Is Lewy Body Dementia Hereditary?

Lewy body dementia (LBD) is the second most prevalent type of degenerative dementia in the US, after Alzheimer's disease. Over 1.4 million Americans are currently affected by LBD, representing roughly 4 to 16% of all diagnosed dementia cases.

Lewy body dementia is irreversible like Alzheimer's, so there's no cure. What’s more, the disease advances more quickly than Alzheimer's. A diagnosed person is expected to live around five to seven years after diagnosis. However, some treatments can help manage the symptoms.

Due to the spectrum of symptoms that affect cognition, behavior, and even sleep functions, doctors often misdiagnose LBD as a mental illness, more likely schizophrenia or a different type of dementia.

Learn more about LBD by knowing its stages, early symptoms, causes, and if—similar to Alzheimer's—the risk of diagnosis increases with genetics.

Stages of Lewy Body Dementia

LBD has a similar disease progression to Alzheimer's, but manifesting symptoms are different. As standard in dementia, LBD symptoms are also categorized into early (mild), middle (moderate), and later (severe) stages based on the severity.

Symptoms in the mild category have the least impact on the day-to-day life of the affected person. A person with mild LBD can still have a good level of self-sufficiency and autonomy. Meanwhile, severe symptoms at the later stage have the most significant declining effect on overall physical and cognitive functions. The patient becomes wholly dependent on their caregivers.

Doctors use the same Global Deterioration Scale (GDS) in measuring Alzheimer's symptoms severity to assess LBD symptoms and get a precise disease stage. Stages 1 to 3 are the pre-dementia period, and Stages 4 to 7 are the dementia period.

Lewy Body Dementia Symptoms

In general, three symptoms differentiate LBD from other dementia types, and they are:

1. Frequent visual hallucinations

2. Motor impairment resembling the symptoms of Parkinson's disease

3. Fluctuating cognitive functions

Here's a summary of what each stage of symptoms looks like for individuals diagnosed with LBD:

Early Stage

Early in the course of LBD, there are five warning signs that include:

• Hallucinations or delusions (usually visual)
• Changes in movement (e.g. minor problems with balance that leads to falls, difficulty walking)
• Fluctuations in cognitive ability (e.g. trouble focusing on daily tasks)
• Sleep disorders (e.g. restless leg syndrome, sleepwalking, insomnia)
• Changes in behavior and mood (e.g. paranoia, anxiety, and depression)

The inconsiderable problems with movement, such as slowed walking, bent posture, and muscle stiffness, are often overlooked, but after some years, they become severe.

One quality of LBD that’s distinct from Alzheimer’s is that forgetfulness or memory loss may not be evident at the early stage.

Middle Stage

Indications of the disease become more pronounced as it progresses. Moreover, they will mirror symptoms of Parkinson's disease. The two conditions are related because the majority of those with Parkinson's have the same abnormal protein clumps called "Lewy bodies" in their brains. These clumps of alpha-synuclein protein cause the shared motor and cognitive deterioration in both cases of Parkinson's and LBD.

In the middle stage, brain functions decline further. Symptoms include:

• Falls
• Speech
• Problems with swallowing
• Worsening of motor problems
• Paranoia and delusions

Later Stage

The final stage is where symptoms are at the extremes; the person entirely depends on others to do their entire day's routines and tasks. One may also possibly develop Akinesia—a condition that describes the lost ability of the muscles to move, leading to paralysis.

The person in the later stage of LBD develops significant dysfunction in the following areas:

• Thinking, mood, and behavior (e.g. apathy, depression)
• Speech ability (i.e. talking is tough)
• Visuospatial ability
• Autonomic functions (i.e., ability to control unconscious body functions, such as breathing, digestion, and regulating heart rate)
• Movement functions (e.g. extreme rigidity on the torso, higher risk of falls)

LBD has a rapid progression. As it weakens the body’s ability to fight infections, coexisting conditions, specifically pneumonia, make it very challenging for the person to live longer. Pneumonia is the most cited cause of fatality for LBD.

Causes of Lewy Body Dementia

Like general dementia, experts haven't discovered the exact cause of LBD. However, specific risk factors can elevate the risk.

Age

Early signs of LBD start to manifest in people aged 50 and older.

Gender

More men than women have been diagnosed with LBD.

Genetics

There's no solid proof that confirms LBD runs in the family. In fact, according to Alzheimers.gov, most LBD cases don't have to do with genes.

Nevertheless, people with a history of LBD or Parkinson's disease have a higher risk, although this is rare.

Understanding the Link between Genetics and Lewy Body Dementia

Based on a genetic study by the National Institutes of Health, experts suspect that five genes can determine if a person inherits LBD.

1. Alpha-synuclein (SNCA)
2. Apolipoprotein E (APOE)
3. BIN1
4. GBA
5. Transmembrane protein 175 (TMEM175)

Mutations, variants, or changes in the activity of these genes can escalate the risk of LBD and other types of dementia.

Family with Lewy Body Dementia History Have a Higher Risk

LBD remains understudied, with scarce information about its genetic factor. Regardless, one thing remains essential—if any of your family relatives have had a history of Lewy body dementia or even other types of brain condition, it’s safer to assume that the risk is higher compared to those without a health history.

Being smart with your food choices, exercising, and leading a positive lifestyle are the natural remedies to minimize your risk for dementia.

Need advice on housing options for a loved one living with mild dementia? Get in touch with our dementia care specialists at Senex Memory Advisors, and we’ll help you find memory care communities near you.