What Is Lewy Body Dementia (LBD)?

What Is Lewy Body Dementia (LBD)?

Lewy body dementia (LBD) is a disease that affects neurological function. It is linked to abnormal deposits of a protein in the brain called alpha-synuclein. These deposits, called Lewy bodies, affect chemicals in the brain and cause changes in thinking, movement, behavior, and mood.

There are two types of dementia: dementia with Lewy bodies and Parkinson’s disease dementia. Each is defined by the order in which motor and cognitive impairments occur. LBD is one of the most common causes of dementia.

LBD is a progressive disease. There is no cure for it currently, but research is ongoing.

Stages of Lewy Body Dementia


LBD is a progressive disease, with symptoms appearing slowly and worsening over time. LBD progression can be described by the stage of symptoms.

The stages of dementia are:

  • Early stage (mild symptoms). Those in the early stage of LBD may have mild symptoms, such as stiffness and difficulty moving their body, but are independent and can function normally.
  • Middle stage (moderate symptoms). LBD symptoms in the intermediate stage are more noticeable, and as they become more severe, will require people to seek more help with everyday tasks. Patients may start to have thinking, concentration, and memory problems similar to those in Alzheimer’s disease, along with hallucinations and changes in behavior. Patients often experience tremors and difficulty speaking.
  • Late stage (severe symptoms). In the final stage of dementia, people experience a severe decline. Individuals are confused, lose the ability to speak and walk, and may have delusions and paranoia. At this stage, patients require around-the-clock assistance with daily personal care.

Signs & Symptoms of Lewy Body Dementia


Lewy body dementia is a form of dementia caused by the decay of brain tissue. It is characterized by a buildup of protein particles called Lewy bodies in the brain. It is defined as dementia plus fluctuations (spontaneous changes in attention, cognition, and arousal), spontaneous parkinsonism (an umbrella term for brain conditions that cause stiffness, slowed movements, and tremors), and hallucinations.

The most common signs and symptoms of LBD include changes in thinking, behavior, mood, movement, and sleep. Not every patient has all the signs and symptoms.

  • Thinking ability (cognitive problems)
    • Thinking and organization – Difficulty thinking clearly, confusion, trouble planning, and communication issues
    • Concentration – Difficulty concentrating and paying attention, which can vary from day to day
  • Psychiatric
    • Visual hallucinations – Seeing things that aren’t there (a common symptom that starts early in the disease)
  • Movement
    • Rigidity – Stiff muscles
    • Shuffling – Slow walk
    • Balance problems – Falling and coordination issues
    • Tremors – Shaking hands
  • Sleep
    • Sleeping a lot during the daytime
    • Trouble falling or staying asleep
    • REM sleep behavior disorder – Acting out dreams, making movements during sleep, or falling out of bed
    • Restless legs syndrome – An urge to move the legs during sleep
  • Mood

What Causes Lewy Body Dementia?


The precise cause of LBD is unknown. The condition is linked to an accumulation of Lewy bodies in the brain. Lewy bodies are abnormal deposits of a protein in the brain called alpha-synuclein. Lewy bodies affect how the brain works and cause thinking, organization, and other problems. Most people will have similar symptoms to those of Alzheimer’s disease, though patients may not meet the criteria for Alzheimer’s disease.

Risk Factors for Lewy Body Dementia

Risk Factors

Risk factors that seem to increase the risk of developing Lewy body dementia include:

  • Age. The risk of developing LBD increases with age. People older than 60 are at greater risk.
  • Gender. LBD affects more biologically male people than biologically female people, as with Parkinson’s Disease, but unlike Alzheimer’s disease.
  • Family history. People who have a parent with LBD or Parkinson’s disease may be at increased risk of developing LBD.



As with other types of dementia, LBD affects the body, mental ability, and ability to function. LBD can make life more complicated for people with the condition and their caregivers. Everyday activities can become more challenging in the following ways:

  • Inability to take care of oneself — including difficulty in doing everyday activities, bathing, dressing, using the toilet, and taking medications — drastically alters the lives of people with LBD.
  • Changes in behavior and mental health, including confusion, agitation, aggression, depression, apathy, and changes in sleeping habits, are common in people with LBD.
  • Compromised personal safety is associated with confusion and poor judgment. For example, people with LBD may become confused and get lost even in familiar surroundings. Driving, living alone, cooking, handling money, and more can also put people with dementia symptoms at risk.
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Trust NewYork-Presbyterian for Lewy Body Dementia Care

Our team at NewYork-Presbyterian Hospital understands the toll that Lewy body dementia, Alzheimer’s disease, progressive dementia, and other neurological disorders can take on your quality of life and the lives of your family members. Contact us to make an appointment and learn more about the different options available for diagnosing Lewy body dementia.