Lewy Body Dementia (LBD)

Lewy Body Dementia (LBD)

Understanding Lewy Body Dementia (LBD)

Lewy body dementia (LBD) is a progressive brain disorder caused by the abnormal buildup of a protein called alpha-synuclein, also known as Lewy bodies. These protein deposits affect areas of the brain involved in thinking, movement, behavior, and sleep.

LBD is the second most common progressive dementia after Alzheimer’s disease, affecting more than 1.4 million people in the United States. Symptoms often fluctuate, meaning a person’s alertness, attention, and thinking ability can vary significantly from hour to hour or day to day.

Because LBD shares features with Alzheimer’s disease, Parkinson’s disease, and certain psychiatric conditions, early diagnosis can be challenging.

Understanding Lewy Body Dementia (LBD)

Lewy body dementia (LBD) is a progressive brain disorder caused by the abnormal buildup of a protein called alpha-synuclein, also known as Lewy bodies. These protein deposits affect areas of the brain involved in thinking, movement, behavior, and sleep.

LBD is the second most common progressive dementia after Alzheimer’s disease, affecting more than 1.4 million people in the United States. Symptoms often fluctuate, meaning a person’s alertness, attention, and thinking ability can vary significantly from hour to hour or day to day.

Because LBD shares features with Alzheimer’s disease, Parkinson’s disease, and certain psychiatric conditions, early diagnosis can be challenging.

Brain Changes in Lewy Body Dementia

In Lewy body dementia, alpha-synuclein accumulates in multiple brain regions, including:

  • Cerebral cortex, affecting thinking, perception, and behavior
  • Brainstem, which helps regulate sleep, blood pressure, and other automatic body functions
  • Limbic system, involved in emotions and memory
  • Basal ganglia, deep brain structures that control movement and can cause Parkinson-like symptoms

Some individuals with LBD also have brain changes seen in Alzheimer’s disease, such as amyloid plaques and tau tangles, which may worsen cognitive symptoms.

Brain Changes in Lewy Body Dementia

In Lewy body dementia, alpha-synuclein accumulates in multiple brain regions, including:

  • Cerebral cortex, affecting thinking, perception, and behavior
  • Brainstem, which helps regulate sleep, blood pressure, and other automatic body functions
  • Limbic system, involved in emotions and memory
  • Basal ganglia, deep brain structures that control movement and can cause Parkinson-like symptoms

Some individuals with LBD also have brain changes seen in Alzheimer’s disease, such as amyloid plaques and tau tangles, which may worsen cognitive symptoms.

Clinical Features of Lewy Body Dementia

Lewy body dementia affects multiple systems in the body. Symptoms generally fall into several key categories.

Many people with LBD develop Parkinsonian features, including slowness of movement, muscle stiffness, tremor, and balance problems that can lead to falls. Facial expression may become reduced, and walking may appear shuffling.

These symptoms occur when Lewy bodies damage brain regions responsible for movement control.

Cognitive symptoms in LBD can resemble Alzheimer’s disease but often have distinguishing features. Individuals may experience fluctuating attention and alertness, slowed thinking, difficulty with planning or decision-making, and problems with visual or spatial tasks such as judging distance.

Memory problems may occur but are often less prominent early in the illness compared to Alzheimer’s disease.

Behavioral and psychiatric symptoms are common and may include vivid visual hallucinations, delusions, depression, anxiety, apathy, or reduced motivation.

People with LBD may be especially sensitive to certain psychiatric medications, which can worsen movement or cognitive symptoms. Careful medication management is essential.

Sleep disturbances are a hallmark of LBD and may appear years before cognitive symptoms.

REM Sleep Behavior Disorder (RBD) involves physically acting out dreams, such as talking, yelling, or striking movements during sleep. A history of RBD is a strong indicator of synuclein-related diseases, including LBD, though not all individuals experience it.

Other sleep issues may include excessive daytime sleepiness, insomnia, or restless sleep.

Lewy bodies can affect the autonomic nervous system, leading to symptoms such as drops in blood pressure when standing, constipation, urinary problems, sexual dysfunction, temperature regulation issues, drooling, or swallowing difficulties.

These symptoms can significantly impact daily life and often require targeted treatment.

Clinical Features of Lewy Body Dementia

Lewy body dementia affects multiple systems in the body. Symptoms generally fall into several key categories.

Many people with LBD develop Parkinsonian features, including slowness of movement, muscle stiffness, tremor, and balance problems that can lead to falls. Facial expression may become reduced, and walking may appear shuffling.

These symptoms occur when Lewy bodies damage brain regions responsible for movement control.

Cognitive symptoms in LBD can resemble Alzheimer’s disease but often have distinguishing features. Individuals may experience fluctuating attention and alertness, slowed thinking, difficulty with planning or decision-making, and problems with visual or spatial tasks such as judging distance.

Memory problems may occur but are often less prominent early in the illness compared to Alzheimer’s disease.

Behavioral and psychiatric symptoms are common and may include vivid visual hallucinations, delusions, depression, anxiety, apathy, or reduced motivation.

People with LBD may be especially sensitive to certain psychiatric medications, which can worsen movement or cognitive symptoms. Careful medication management is essential.

Sleep disturbances are a hallmark of LBD and may appear years before cognitive symptoms.

REM Sleep Behavior Disorder (RBD) involves physically acting out dreams, such as talking, yelling, or striking movements during sleep. A history of RBD is a strong indicator of synuclein-related diseases, including LBD, though not all individuals experience it.

Other sleep issues may include excessive daytime sleepiness, insomnia, or restless sleep.

Lewy bodies can affect the autonomic nervous system, leading to symptoms such as drops in blood pressure when standing, constipation, urinary problems, sexual dysfunction, temperature regulation issues, drooling, or swallowing difficulties.

These symptoms can significantly impact daily life and often require targeted treatment.

Types of Lewy Body Dementia

There are two closely related diagnoses within Lewy body dementia.

Dementia with Lewy Bodies (DLB)
Cognitive symptoms such as fluctuations, hallucinations, and attention problems appear before or within one year of movement symptoms. Motor symptoms may be mild early on.

Parkinson’s Disease Dementia (PDD)
Parkinsonian movement symptoms begin years before cognitive decline. Dementia developing more than one year after the onset of Parkinson’s disease is classified as PDD.

Both conditions are caused by the same underlying process: the accumulation of Lewy bodies in the brain.

Types of Lewy Body Dementia

There are two closely related diagnoses within Lewy body dementia.

Dementia with Lewy Bodies (DLB)
Cognitive symptoms such as fluctuations, hallucinations, and attention problems appear before or within one year of movement symptoms. Motor symptoms may be mild early on.

Parkinson’s Disease Dementia (PDD)
Parkinsonian movement symptoms begin years before cognitive decline. Dementia developing more than one year after the onset of Parkinson’s disease is classified as PDD.

Both conditions are caused by the same underlying process: the accumulation of Lewy bodies in the brain.

Risk Factors for Lewy Body Dementia

The exact cause of LBD is unknown, but risk factors include increasing age (typically over 60), male sex, a history of REM Sleep Behavior Disorder, family history of Parkinson’s disease or LBD, and certain genetic variants such as GBA or SNCA. Most cases are not strongly inherited.

How Lewy Body Dementia Is Diagnosed

Diagnosis is based on clinical symptoms and supported by specialized testing. Core features doctors look for include fluctuating cognition, visual hallucinations, REM Sleep Behavior Disorder, and Parkinsonian motor symptoms.

Additional tests may help support the diagnosis or distinguish LBD from other dementias.

DATscan measures dopamine activity in the basal ganglia. Reduced uptake is commonly seen in LBD and Parkinson’s disease but not in Alzheimer’s disease, making this scan helpful when motor symptoms are subtle or unclear.

CSF testing may show Alzheimer’s disease biomarkers that are normal or only mildly abnormal in LBD. Research-level tests can detect synuclein markers, though these are not yet widely available.

A newer diagnostic approach involves taking small skin samples to detect abnormal phosphorylated alpha-synuclein in peripheral nerves. This test is increasingly used in specialty centers and can support diagnosis in complex cases.

Risk Factors for Lewy Body Dementia

The exact cause of LBD is unknown, but risk factors include increasing age (typically over 60), male sex, a history of REM Sleep Behavior Disorder, family history of Parkinson’s disease or LBD, and certain genetic variants such as GBA or SNCA. Most cases are not strongly inherited.

How Lewy Body Dementia Is Diagnosed

Diagnosis is based on clinical symptoms and supported by specialized testing. Core features doctors look for include fluctuating cognition, visual hallucinations, REM Sleep Behavior Disorder, and Parkinsonian motor symptoms.

Additional tests may help support the diagnosis or distinguish LBD from other dementias.

DATscan measures dopamine activity in the basal ganglia. Reduced uptake is commonly seen in LBD and Parkinson’s disease but not in Alzheimer’s disease, making this scan helpful when motor symptoms are subtle or unclear.

CSF testing may show Alzheimer’s disease biomarkers that are normal or only mildly abnormal in LBD. Research-level tests can detect synuclein markers, though these are not yet widely available.

A newer diagnostic approach involves taking small skin samples to detect abnormal phosphorylated alpha-synuclein in peripheral nerves. This test is increasingly used in specialty centers and can support diagnosis in complex cases.

Learn More About Lewy Body Dementia

Learn More About Lewy Body Dementia

Looking for More Info on Dementia and Alzheimer’s Disease?

contact@clevelandadrc.org

Looking for More Info on Dementia and Alzheimer’s Disease?

contact@clevelandadrc.org

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