Lewy Body Dementia: Types, Symptoms and Treatment

Lewy body dementia (LBD) is one of the most common types of dementia in older adults. Dementia is a loss of mental functions severe enough to affect daily life — memory, language, visual perception (making sense of what you see), problem solving, everyday tasks, and focus and attention.

Two types

Both types cause the same changes in the brain and, over time, similar symptoms. What differs is when thinking problems and movement problems begin.

Cause and risk

LBD happens when Lewy bodies — abnormal deposits of a protein called alpha-synuclein — build up in parts of the brain that control memory, thinking and movement. Researchers don't know exactly why they form, but other diseases, including Parkinson's disease, also involve a build-up of this protein.

Age is the biggest risk factor: most people who get LBD are over 50. A family history of LBD also raises the risk.

Symptoms

LBD is progressive: symptoms start slowly and worsen. The most common involve thinking, movement, sleep and behavior:

• Dementia.
• Swings in concentration, attention, alertness and wakefulness, usually from day to day but sometimes within a single day.
• Visual hallucinations — seeing things that aren't there.
• Parkinsonian movement symptoms — slowness, difficulty walking and muscle stiffness.
• REM sleep behavior disorder, in which a person seems to act out dreams, with vivid dreaming, sleep talking, violent movements or falling out of bed. In some people this is the earliest symptom, appearing several years before any other.
• Changes in behavior and mood, such as depression, anxiety and apathy (losing interest in normal daily activities).

Early on, symptoms can be mild and people can function fairly normally. As the disease advances, they need more help, and in the later stages they often cannot care for themselves.

Diagnosis

No single test diagnoses LBD, so it matters to see an experienced doctor, usually a specialist such as a neurologist. The doctor will:

• take a detailed medical history and account of symptoms, talking to both the patient and caregivers;
• do physical and neurological exams;
• rule out other conditions with similar symptoms, using tests that may include blood tests and brain imaging;
• test memory and other thinking skills with neuropsychological tests.

LBD can be hard to tell apart from Parkinson's and Alzheimer's disease, which cause similar symptoms; scientists think Lewy body disease may be related to them, or that they sometimes occur together. Knowing the type helps the doctor treat its particular symptoms and understand how it will progress. The type depends on timing:

• thinking problems starting within a year of movement problems → dementia with Lewy bodies;
• thinking problems starting more than a year after movement problems → Parkinson's disease dementia.

Treatment

There is no cure, but treatments can ease symptoms:

• Medicines for some thinking, movement and psychiatric symptoms.
• Physical therapy for movement problems.
• Occupational therapy to make everyday activities easier.
• Speech therapy for trouble swallowing or speaking loudly and clearly.
• Mental health counseling to help people with LBD and their families manage difficult emotions and behaviors and plan for the future.
• Music or art therapy, which may reduce anxiety and improve well-being.

Support groups offer emotional and social support to people with LBD and their caregivers, and a place to share tips for daily challenges.

Sources

• MedlinePlus, National Library of Medicine: "Lewy Body Dementia," with information from the National Institute of Neurological Disorders and Stroke, National Institutes of Health.