Lewy body dementia, also known as dementia with Lewy bodies, is the second most common type of progressive dementia after Alzheimer's disease dementia. 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 may experience visual hallucinations and changes in alertness and attention. Other effects include Parkinson's disease-like signs and symptoms such as rigid muscles, slow movement and tremors.
Lewy body dementia signs and symptoms may include:
- Visual hallucinations. Hallucinations may be one of the first symptoms, and they often recur. They may include seeing shapes, animals or people that aren't there. Sound (auditory), smell (olfactory) or touch (tactile) hallucinations are possible.
- Movement disorders. Signs of Parkinson's disease (parkinsonian signs), such as slowed movement, rigid muscles, tremor or a shuffling walk may occur. This can also result in falls.
- Poor regulation of body functions (autonomic nervous system). Blood pressure, pulse, sweating and the digestive process are regulated by a part of the nervous system that is often affected by Lewy body dementia. This can result in dizziness, falls and bowel issues such as constipation.
- Cognitive problems. You may experience thinking (cognitive) problems similar to those of Alzheimer's disease, such as confusion, poor attention, visual-spatial problems and memory loss.
- Sleep difficulties. You may have rapid eye movement (REM) sleep behavior disorder, which can cause you to physically act out your dreams while you're asleep.
- Fluctuating attention. Episodes of drowsiness, long periods of staring into space, long naps during the day or disorganized speech are possible.
- Depression. You may experience depression sometime during the course of your illness.
- Apathy. You may have loss of motivation.
Lewy body dementia is characterized by the abnormal buildup of proteins into masses known as Lewy bodies. This protein is also associated with Parkinson's disease. People who have Lewy bodies in their brains also have the plaques and tangles associated with Alzheimer's disease.
A few factors seem to increase the risk of developing Lewy body dementia, including:
- Age. People older than 60 are at greater risk.
- Sex. Lewy body dementia affects more men than women.
- Family history. Those who have a family member with Lewy body dementia or Parkinson's disease are at greater risk.
Lewy body dementia is progressive. Signs and symptoms worsen, causing:
- Severe dementia
- Aggressive behavior
- Increased risk of falling and injury
- Worsening of parkinsonian signs and symptoms, such as tremors
- Death, on average about eight years after symptoms start
A diagnosis of Lewy body dementia requires a progressive decline in your ability to think, as well as two of the following:
- Fluctuating alertness and thinking (cognitive) function
- Repeated visual hallucinations
- Parkinsonian symptoms
- REM sleep behavior disorder, in which people act out their dreams during sleep
Autonomic dysfunction, which involves instability in blood pressure and heart rate, poor regulation of body temperature, sweating, and related symptoms, supports a Lewy body dementia diagnosis.
No single test can diagnose Lewy body dementia. Instead, doctors diagnose your condition through ruling out other conditions that may cause similar signs and symptoms. Tests may include:
Neurological and physical examination
Your doctor may check for signs of Parkinson's disease, strokes, tumors or other medical conditions that can affect the brain and physical function. The neurological examination may test:
- Muscle tone
- Eye movements
- Sense of touch
Assessment of mental abilities
A short form of this test, which assesses your memory and thinking skills, can be done in less than 10 minutes in your doctor's office. It's not generally useful in distinguishing Lewy body dementia from Alzheimer's disease but can indicate dementia. Longer tests can take several hours, but help identify Lewy body dementia.
Your doctor will compare your test results with those of people of a similar age and education level. This can help distinguish normal from abnormal cognitive aging, and may help diagnose the condition.
These can rule out physical problems that can affect brain function, such as vitamin B-12 deficiency or an underactive thyroid gland.
Your doctor may order an MRI or CT scan to identify a stroke or bleeding and to rule out the possibility of a tumor. While dementias are diagnosed based on the medical history and physical examination, certain features on imaging studies can suggest different types of dementia, such as Alzheimer's or Lewy body dementia.
Most of the time, you won't need more brain scans. If the diagnosis is unclear or the signs and symptoms aren't typical, your doctor may suggest some additional imaging tests, including these that can support a diagnosis of Lewy body dementia:
- Fluorodeoxyglucose PET brain scans, which can assess brain function.
- Single-photon emission computerized tomography (SPECT) or PET imaging, which can determine whether dopamine transporter uptake is reduced in the brain.
Your doctor may order a sleep evaluation to check for REM sleep behavior disorder or an autonomic function test to look for signs of heart rate and blood pressure instability.
Your doctor may also order a heart test called myocardial scintigraphy to check the blood flow to your heart, which can be a sign of Lewy body dementia.
Treatment can be challenging, and there's no cure for Lewy body dementia. Doctors treat the individual symptoms.
Cholinesterase inhibitors. These Alzheimer's disease medications, such as rivastigmine (Exelon), donepezil (Aricept) and galantamine (Razadyne), work by increasing the levels of chemical messengers believed to be important for memory, thought and judgment (neurotransmitters) in the brain. This can help improve alertness and cognition, and may help reduce hallucinations and other behavioral problems.
Possible side effects may include gastrointestinal upset, excessive salivation and tearing, and frequent urination. Donepezil is not approved by the Food and Drug Administration for Lewy body dementia.
In some people with moderate or severe dementia, an N-methyl-d-aspartate (NMDA)-receptor antagonist called memantine (Namenda) may be added to the cholinesterase inhibitor.
- Parkinson's disease medications. These medications, such as carbidopa-levodopa (Sinemet, Rytary, Duopa) may help reduce parkinsonian signs and symptoms, such as rigid muscles and slow movement. However, these medications may also increase confusion, hallucinations and delusions.
- Medications to treat other symptoms. Your doctor may prescribe medications to treat other signs and symptoms associated with Lewy body dementia, such as sleep or movement problems.
If possible, avoid medications with anticholinergic properties, which can worsen cognition, or dopamine agonists, which can cause hallucinations.
First-generation antipsychotic medications, such as haloperidol (Haldol), should not be used to treat Lewy body dementia. They may cause severe confusion, severe parkinsonism, sedation and sometimes even death. Very rarely, certain second-generation antipsychotics may be prescribed for a short time at a low dose but only if the benefits outweigh the risks.
Because antipsychotic drugs can worsen Lewy body dementia symptoms, it might be helpful to first try nondrug approaches, such as:
- Tolerating the behavior. Many times a person with Lewy body dementia isn't distressed by the hallucinations. In these cases, the side effects of medication may be worse than the hallucinations themselves.
- Modifying the environment. Reducing clutter and distracting noise can make it easier for someone with dementia to function.
- Offering soothing responses. A caregiver's response may 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.
Symptoms and progression are different for everyone with Lewy body dementia. Caregivers 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 symptoms. Some research shows exercise may slow cognitive decline in people with dementia.
- Provide mind stimulation. Participating in games, crossword puzzles and other activities that involve using thinking skills may help slow mental decline in people with dementia.
- Establish a nighttime ritual. Behavior issues may 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 may help prevent nighttime restlessness.
Frustration and anxiety can worsen dementia symptoms. These techniques may help promote relaxation:
- Music therapy, which involves listening to soothing music
- Pet therapy, which involves the use of animals to improve moods and behaviors in dementia patients
- Aromatherapy, which uses fragrant plant oils
- Massage therapy
People with Lewy body dementia often experience 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 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
The physical and emotional demands of caregiving can be exhausting. You may experience 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 as much about the disease as you can. 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.
You'll probably first discuss your symptoms with your family doctor, who may refer you to a doctor trained in dementia — usually a doctor trained in brain and nervous system conditions (neurologist) or mental health conditions (psychiatrist).
Because appointments can be brief, and because there's often a lot to talk about, be prepared for your appointment. You may also want to bring along a family member. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
Plan ahead and write lists of important information, including:
- Write a detailed description of all your symptoms.
- Make a list of all medications, vitamins or supplements that you're taking.
- Write down questions to ask your doctor, such as what tests or treatments he or she may recommend.
- Take a family member or friend along. A family member or close friend may tell your doctor about symptoms you may not have noticed.
What to expect from your doctor
Your doctor is likely to ask you and your spouse, partner or close friend a number of questions about:
- Changes in your memory, personality and behavior
- Visual hallucinations
- Medications you're taking
- Your history of stroke, depression, alcohol abuse, head trauma or other neurological disorders