Lewy Body Dementia: Causes, Symptoms and Treatments
About 4 to 16 percent of dementia cases are attributed to Lewy body dementia (LBD), which is also known as dementia with Lewy bodies (DLB). Roughly 1.4 million Americans are thought to have Lewy body dementia, often in conjunction with Parkinson’s disease.
What is Lewy Body Dementia?
The main factor in LBD, as in Parkinson’s, is the presence of Lewy bodies, or malformed alpha-synuclein protein deposits in nerve cells. The malformations happen as a consequence of protein misfolding. When cells need a particular protein component to perform a vital task, the component assembles within the cell from a collection of amino acids. If it doesn’t form the proper shape, it is considered misfolded, and these misfolded proteins can aggregate to form Lewy bodies.
Lewy bodies are named after their discoverer, Friedrich Heinrich Lewy, a German-born neurologist who immigrated to America shortly before WWII.
The difference between Parkinson’s disease and Lewy body dementia is the location in the brain where Lewy bodies first develop to the point of causing symptoms. In LBD, they mostly concentrate in the cerebral cortex (the outer layer of the brain). In Parkinson’s, they develop mainly in the substantia nigra (a mid-brain structure with a high concentration of dopamine neurons).
Prior to the 1990s, dementia with Lewy bodies was considered rare. After laboratory techniques improved in the detection of Lewy bodies, however, it’s become clear that LBD is at the root of many dementia cases. Because the symptoms overlap with those in Alzheimer’s Disease (AD), patients often receive a wrong diagnosis at first.
The distinction, however, lies in the types of abnormal structures that form in the brain. With AD, dementia occurs as a result of plaques (deposits of beta-amyloid protein fragments between nerve cells) and tangles (deposits of tau protein fibers within cells). With LBD, when enough abnormal alpha-synuclein proteins accumulate in the nerve cells, normal cell functioning fails, they die, and Lewy body dementia develops as a result.
Symptoms of Lewy Body Dementia
Although Lewy body dementia symptoms can also be attributed to Alzheimer’s disease (AD) and Parkinson’s disease dementia (PDD), it is considered a distinct form of dementia. Symptoms include:
- Disruptions in thinking and reasoning
- Loss of memory
- Variable periods of confusion and alertness depending on time of day or from day to day
- Slowed walking
- Disruptions to REM (rapid eye movement) sleep, a critical part of healthy brain activity and memory consolidation
- Acting out of dreams
- Stiff muscles
- Stooped posture
- Shuffling gait
- Loss of motor control
- Movement disorders
- Delusions and hallucinations
- Disruption in vision or the ability to understand visual information
- Malfunctioning autonomic nervous system (a part of the peripheral nervous system that controls heart rate, blood pressure, breathing, digestion and more)
Because signs of Lewy body dementia can resemble PDD and AD, physicians may consider the order of symptom development before rendering a firm diagnosis.
Stages and Progression of Dementia with Lewy Bodies
LBD usually proceeds along a common progression shared by other dementias. Usually, the first signs of cognitive decline are barely noticeable, and they’re often attributed simply to age or stress. By the fourth stage, symptoms become more pronounced. This is the time when most people seek medical help.
Lewy Body Dementia normally proceeds in these stages:
- No discernable signs. The Lewy bodies have yet to create much impact.
- Very mild impairment in cognitive function such as forgetting names and misplacing objects. Because LBD almost universally affects people over the age of 60, it may seem like normal, minor age-related forgetfulness.
- Some memory loss, difficulty concentrating and increased forgetfulness. This is usually when family and friends notice a problem.
- More frequent and severe disruptions in memory, difficulty performing familiar daily tasks, trouble remembering how to drive and navigate. This is the stage where testing can lead to a clinical diagnosis.
- Life-changing cognitive decline with struggles remembering such things as addresses and phone numbers. May be unable to prepare meals or perform basic daily tasks.
- Cognitive decline becomes severe. Often short-term retention fails, and the person can only recall memories of their earlier life. Urinary incontinence becomes a major issue, and the patient will require support. Also, personalities may change. The average time in this stage is 2.5 years.
- Severe cognitive decline, with loss of ability to communicate, possible loss of ability to walk. Total living support and dementia care becomes necessary. This stage lasts anywhere from 1.5 to 2.5 years.
Causes and Risk Factors
As mentioned above, alpha-synuclein protein deposits have been implicated in the development of dementia with Lewy bodies, as well as Parkinson’s disease and dementia. The question remains: Why do they develop at all? Currently, science has yet to definitively answer that question. Several studies point to a genetic cause along with unresolved oxidative stress in the tissues as the cause of LBD.
Many risk factors associated with LBD are the same as AD and PD. However, while it is believed that smoking, alcohol use and a lower level of education play a statistically significant role in developing Alzheimer’s disease and Parkinson’s disease, the analysis of one case-controlled study determined they do not apply to Lewy body dementia. These researchers found more credible risk if the person has a history of:
- Family members with Parkinson’s disease
- Oophorectomy (removal of one or both ovaries) before age 45
- Low caffeine use
Diagnosis and Lewy Body Dementia Treatment
As with other forms of dementia, diagnosing DLB presents challenges. A clinical diagnosis comes from the judgment of the physician when a physical analysis can’t be performed. The only conclusive way to diagnose LBD is by autopsy. So physicians use a battery of test criteria to narrow it down between AD, LBD, PDD and other forms of dementia. Sometimes, an examination of spinal fluid can guide diagnosis.
With Alzheimer’s disease, memory loss features more prominently in the early stages while movement issues tend to develop in LBD before mental degeneration begins. Curiously, hallucinations, delusions, sleep disturbances and the inability to recognize familiar people happen sooner in LBD than AD. Also more common in early LBD is deterioration of the autonomic nervous system, resulting in low blood pressure, urinary incontinence, dizziness and falls.
When attempting to distinguish between PDD, parkinsonism and LBD, discernment is based on the order in which cognitive impairment symptoms appear. Because LBD and PDD can overreact to anti-psychotic medications – unlike AD – trials with those drugs may assist diagnosis, even if accidentally.
Although there is wide variability in symptoms and onset timelines among those presenting with a Parkinson’s-like dementia, the progression of each type tends to follow a similar pattern. In LBD, dementia is one of the first severe symptoms, whereas with Parkinson’s, motor control and movement disorders appear in the beginning. If a person is diagnosed with PD, and dementia appears within a year, the diagnosis may change to LBD. However, if the person is diagnosed with Parkinson’s disease and dementia follows a year or more later, Parkinson’s disease dementia may become the primary clinical determination. Either way, these diseases are so closely related that they simply occupy different places on the DLB disease spectrum.
At present, no treatments have been identified to cure or slow the cellular damage from Lewy bodies. Drugs to manage symptoms may help in the short term, but they must be carefully managed to prevent worsening other symptoms. Anti-anxiety medications and those that help with sleep may temporarily relieve psychological and sleep disturbance issues. However, because there are many different types of these drugs, some may help while others may cause further damage to the patient.
Recent research shows that increasing physical activity along with progressive resistance training (weight lifting to the extent possible) can promote better cognition and perhaps slow the inevitable decline.
Lewy Body Dementia Care Options
Life after a Lewy body dementia diagnosis will never be the same. It’s a time when many questions arise over the best options for supportive living arrangements. At some point, home care will likely become too difficult for the caretaker and physically dangerous to the one with LBD. However, loving, competent care by a team of dementia care specialists can elevate the person and make life rewarding again.
We specialize in memory care services in the Atlanta area. You or your relative will enjoy the support of a team dedicated to your health, wellness and human dignity. With many options available – from assisted living to our feature-rich Valeo™ Signature Program – every stage of Lewy body dementia will be met with kindness, understanding and professional expertise.
We believe that living with LBD can and should be more than simply getting by. It should be exceptional. That’s why we train team members at every level to recognize the areas where they can assist residents. For more information about LBD care at Heritage, get a free copy of our Guide for Finding the Right Memory Care Community.