Lewy Body Dementia: Everything you need to know

Have you heard of Lewy body dementia? Probably not. I was unaware of this neurological disorder myself until a doctor said those life-changing words to my grandfather. They say it’s the worst of Parkinson’s and Alzheimer’s disease. Although it is the most common type of progressive dementia amongst the general population, its symptoms go undiagnosed. Read further for more information on how Lewy body dementia affects the body and mind.

Lewy Body Dementia
Lewy Body Dementia

What is Lewy Body Dementia?

It is a progressive neurological disorder characterized by a decline in memory, irregular motor movements, and changes in cognitive and social skills. It is an umbrella term which includes Parkinson’s disease dementia and dementia with Lewy Bodies.

The defining aspect of it is that it is precipitated by a buildup of alpha-synuclein—a protein that naturally occurs in the brain. Researchers are unclear of its purpose in a healthy nervous system. However, in Lewy body dementia, excess alpha-synuclein forms clusters called Lewy bodies. Lewy bodies interfere with the brain’s neurons causing the nerve cells in the brain to die off. As a result, affected sections of the brain decrease in size.

Physical Symptoms of Lewy Body Dementia

While it is known for its cognitive deficits, Lewy bodies gather in multiple areas of the brain. Lewy bodies in the midbrain and basal ganglia impair movement, and Lewy bodies in the brain stem dysregulate sleep. The resulting damage provokes the physical symptoms of the disorder.

 Autonomic Dysfunction

The autonomic nervous system controls functions of the body that typically occur “automatically” such as heart rate, blood pressure, breathing, and digestion. The autonomic nervous system has two divisions—the sympathetic and parasympathetic—and either division stimulates or inhibits bodily processes based on information from the environment. It is the main regulator of the body’s fight or flight response when there is a perceived danger. Those with this are prone to autonomic dysfunction. A malfunctioning autonomic nervous system is comparable to flipping the “on-off” switch in the body. Due to autonomic dysfunction, these patients can present with a variety of symptoms ranging from one extreme to the other:

  • Temperature dysregulation—Shivering or excessive sweating is indicative of heat or cold intolerance.
  • Irregularities in heart rhythm—tachycardia (fast heart rate), bradycardia (slow heart rate), atrial fibrillation
  • High or low blood pressure—Blood pressure changes frequently occur upon standing, as the autonomic nervous system cannot compensate during postural movements.
  • Fainting or blackout episodes—Also termed syncope and pre-syncope, periods of unconsciousness are typically related to abnormal heart rhythms and drastic fluctuations in blood pressure.
  • Dizziness—Disorientation and dizziness are also symptoms stemming from cardiac irregularities.
  • Delayed or rapid digestion—Autonomic dysfunction can lead to delayed gastric emptying (Gastroparesis) or to dumping syndrome when food digests too quickly. Constipation, diarrhea, urgency, bloating, nausea, vomiting, and indigestion are common.
  • Bladder dysfunction—Frequent nighttime urination (nocturnal polyuria) is the largest bladder complaint. Urinating triggers a painful burning sensation.
  • Impotence—A decrease in sexual function is seen in men with autonomic dysfunction.

Movement Disorders and Motor Symptoms

The movement disorders associated with Lewy body dementia mimic Parkinson’s disease. These include resting tremors of the hands, slow movements while carrying out activities, and ataxia from impaired muscle coordination. At first glance, those with Lewy body dementia lack a facial expression and exhibit a stooped posture that is accompanied by poor balance. The motor symptoms require walking assistance as the condition progresses.

Sleep Disorders

A number of sleep disorders present alongside Lewy Body Dementia. Sleep problems tend to precede cognitive, autonomic, and motor symptoms.

  • Insomnia—Difficulty falling or staying asleep.
  • Restless leg syndromeUncomfortable sensations in the legs while resting that results in the urge to move them.
  • Excessive daytime sleepiness—Intense fatigue and a lack of energy during the day, despite adequate sleep at night.
  • REM sleep disorder—Rapid eye movement sleep disorder is prevalent in Lewy body dementia. REM sleep is the deepest stage of sleep in which dreams occur and the body’s muscles are temporarily paralyzed into relaxation. In REM sleep disorder, paralysis is absent and vivid dreams are reenacted without recollection.

Cognitive Symptoms of Lewy Body Dementia

Like all forms of dementia, it is known for its vast effects on cognition. Cognitive impairments of dementia are the outcome of Lewy bodies in the cerebral cortex—the part of the brain involved in processing, perception, and thought. Lewy bodies also accumulate in the limbic cortex and hippocampus to affect emotions, behavior, and memory.

Memory Loss

Memory loss is not as profound in Lewy body dementia as it is in other forms of dementia because it does not arise until the later stages. Long term memory, the memory process dedicated to storing information for an extended period of time, remains more intact than short-term or recent memories.

Psychosis: Hallucinations and Delusions

Hallucinations describe perceptions of the five senses (i.e. sight, touch, sound, taste, and smell) that seem real, yet are falsely created by the mind. Delusions are false beliefs based on the alteration of reality. Someone who is delusional accepts false beliefs as true regardless of contradictory evidence. Both are considered psychosis.

The beginning symptoms manifest as hallucinations and delusions. A study in Parkinsonism and Related Disorders (2013) found that hallucinations recur early in the diagnosis. Visual hallucinations like seeing animals and people are the most common. For example, hallucinating spiders crawling on the wall, and a delusion that claims “something is out to get me” are each noted in patients.

Depression and Mood Swings

This dementia makes it difficult to manage emotions. Patients are inclined to drastic mood swings that drive erratic behaviors. Depression, periods of feeling consistently sad longer than two weeks, significantly affects the outcomes and complicates relationships with caregivers. Depressive episodes are hallmarked by hopelessness, apathy, and reduced motivation.

As reflected in studies with dementia patients, psychiatric manifestations like depression and mood swings are nearly 20 percent more frequent in Lewy body dementia (Chiu, Wang, Tsai, et al., 2017). Depression and mood swings are due to the disease directly impacting the brain, but also from the emotional repercussions of being ill. It is easy to fall into patterns of frustration, especially when the patient is aware of their declining cognitive skills and memory.

Visuospatial Problems

Visuospatial abilities process spatial information and allow us to mentally manipulate and analyze objects. Using visuospatial skills, we can differentiate ourselves in relation to various objects in the environment. It interferes with visuospatial function. Those with this dementia struggle to identify the details of space and visual form. According to the Lewy body dementia Association, depth perception, object orientation, and directional sense suffers without necessary visuospatial skills. This contributes to symptoms of dizziness, imbalance, illusions, and leaves them susceptible to hallucinations.

Other Losses of Executive Functions

This dementia causes loss in other executive functions:

  • Inattention
  • Confusion
  • Poor Organizing and planning
  • Reasoning
  • Problem-solving
  • Fluctuating alertness
  • Disorganized speech

Dementia with Lewy Bodies VS. Parkinson’s Disease Dementia

Parkinson’s disease is the degradation of dopamine-producing brain cells. It causes motor symptoms lumped under the umbrella term parkinsonism, which include resting tremor, ataxia, and slow rigid movements. As Parkinson’s disease progresses, autonomic dysfunction, sleep disorders, and dementia called Parkinson’s disease dementia arise. It is most related to Parkinson’s disease dementia, as these patients also have Lewy body deposits on the brain. The symptoms are the same amongst both disorders, but the main difference is the order of symptom onset. Physical symptoms precede cognitive decline by a year in Parkinson’s, whereas physical and cognitive symptoms decline simultaneously in Lewy body dementia.

Lewy Body Dementia VS. Alzheimer’s Disease

Alzheimer’s disease is a progressive form of dementia that leads to a decline in cognitive function from the destruction of brain cells. A defining attribute of the disorder is amyloid plaques and neurofibrillary tangles rather than Lewy body deposits in the brain. The symptoms of Alzheimer’s are similar to Lewy body dementia, but the two dementias are separated by the cognitive abilities they affect. Alzheimer’s impedes the processes of forming new memories. Memory loss is considerably more profound in the early stages. It has notably less memory impairment early-on. Instead, Lewy body dementia presents with issues in problem-solving, judgment, planning, and visuospatial perception. Movement disorders, the malfunction of the autonomic nervous system, and REM sleep behavior disorder are not as prevalent in Alzheimer’s as in Lewy body dementia.

Causes of Lewy Body Dementia

Professionals are uncertain of the exact cause of Lewy body dementia. There are a few risk factors linked to the development of the disorder. Males over the age of 60 are diagnosed with it more than females. No lifestyle factors have been confirmed as a cause.

Family history is the greatest risk factor. Those who have a family member with Lewy body dementia or Parkinson’s disease dementia are susceptible. Mutations in the APOE, SNCA, and GBA genes indicate the potential for acquiring Lewy body dementia, but it is not normally a genetic condition.

Diagnosing Lewy Body Dementia

Physicians rely on clinical symptoms and biochemical markers to diagnose Lewy body dementia. Initially, the doctor may test neurological functioning by examining:

  • Reflexes
  • Gait/Walking
  • Muscle tone
  • Strength
  • Balance
  • Senses
  • Eye movements

Clinical Symptoms

To diagnose the clinical symptoms alone, a neuropsychologist performs an evaluation of cognition and executive functions. There must be signs of dementia—a deficit that interferes with daily activities in any of the cognitive and thinking skills: attention, problem-solving and reasoning, visuospatial skills, and memory. However, it is important to remember that memory is not as affected in the early stages of Lewy body dementia.

The doctor will look for at least two of the following symptoms in addition to dementia:

  • Parkinsonism—abnormal movements, muscle tremors, rigidity
  • Visual hallucinations
  • REM Sleep Behavior Disorder
  • Changes in alertness and attention with unpredictable behavior

Biochemical Markers

Even with current technology, the presence of Lewy bodies cannot be visualized in the brain until autopsy after death. Researchers have made associations between autopsy confirmed cases of Lewy body dementia and certain findings on objective medical tests. These biomarkers have advanced the diagnostic methods.

Diagnosis through biochemical markers requires dementia plus one clinical symptom and the below tests:

  • Sleep study—confirming REM Sleep Behavior Disorder
  • SPECT or PET brain scans—a reduction in brain cells that produce dopamine
  • MIBG myocardial scintigraphy—decreased communication of the cardiac nerves

Lewy Body Dementia Treatment

Treating it is best accomplished when the entire medical team cooperates for the good of the patient. Specialties might include neurologists, cardiologists, physical therapists, palliative care doctors, mental health counselors, and speech therapists. With the input of many specialists, a combination of treatments is successful in managing the symptoms of Lewy body dementia. There is no cure.


Medications do not slow the progression of the disorder, but an effective combination of drugs can reduce symptoms. Despite the advantages, those with Lewy body dementia are extremely sensitive to medications. Medical professionals prefer to begin treatment with non-drug options.  

  • Cholinesterase inhibitors—Cholinesterase inhibitors are a class of drugs that prevent the breakdown of the neurotransmitter acetylcholine. It is typically prescribed in Alzheimer’s disease but helps cognition, hallucinations, and behavioral problems in Lewy body dementia.
  • Carbidopa-levodopa—Parkinson’s disease medications like Levodopa are replacements for the neurotransmitter dopamine that is able to pass the blood-brain barrier. In Lewy body dementia, Levodopa targets parkinsonian motor symptoms such as muscle rigidity, tremors, and slow movements, but can worsen hallucinations, delusions, confusion, and other cognitive symptoms.
  • Selective Serotonin Reuptake Inhibitors (SSRIs)—SSRIs are a class of antidepressants which balance mood by stopping the reuptake of serotonin.
  • Melatonin—Melatonin is a hormone that regulates the sleep-wake cycle. It treats sleep disorders.
  • Clonazepam—Low dose clonazepam (Klonopin) is beneficial for comorbid REM sleep behavior disorder.  
Medications Treat Lewy Body Dementia
Medications Treat Lewy Body Dementia


Antipsychotic drugs must be prescribed with caution. They are occasionally given to control behavior when the patient becomes a danger to themselves and others, but they can cause parkinsonism, confusion, and induce hallucinations in Lew Body Dementia. Studies show that antipsychotics “double or triple the rate of mortality in patients who have dementia with Lewy bodies” (Neef, 2006).


CogniFit Brain Training
CogniFit Brain Training: Trains and strengthens essential cognitive abilities in an optimal and professional way.

Miscellaneous therapies have proven essential to the management of Lewy body dementia.

Physical therapy—A physical therapist designs a regimen to improve motor symptoms through exercise, gait training, and increasing strength.
• Occupational therapy—Everyday activities are difficult with Lewy body dementia. Occupational therapy adapts tasks like bathing, eating, showering, and household chores.
• Speech therapy—Speech therapy targets speech projection to overcome communications problems.
Psychotherapy—Psychotherapy is talk therapy that can treat secondary mental disorders (i.e. depression, moods swings).
Cognitive stimulation—Cognitive stimulation is a psychological therapy that consists of activities and exercises to improve the cognitive deficits of dementia. It focuses on memory, attention, problem-solving skills, and language ability.
Support groups—Support groups for patients and caregivers promote mental health. Uniting those with mutual challenges supplies tips and tricks to live with the condition and fosters friendship.


Chiu, P. Y., Wang, C. W., Tsai, C. T., Li, S. H., Lin, C. L., & Lai, T. J. (2017). Depression in dementia with Lewy bodies: A comparison with Alzheimer’s disease. PloS one, 12(6), e0179399. doi:10.1371/journal.pone.0179399

Lewy Body Dementia Association. (2018). Early Visual Hallucinations Greatly Increase Odds of LBD Over Alzheimer’s. Retrieved from https://www.lbda.org/go/early-visual-hallucinations-greatly-increase-odds-lbd-over-alzheimer%E2%80%99s

Mayo Clinic Staff. (2019). Lewy body dementia. Retrieved from https://www.mayoclinic.org/diseases-conditions/lewy-body-dementia/symptoms-causes/syc-20352025

Neef, D. & Walling, A.D. (2006). Dementia with Lewy bodies: an emerging disease. Am Fam Physician, 73(7):1223-1229.

Leave a Reply