Lewy Body Dementia – Description, Causes, and Prevention.

Lewy body dementia – Overview

Lewy body dementia, also known as dementia with Lewy bodies, is the second most common type of progressive dementia after Alzheimer’s disease. Protein deposits, called Lewy bodies, develop in nerve cells in the brain regions involved in thinking, memory and movement (motor control).

Lewy body dementia causes a progressive decline in mental abilities. People with Lewy body dementia might have visual hallucinations and changes in alertness and attention. Other effects include Parkinson’s disease signs and symptoms such as rigid muscles, slow movement, walking difficulty and tremors.

 

What are the types of Lewy body dementia (LBD)?

Lewy body dementia (LBD) is one of the most common types of dementia, after Alzheimer’s disease. It usually happens to people who are 50 or over. There are two types:

• Dementia with Lewy bodies often starts when you have a hard time moving your body. Within a year, you start to have thinking and memory problems that are similar to Alzheimer’s disease, along with changes in behavior. You also might see things that aren’t there, called hallucinations.
• Parkinson’s disease dementia first causes movement problems. Trouble with memory happens much later in the disease.

Right now, there’s no cure for Lewy body dementia. But there are ways to ease symptoms for a while. Scientists are also getting better at understanding the differences between LBD and other conditions.

Pathophysiology

The distinguishing feature of LDB is the aggregation of Lewy bodies inside neurons of the cerebral cortex. An increase in Lewy bodies in the temporal lobe is associated with early occurrences of visual hallucinations – a hallmark of DLB. Additionally, increased Lewy body densities in the limbic and frontal lobes also correlate strongly with the severity of dementia. Although much of DLB remains unsolved, recent research has shed light on potential density-location relationships that have assisted clinicians in diagnosing and managing DLB.

The alpha-synuclein protein has been proven to be important in many functions in the brain, particularly at synapses. Alpha-synuclein aggregate into clumps called Lewy Bodies within neurons. These Lewy Bodies alter chemicals in the brain and can damage neurons which can eventually lead to the death of those neurons.

Postmortem studies have shown that the development of Lewy Bodies can occur in the substantia nigra, locus coeruleus, dorsal raphe, substantia innominate and dorsal motor nucleus of cranial nerve X.

Regions of the brain affected by LBD include:

• Cerebral cortex
• Limbic cortex
• Hippocampus
• Midbrain
• Brainstem

What are the causes of Lewy body dementia?

The precise cause of LBD is unknown, but scientists are learning more about its biology and genetics. For example, we know that an accumulation of Lewy bodies is associated with a loss of certain neurons in the brain that produce two important chemicals that act as messengers between brain cells (called neurotransmitters). One of these messengers, acetylcholine, is important for memory and learning. The other, dopamine, plays an important role in behavior, cognition, movement, motivation, sleep, and mood.

Who’s at risk?

Not everyone with PD will develop LBD, but having Parkinson’s may increase your risk of LBD.

A review indicates as many as 78 percent of PD patients experience dementia, and it is more likely as you age. LBD tends to affect people over 55 years old.

The same study identified additional risk factors for LBD in PD. They include:

• Male gender
• Changes in posture
• Instability with walking
• Greater difficulty with movement
• Symptoms seen on the left and right sides of the body
• Experiencing hallucinations earlier
• Symptoms not responding to medication

What are the symptoms of Lewy body dementia (LBD)?                       

Lewy body dementia (LBD) symptoms may resemble those of other neurological disorders, like Alzheimer’s disease and Parkinson’s disease. LBD affects each person differently, and symptoms vary in severity.

Common symptoms of LBD include:

• Decline in thinking, including memory, planning, problem solving, decision making and ability to focus and to understand information in visual form.
• Visual hallucinations, or seeing things that are not there.
• Reduced alertness, attention and ability to concentrate.
• Parkinsonism, a movement disorder with symptoms including slowness, tremors, stiffness, balance problems, soft voice, difficulty swallowing, reduced facial expression and shuffling walk.
• Visuospatial difficulties, including decreased depth perception, trouble recognizing familiar objects and impaired hand-eye coordination.
• Delusions, or beliefs with no basis in reality.
• Changes in behavior and mood including anxiety, agitation, aggression, apathy, depression and paranoia.
• Changes in sleep patterns.

Other symptoms include:

• Acting out while sleeping. Your loved one may act out their dreams during a phase of sleep cycle called rapid eye movement (REM). Sometimes this happens years before their LBD diagnosis. Often called REM sleep behavior disorder (RBD), this condition is described as frequent movements, such as flailing or punching, with yelling or speaking while sleeping. People living with RBD often have difficulty separating dreams from reality when they wake up.
• Changes in normal body functions. Body temperature may waver, blood pressure may fluctuate (causing fainting episodes and falls) and loss of bowel and bladder control.

Lewy body dementia – Complications and outlook

LBD is a progressive condition, with symptoms getting worse over time. Complications that can arise as a result include:

• Changes in mood, including depression, anxiety, and aggression
• Loss of mobility
• Increased risk of falls and injury
• Worsening dementia

On average, the life expectancy after receiving a diagnosis is 5–8 years, although this can from 2 to 20 years.

How is Lewy body dementia diagnosed?

Early diagnosis is essential because some drugs used to treat PD and AD can worsen LBD. However, early diagnosis is not easy, since no single test can accurately diagnose LBD.

Here are some of the exams and tests that can help your doctor arrive at the correct diagnosis.

Physical exam

When you visit a neurologist, they will perform a physical exam. A neurologist is a doctor who specializes in treating nervous system conditions. They’ll test the different ways your brain responds and how well it is working.

Physical examination may include testing of:

• heart rate and blood pressure
• muscle tone and strength
• reflexes
• balance and coordination
• sense of touch
• eye movements

Review of medical history

Sometimes, a review of your medical history can tell them some of the most important things they need to know. For example, it would be helpful for you and a loved one to both report the symptoms you’ve experienced. It’s helpful to have a loved one give their account of your symptoms to give the doctor more context. Doctors need all the details possible to ensure an accurate diagnosis.

Blood tests

Blood testing rules out and looks for definitive signs of disease, according to the NIA. Your doctor may want to check your protein levels to see if they are atypical. They may also test for other conditions that cause similar symptoms to rule out all possibilities.

Neurological testing

The neurologist will run various tests to check your physical functioning, reflexes, and thinking. They may also conduct a:

• memory test
• language skills test
• math skills test
• balance check
• sensory test

Any variations here can be a sign of dementia.

Brain scans

Imaging tests might include MRI, CT, or positron emission tomography (PET) scans. They can identify any changes to the structure of your brain and its function.

These tests also help the physicians rule out other neurological diseases that may cause similar symptoms, such as stroke or cancer.

Sleep test

Your doctor may want to perform a sleep test to look at your brain function. As they monitor your sleep, they look for signs of REM sleep behavior disorder.

Autonomic function testing

Your autonomic nervous system is the part of your brain and nerves that controls how you move or react without thinking. It controls:

• breathing
• blood pressure levels
• heartbeat
• digestion of food
• regulation of body temperature

Testing will help look for problems in its functioning caused by LBD.

Stages of Lewy Body Dementia

Lewy body dementia can be distinguished by early, middle, and late stages:

Early Stages

In general, the earlier stages of Lewy body dementia may involve hallucinations or other distortions of reality such as delusions, restlessness, acting out dreams during sleep (called REM sleep disorder), and some movement difficulties.3

Some people may appear to “freeze” or get stuck as they move about. Others may develop urinary urgency and incontinence. Unlike Alzheimer’s disease, memory is usually still fairly intact in the early stages. But confusion and some mild cognitive changes may be present.

Middle Stages

As Lewy body dementia progresses, symptoms develop that more strongly resemble Parkinson’s disease. These symptoms include falls, increased problems with motor functions, difficulty with speech, swallowing problems, and greater paranoia and delusions.

Cognition also continues to decline, with shorter attention and significant periods of confusion occurring.3

Later Stages

In the later stages of Lewy body dementia, extreme muscle rigidity and sensitivity to touch develops.4 People need assistance with almost all activities of daily living. Speech is often very difficult and maybe whispered. Some people stop talking altogether.

Lewy body dementia typically causes the individual to become very susceptible to pneumonia and other infections because of weakness.

Treatment for Lewy body dementia

There’s no cure for Lewy body dementia but many of the symptoms can improve with targeted treatments.

Medications

• Cholinesterase inhibitors. These Alzheimer’s disease medications, such as rivastigmine (Exelon), donepezil (Aricept) and galantamine (Razadyne), work by increasing the levels of chemical messengers in the brain (neurotransmitters) believed to be important for memory, thought and judgment. This can help improve alertness and cognition and might reduce hallucinations and other behavioral problems.

Possible side effects include gastrointestinal upset, muscle cramps and frequent urination. It can also increase the risk of certain cardiac arrhythmias.

In some people with moderate or severe dementia, an N-methyl-d-aspartate (NMDA) receptor antagonist called memantine (Namenda) might be added to the cholinesterase inhibitor.

• Parkinson’s disease medications. These medications, such as carbidopa-levodopa (Sinemet, Rytary, Duopa) can help reduce parkinsonian signs and symptoms, such as rigid muscles and slow movement. However, these medications can also increase confusion, hallucinations and delusions.
• Medications to treat other symptoms. Your doctor might prescribe medications to treat other signs and symptoms associated with Lewy body dementia, such as sleep or movement problems.

Certain medications can worsen memory. Try to avoid over-the-counter sleep aids that contain diphenhydramine (Advil PM, Aleve PM) and medications used to treat urinary urgency such as oxybutynin (Ditropan XL).

Also limit sedatives and sleeping tablets, and talk to your doctor about whether any of the drugs you take might make your memory worse.

Antipsychotic drugs can cause severe confusion, severe Parkinsonism, sedation and sometimes death. Very rarely, certain second-generation antipsychotics, such as quetiapine (Seroquel) or clozapine (Clozaril, Versacloz) might be prescribed for a short time at a low dose but only if the benefits outweigh the risks.

Therapies

Because antipsychotic drugs can worsen Lewy body dementia symptoms, it might be helpful to first try nondrug approaches, such as:

• Tolerating the behavior. Some people with Lewy body dementia aren’t distressed by the hallucinations. In these cases, the side effects of medication might be worse than the hallucinations themselves.
• Modifying the environment. Reducing clutter and noise can make it easier for someone with dementia to function. Caregivers’ responses sometimes worsen behavior. Avoid correcting and quizzing a person with dementia. Offer reassurance and validation of his or her concerns.
• Creating daily routines and keeping tasks simple. Break tasks into easier steps and focus on successes, not failures. Structure and routine during the day can be less confusing.

Lifestyle and home remedies

Symptoms and progression are different for everyone with Lewy body dementia. Caregivers and care partners may need to adapt the following tips to individual situations:

• Speak clearly and simply. Maintain eye contact and speak slowly, in simple sentences, and don’t rush the response. Present only one idea or instruction at a time. Use gestures and cues, such as pointing to objects.
• Encourage exercise. Benefits of exercise include improvements in physical function, behavior and depression. Some research shows exercise might slow cognitive decline in people with dementia.
• Provide mind stimulation. Participating in games, crossword puzzles and other activities that involve thinking skills might help slow mental decline in people with dementia. Encourage artistic and creative activities, such as painting, singing or making music.
• Create opportunities for social activity. Talk to friends. Participate in religious services.
• Establish bedtime rituals. Behavior issues can worsen at night. Create calming bedtime rituals without the distraction of television, meal cleanup and active family members. Leave night lights on to prevent disorientation.

Limiting caffeine during the day, discouraging daytime napping and offering opportunities for daytime exercise might help prevent nighttime restlessness.

Alternative medicine

Frustration and anxiety can worsen dementia symptoms. To promote relaxation, consider:

• Music therapy, which involves listening to soothing music
• Pet therapy, which involves the use of animals to improve moods and behaviors in people with dementia
• Aromatherapy, which uses fragrant plant oils
• Massage therapy

Coping and support

People with Lewy body dementia often have a mixture of emotions, such as confusion, frustration, anger, fear, uncertainty, grief and depression. Offer support by listening, reassuring the person that he or she still can enjoy life, being positive, and doing your best to help the person retain dignity and self-respect.

If you’re a caregiver or care partner for someone with Lewy body dementia, watch the person closely to make sure he or she doesn’t fall, lose consciousness or react negatively to medications. Provide reassurance during times of confusion, delusions or hallucinations.

Looking after yourself

Caring for a person with Lewy body dementia can be exhausting physically and emotionally. You may have anger, guilt, frustration, discouragement, worry, grief or social isolation. Help prevent caregiver burnout by:

• Asking friends or other family members for help when you need it. Consider in-home health services to help you care for the person with Lewy body dementia.
• Exercising regularly and eating a healthy diet.
• Learning about the disease. Ask questions of doctors, social workers and others on the care team.
• Joining a support group.

Many people with Lewy body dementia and their families can benefit from counseling or local support groups. Contact your local agencies on health or aging to get connected with support groups, doctors, resources, referrals, home care agencies, supervised living facilities, a telephone help line and educational seminars.

Is there any way to prevent Lewy body dementia?

There’s no proven way to prevent the onset of LBD or any form of dementia, but there are certain lifestyle habits you can adopt to boost your brain health for as long as possible

These include decreasing/managing stress as much as possible, following a regular sleep routine, maintaining a healthy diet, exercising when possible, staying socially and intellectually active, and managing overall health.