes of dementia