What is Lewy body dementia? Symptoms, Causes, and Treatment


What is Lewy Body Dementia?

Lewy body dementia is a type of dementia clinically similar to Alzheimer’s disease that is also accompanied by symptoms like hallucinations and parkinsonian features such as rigid muscles, slow movement, and tremors. Dementia is a general term for loss of memory and other mental abilities, severe enough to interfere with daily life. It is caused by physical changes in the brain. Lewy body dementia is now considered to be the second most common cause of dementia after Alzheimer’s disease in the elderly. Protein deposits, called Lewy bodies, develop in nerve cells in the brain regions involved in thinking, movement, memory, mood, and behavior (Mayo Clinic Staff, 2019).

There are two types of Lewy body dementia (Lava, 2019):

  • Dementia with Lewy bodies:Often starts with having a hard time moving your body. Within a year, you will have thinking and memory problems, along with behavioral changes. You also experience visual hallucinations (seeing things that aren’t there).
  • Parkinson’s disease dementia:First causes movement problems. Memory problems happen much later in the disease.

Lewy body dementia is characterized by symptoms of progressive decline of mental abilities of sufficient magnitude to interfere with normal social or occupational function. Memory impairment need not be prominent or persistent early in the course of the illness (Sadock, et al., 2017). It affects more than 1 million people in the US. It typically begins at age 50 or older. It affects slightly more men than women (National Institute on Aging, 2108).

Lewy body dementia is a progressive disease, meaning symptoms start slowly and worsen over time. It lasts an average of 5 to 8 years from the time of diagnosis to death, with a range from 2 to 20 years. How quickly symptoms develop and change depends on overall health, age, and severity of symptoms. In the early stages, symptoms can be mild, and people can function fairly normally. As the disease advances, they will require more help due to a decline in thinking and movement abilities. In the later stages of the disease, they often depend entirely on others for assistance and care (National Institute on Aging, 2108).

Some Lewy body dementia symptoms may respond to treatment for some time. Currently, there is no treatment that cures the disease (National Institute on Aging, 2108).

Symptoms of Lewy Body Dementia

The three core symptoms of Lewy body dementia are (Sadock, et al., 2017):

  1. Fluctuating cognitive ability, attention, and alertness:
    • Fluctuation may occur rapidly in minutes to hours or slower with weekly or monthly variation in the level of attention or alertness.
    • Trouble making decisions, judging distances, multitasking, planning, organizing, or remembering
    • Daytime drowsiness and lethargy with lengthy naps
    • Periods of confusion upon awakening
    • Reduced awareness of the environment – staring into space
    • “Switch off” or go blank at times
    • Episodes of disorganized speech
    • Periods of marked lucidity during which patients appear to spontaneously remit.
  2. Visual Hallucinations: Hallucinations may be one of the first symptoms, and they often recur. They occur in up to 80 percent of people with Lewy body dementia. They may include:
    • Seeing animals or people that aren’t there, intruding into the home
    • Seeing inanimate objects or writing on the walls and ceiling
    • Emotional responses to these experiences can range from indifference to amusement to fear.
    • Nonvisual hallucinations, such as hearing or smelling things that are not present, are less common but may also occur.
  3. Spontaneous motor features of parkinsonism: Signs of Parkinson’s disease (parkinsonian signs), such as:
    • Slowed movement
    • Rigid muscles
    • Stooped posture
    • Mask-like facies
    • Tremor or shaking, usually at rest
    • Shuffling walk
    • Difficulty swallowing
    • Weak voice

Other symptoms suggestive of a diagnosis of Lewy body dementia are (Sadock, et al., 2017) (Alzheimer’s Association, n.d.):

  1. Sleep behavior disorder:
    • Vivid and often frightening dreams
    • Could physically “act out dreams” while still asleep
    • Vocalizations
    • Thrashing about
    • Arising from bed
    • Often moving about violently
    • Do not recall their dreams or these episodes
    • Sleeping a lot during the daytime (as much as 2 hours every day)
    • Trouble falling or staying asleep
  2. Severe sensitivity to antipsychotics:
    • Present in about half of the patients.
    • Acute onset or exacerbation of parkinsonism and impaired consciousness with even a low dose of a first- or second-generation antipsychotic drug.
    • Antipsychotics should generally be avoided in the treatment of psychotic symptoms in this disease.
  3. Memory loss that may be significant but less prominent than in Alzheimer’s.

Symptoms that are supportive of a diagnosis of Lewy body dementia, but not having specificity, are (Lava, 2019) (Sadock, et al., 2017) (National Institute on Aging, 2108):

  1. Repeated falls.
  2. Temporary unexplained loss of consciousness.
  3. Other symptoms due to autonomic nervous system disturbance: They can include:
    • Changes in body temperature
    • Problems with blood pressure
    • Dizziness
    • Sensitivity to heat and cold
    • Sexual dysfunction
    • Urinary incontinence
    • Constipation
    • A poor sense of smell
  1. Delusions (strongly held false beliefs or opinions not based on evidence): Delusions of persecution and theft, phantom boarders, television characters in the room, spousal infidelity, and Capgras syndrome, in which the person believes a relative or friend has been replaced by an imposter.
  2. Depression: Sometime during the course of your illness.
  3. Apathy: Loss of motivation. A lack of interest in normal daily activities or events; less social interaction.
  4. Anxiety: Intense apprehension, uncertainty, or fear about a future event or situation. A person may ask the same questions over and over or be angry or fearful when a loved one is not present.
  5. The urge to move your legs when you’re at rest called restless legs syndrome.

Causes of Lewy Body Dementia

The precise cause is not known. But, we know that an accumulation of Lewy bodies is associated with a loss of certain neurons in the brain that produce two important neurotransmitters (chemicals messengers in the brain): (1) Acetylcholine, which is important for memory and learning, and (2) Dopamine, which plays an important role in behavior, cognition, movement, motivation, sleep, and mood (National Institute on Aging, 2108).

The risk factors for Lewy body dementia are (National Institute on Aging, 2108):

  • Age: People older than 50 are at greater risk.
  • Diseases and health conditions: Those with Parkinson’s disease or REM sleep behavior disorder are linked to a higher risk.
  • Genetics: Those who have a family member with Lewy body dementia or Parkinson’s disease are at greater risk. Variants in three genes—APOE, SNCA,and GBA—have been associated with an increased risk. At this time, no genetic test can accurately predict whether someone will develop Lewy body dementia.

Diagnosis of Lewy Body Dementia

Diagnosis is based on the symptoms outlined above and the following examinations and tests (Mayo Clinic Staff, 2019):

  • Neurological and physical examination: You will be checked 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 Reflexes, Strength, Walking, Muscle tone, Eye movements, Balance, and 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. These test results will be compared 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.
  • Blood tests: These can rule out physical problems that can affect brain function, such as vitamin B-12 deficiency or an underactive thyroid gland.
  • Brain scans: 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 medical history and physical examination, certain features on imaging studies can suggest different types of dementia, such as Alzheimer’s or Lewy body dementia. Additional imaging tests could be done, including: (1) FDG PET brain scans, which can assess brain function, and (2) Single-photon emission computerized tomography (SPECT) or PET imaging, which can determine whether dopamine transporter uptake is reduced in the brain.
  • Other tests: Sleep evaluation could be done to check for REM sleep behavior disorder. An autonomic function test can be done to look for signs of heart rate and blood pressure instability. Myocardial scintigraphy could be done to check the blood flow to your heart, which can be a sign of Lewy body dementia.

Treatment of Lewy Body Dementia (Sadock, et al., 2017) (Mayo Clinic Staff, 2019)

Pharmacological Treatment

  • Cholinesterase Inhibitors. The cholinesterase inhibitors are the mainstay of treatment for the cognitive impairment. Improvements in cognition, behavior, and global functioning, as well as reductions in caregiver burden, have been shown with donepezil (Aricept). Significant improvements in apathy, anxiety, delusions, hallucinations, and cognitive functioning have occurred with rivastigmine (Exelon). Another drug that shows promise is galantamine (Razadyne). These drugs work by increasing the levels of neurotransmitters believed to be important for memory, thought and judgment. 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.
  • Memantine. It can improve the quality of life and improve global clinical status. However, some side effects have been reported, such as worsening hallucinations and delusions.
  • Antiparkinsonian Medications. Antiparkinsonian medications including carbidopa-levodopa (Sinemet, Rytary, Duopa) may help reduce parkinsonian signs and symptoms, such as rigid muscles and slow movement. Initial doses should be small, with gradual increases since these medications may also increase confusion, hallucinations, and delusions.
  • Antipsychotics. First-generation antipsychotics are generally avoided. Very rarely, second-generation antipsychotics may be prescribed for a short time at a low dose but only if the benefits outweigh the risks. A decrease in positive symptoms of psychosis without worsening of parkinsonism or cognition was seen with olanzapine. A clinically significant reduction in symptoms was seen with quetiapine in about half the patients, but several had to discontinue treatment due to drowsiness and dizziness upon standing (orthostatic hypotension). There may be some clinical value in using clozapine for the treatment of psychotic symptoms.
  • Antidepressants. SSRIs and SNRIs are preferred.
  • Benzodiazepines. Clonazepam may have benefit for the treatment of REM sleep behavior disorder, but must be used cautiously in the elderly.
  • Anticholinergic medications are generally not recommended, because of the associated cognitive side effects.

 Nonpharmacological Treatment

  • Modify the environment. Reduce clutter and noise so that the person with dementia finds it easier to function.
  • Offer soothing responses. Do not correct or quiz a person with dementia. Reassure and validate his or her concerns.
  • Create daily routines and keep tasks simple. To lessen confusion, structure the day with a predictable routine. Simplify tasks by diving them up into simpler steps. Focus on successes, not failures.
  • Lifestyle and home remedies: Caregivers need to tailor these to individual situations:
    • Speak clearly, slowly, and simply. Speak slowly in simple sentences maintaining eye contact. Do not give more than one idea or instruction at a time. Whenever necessary, use gestures and point to objects.
    • Encourage exercise. Exercise improves physical function, behavior and depression symptoms. It may also slow cognitive decline in people with dementia.
    • Provide mind stimulation. Participating in activities that involve thinking skills, such as games and crossword puzzles, may help slow mental decline in people with dementia.
    • Promote peaceful sleep. Limit caffeine during the day, discourage daytime napping and offer opportunities for daytime exercise to help prevent nighttime restlessness. Create calming bedtime rituals by avoiding disturbances from television, cleanup, and other activities by family members. Prevent disorientation by leaving night lights on.
  • Alternative medicine: To avoid frustration and anxiety, which can worsen dementia symptoms, use these techniques to promote relaxation:
    • Listening to soothing music
    • Using animals to improve moods and behaviors
    • Using fragrant plant oils
    • Giving massage


Alzheimer’s Association, n.d. Lewy Body Dementia. [Online]
Available at: https://www.alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia/lewy-body-dementia
[Accessed 16 Sep 2019].

Lava, N., 2019. What Is Lewy Body Dementia?. [Online]
Available at: https://www.webmd.com/alzheimers/guide/dementia-lewy-bodies#1
[Accessed 16 Sep 2019].

Mayo Clinic Staff, 2019. Lewy body dementia. [Online]
Available at: https://www.mayoclinic.org/diseases-conditions/lewy-body-dementia/symptoms-causes/syc-20352025
[Accessed 16 Sep 2019].

National Institute on Aging, 2108. What Is Lewy Body Dementia?. [Online]
Available at: https://www.nia.nih.gov/health/what-lewy-body-dementia
[Accessed 16 Sep 2019].

Sadock, B. J., Sadock, V. A. & Ruiz, P., 2017. Kaplan and Sadock’s Comprehensive Textbook of Psychiatry. 10th ed. Philadelphia: Wolters Kluwer.


What is Lewy body dementia?
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What is Lewy body dementia?
Lewy body dementia is a type of dementia with symptoms like hallucinations and parkinsonian features such as rigid muscles, slow movement, and tremors.
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