General overview of Lewy body dementia, a disease that causes decline in mental abilities and visual hallucinations.
Lewy Body Dementia (LBD): Also known as Dementia with Lewy bodies (DLB), diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type, is defined as a type of dementia closely associated with Parkinson's disease. LBD's primary feature is cognitive decline, which can lead to hallucinations, as well as varied attention and alertness.
Lewy body dementia is the second most common type of progressive dementia after Alzheimer's disease and causes a progressive decline in a person's mental abilities. It might also cause visual hallucinations, which usually take the form of people, objects, or animals that are not there. The hallucinations may lead to behavior such as having a conversations with a deceased loved one, for example.
Another indicator of Lewy body dementia may be significant fluctuations in both attention and alertness, which might include daytime drowsiness or periods of staring into space. As with Parkinson's disease, Lewy body dementia may result in slowed movement, rigid muscles and tremors. In Lewy body dementia, protein deposits called, 'Lewy bodies,' develop in nerve cells in regions of a person's brain involved with thinking, movement and memory.
Lewy body dementia signs and symptoms include visual hallucinations. The affected person might see visual hallucinations such as shapes, colors, people or animals that are not there. The hallucinations might be one of the first symptoms of Lewy body dementia. Some people also may experience auditory, olfactory, or tactile hallucinations. Additional symptoms include the following.
A person with Lewy body dementia might experience depression during the course of their illness.
An affected person may have frequent episodes of drowsiness, long periods of staring into space, long naps during the day, or disorganized speech.
A person might experience symptoms similar to those of Parkinson's disease such as rigid muscles, slowed movement, a shuffling walk, or tremors.
A person with Lewy body dementia might have a sleep disorder called, 'rapid eye movement (REM) sleep behavior disorder,' that may cause them to physically act out their dreams as they are sleeping.
An affected person might experience cognitive issues similar to ones experience by people with Alzheimer's disease such as confusion, a reduction in the person's attention span, as well as eventual memory loss.
Pulse, blood pressure, sweating and digestive process are regulated by a part of the nervous system that is often affected by Lewy body dementia, something that may result in dizziness, falls and bowel issues.
The cause of Lewy body dementia remains an unknown, although the disorder might be related to Parkinson's disease or Alzheimer's. Lewy bodies contain a protein associated with Parkinson's disease. Lewy bodies are often times present in the brains of people with Parkinson's disease, Alzheimer's disease and other forms of dementia. People who have Lewy bodies in their brains also have plaques and tangles associated with Alzheimer's disease.
While the cause of Lewy body dementia is not clear, some different factors seem to increase a person's risk of developing the disease. The risk factors include being male, being over the age of sixty, as well as having a family member with Lewy body dementia. Lewy body dementia is progressive, the signs and symptoms worsen and cause severe dementia and death - on average around eight years after onset of the condition.
In order for a person to be diagnosed with Lewy body dementia, they must have experienced a progressive decline in their ability to think, as well as two of the following:
In addition, one or more of the following features are considered to be supportive of a diagnosis of Lewy body dementia:
No one test can diagnose Lewy body dementia.
Instead, doctors diagnose the condition by ruling out other conditions that might cause similar signs and symptoms. There are a number of tests for the condition, which are spelled out below.
Simple blood tests may rule out physical issues that can affect a person's brain function, such as vitamin B-12 deficiency, or an under-active thyroid gland.
A doctor might order an MRI, CT, or PET scan to check for evidence of Alzheimer's disease, stroke or bleeding, as well as to rule out the possibility of a tumor.
A doctor may order a sleep evaluation to assess for REM sleep behavior disorder, or an autonomic function test to look for signs of heart rate and blood pressure instability.
As a portion of the person's physical examination, a doctor may also check for signs of Parkinson's disease, tumors, strokes or other medical conditions that may impair the person's brain function, as well as physical function. The neurological examination may test the person's balance, reflexes, sense of touch and eye movements.
If a person's confusion comes and goes, a doctor may suggest an EEG. The test might help to determine if the person's symptoms may be caused by seizures or Creutzfeldt-Jakob disease, a rare and degenerative brain disorder leading to dementia. The painless test records the electrical activity of a person's brain through wires attached to their scalp.
A short form of this type of test, which assesses a person's thinking and memory skills, may be performed in less than ten minutes in a doctor's office, yet is generally not useful in distinguishing Lewy body dementia from Alzheimer's disease. Longer forms of neuropsychological testing may take several hours, although these tests help to identify the condition. The person's results are then compared to those of people of similar age and education level. The testing may help to distinguish average from non-average cognitive aging and might help identify patterns of cognitive functions that provide clues to the underlying condition.
Treating Lewy body dementia can be very challenging. There is no cure for it. Instead, doctors treat the individual symptoms an affected person is experiencing. Medications are available to help and include the following.
The medications, such as carbidopa-levodopa, may help to reduce parkinsonian symptoms such as slow movement and rigid muscles in some people with Lewy body dementia. The medications; however, might also cause increased hallucinations, confusion and delusions.
The medications, such as quetiapine, olanzapine and others might somewhat improve delusions and hallucinations. Some people with Lewy body dementia; however, have a dangerous sensitivity to some of these medications. Reactions, which are at times irreversible, may include severe parkinsonian symptoms and confusion.
Cholinesterase inhibitors are Alzheimer's disease medications such as rivastigmine and work by increasing the levels of chemical messengers believed to be important for thought, judgment and memory in the brain. The medications may help to improve the person's cognition and alertness and may help reduce hallucinations and additional behavioral issues. Potential side-effects may include excessive salivation and tearing, gastrointestinal upset and frequent urination.
A doctor may prescribe medications to treat other symptoms associated with Lewy body dementia, such as movement or sleep issues.
Due to the fact that antipsychotic medications may worsen Lewy body dementia symptoms, it may be helpful to initially try non-medication approaches. These approaches include the following.
Break tasks into easier steps and focus on successes, not failures. Structure and routine during the day also helps to reduce confusion in people who experience forms of dementia.
A caregiver's response to a behavior can make the behavior worse! It is best to avoid correcting and quizzing a person with dementia. Reassuring the person and validating their concerns may help to resolve a number of situations.
Many times, a person with Lewy body dementia is not distressed by the hallucinations and even recognizes them as such. In these instances, the side-effects of medication might be worse than experiencing hallucinations.
Reducing clutter and distracting noise may make it easier for a person with dementia to focus and function. It might also reduce the risk that a person with Lew body dementia will misperceive objects in their environment and produce behaviors similar to hallucinations.
LBD affects more than 1 million individuals in the United States.
An estimated 60 to 75% of diagnosed dementias are of the Alzheimer's and mixed (Alzheimer's and vascular dementia) type, 10 to 15% are Lewy body type, with the remaining types being of an entire spectrum of dementias, including frontotemporal lobar degeneration (Picks Disease), alcoholic dementia, pure vascular dementia, etc.
LBD is slightly more prevalent in males than females.