Dementia with Lewy bodies is a less-common form of dementia than Alzheimer’s disease but has special considerations when it comes to treatment.
Dementia with Lewy bodies accounts for 5% to 15% of cases of dementia and shares characteristics with both Alzheimer's disease and Parkinson's disease. Proper diagnosis and treatment can help relieve symptoms and slow cognitive loss.
Lewy bodies -- named from Frederick Lewy, the physician who first identified them in 1912 while working in the laboratory of Dr. Alois Alzheimer -- are tiny spherical deposits of a protein called alpha-synuclein that are found in the brains of patients with dementia with Lewy bodies. The presence of Lewy bodies throughout the brain disrupts its normal functioning.
As with Alzheimer’s disease, people with dementia with Lewy bodies have cognitive impairment that worsens with time. But people with dementia with Lewy bodies are more likely to experience attention problems, hallucinations, and signs of Parkinson’s disease (such as shuffling gait; rigid, stooped posture; poor balance; and slowness). Falls, depression, and rapid-eye-movement sleep disorders are also typical of dementia with Lewy bodies.
No imaging tests have proven successful in differentiating dementia with Lewy bodies from Alzheimer’s, but examination of the brain at autopsy reveals Lewy bodies throughout the brain. Most people with dementia with Lewy bodies also have plaques and tangles, although few have the quantity of tangles found in Alzheimer’s.
Specialized treatment of dementia with Lewy bodies depends on the specific symptoms present. Both medication and self-care measures can be helpful. Cholinesterase inhibitors—which include Aricept (donepezil), Exelon (rivastigmine), and Razadyne (galantamine)—help improve fluctuating cognitive impairment, visual hallucinations, apathy, anxiety, and sleep disturbances. As with Alzheimer’s disease, the progression of dementia with Lewy bodies is not slowed by cholinesterase inhibitors. People with dementia with Lewy bodies are prone to gastrointestinal side effects and excessive salivation (which can lead to drooling) when taking cholinesterase inhibitors.
Some doctors prescribe Larodopa (levodopa), the anti-Parkinson’s disease drug, to treat motor symptoms of dementia with Lewy bodies. Because Larodopa can worsen hallucinations and delusions, the lowest acceptable dose should be used. Newer atypical antipsychotic drugs such as Zyprexa (olanzapine), Seroquel (quetiapine), and Risperdal (risperidone) can help minimize hallucinations and delusions but should be used with extreme caution to avoid marked worsening of Parkinson’s-like symptoms. Older antipsychotic drugs such as Haldol (haloperidol) should be avoided altogether. Self-care measures involve making changes in the patient’s environment or behavior. Some examples are adequate lighting to reduce visual hallucinations and daytime activity to improve disordered sleep.
