What is Lewy Body Dementia?
Lewy Body Dementia (LBD) is a type of brain disorder that gets worse over time and includes two related conditions: dementia with Lewy bodies and Parkinson’s disease dementia. It’s marked by memory loss, false beliefs, and symptoms similar to Parkinson’s disease. Not everyone with LBD will have the same symptoms, and these symptoms can change over time. To determine if someone has LBD, doctors need to do a thorough examination as it shares many similarities with other forms of dementia. It’s the third most common kind of dementia, coming after Alzheimer’s disease and vascular dementia.
LBD is characterized by the build-up of Lewy bodies in the brain. These are clumps of protein within the brain cells, made up of “alpha-synuclein” and “ubiquitin” proteins.
There’s ongoing debate about how LBD relates to Parkinson’s disease. The most recent guidelines suggest using a 12-month rule to tell the difference between LBD from Parkinson’s disease with dementia. Put simply, if cognitive problems (like memory loss and difficulty thinking) began a year or more after Parkinson’s symptoms, it is more likely to be diagnosed as Parkinson’s disease with dementia. If cognitive problems started earlier, it’s typically considered Lewy Body Dementia. In many LBD cases, dementia appears before motor symptoms, especially periods of reduced alertness and false visual experiences (hallucinations).
What Causes Lewy Body Dementia?
We still don’t know exactly what causes Lewy body dementia (LBD). But it’s likely that a combination of genetics, environmental factors, and changes associated with aging are involved. However, more research is needed to understand these factors better.
Risk Factors and Frequency for Lewy Body Dementia
Lewy body dementia (LBD) is a condition that often goes undetected because it’s not very well understood and its symptoms can be similar to more well-known conditions like Parkinson’s disease and Alzheimer’s disease. Despite being under-diagnosed, it makes up roughly 20% to 30% of all cases of dementia.
LBD is more commonly found in men and the chances of having it increase as people get older. People of Asian, African, and European descent may be more likely to have it. Additionally, having a family history of LBD or Parkinson’s disease puts one at a higher risk of developing LBD.
Signs and Symptoms of Lewy Body Dementia
Lewy Body Dementia (LBD) can show a wide range of symptoms in patients and these may start at different times. The main symptoms usually include worsening dementia (meaning the patient’s attention and decision-making abilities could be impacted more severely than their memory), changes in cognitive function (where a patient’s ability to pay attention or stay awake might waver), recurring and detailed visual hallucinations, unfounded beliefs, fainting, and signs of Parkinson’s disease such as muscle stiffness, tremors, and slowed movements.
There are also less frequently seen symptoms which include: a disorder that causes people to act out their dreams while they sleep, dysfunction of the body’s automatic, or “autonomic” processes, sudden falls for no apparent reason, depression, and a negative reaction to medication typically used to treat psychosis.
To diagnose LBD, doctors look at the following criteria:
- For probable LBD diagnosis: Progressive dementia coupled with two of the main symptoms.
- For possible LBD diagnosis: Progressive dementia coupled with one of the main symptoms.
We categorize this condition into two types:
- Dementia with Lewy Bodies: This is when dementia symptoms appear either first or within a year of movement disorder symptoms.
- Parkinson Disease Dementia: This is when a patient already diagnosed with Parkinson’s disease subsequently starts showing dementia symptoms at least a year after their original diagnosis.
A test called the Mini-Mental Status Exam can demonstrate cognitive impairment in LBD patients. However, it’s worth noting that because symptoms can fluctuate, the results might not be consistent. Although patients could show signs of Parkinson’s disease, these are often mild. One particularly characteristic symptom of LBD is orthostatic hypotension, where a person’s blood pressure falls significantly when they stand up. This is often seen early on in the disease. Other symptoms that should also be screened for include excessive sleepiness, loss of smell, lack of interest or enthusiasm, and feelings of unease or worry.
Testing for Lewy Body Dementia
Lewy Body Dementia (LBD) is a tricky condition to diagnose because there’s no specific test that can confirm it. Usually, doctors will perform a variety of checks to narrow down the possibilities, including:
* Taking a detailed medical history and carrying out a thorough physical examination
* Assessing your mental function
* Doing blood tests. These might include checking your levels of vitamin B12, running a chemistry panel to assess your general health, checking your thyroid profile to rule out related conditions, and screening for conditions like syphilis and HIV, which can cause dementia-like symptoms.
* Performing different imaging studies, like a CT scan, an MRI scan, a SPECT scan, or a PET scan of the brain.
However, unlike the other tests, examining cerebrospinal fluid (the fluid found in the brain and spinal cord) doesn’t usually help diagnose LBD. Similarly, imaging studies aren’t always that helpful, as the changes seen in the brain in LBD patients often look very similar to those seen in patients with vascular dementia, another common type of dementia.
To help with diagnosis, there’s a special checklist of 10 questions called the Lewy body composite risk score. This score helps to assess if patients have LBD by asking about motor symptoms (symptoms that affect movement and coordination), balance, stiffness, and non-motor symptoms.
Despite all these checks and assessments, it’s worth noting that the only definitive way to diagnose LBD is with a postmortem biopsy or autopsy. That’s because the unique features of LBD that allow for a certain diagnosis can only be seen under a microscope after death.
Treatment Options for Lewy Body Dementia
Lewy Body Dementia (LBD) can be managed through a variety of medications. For example, cholinesterase inhibitors are often used to treat cognitive symptoms. These were originally created for Alzheimer’s disease, but they may be more effective for people with LBD. Such medications include rivastigmine, galantamine, and donepezil.
For the movement symptoms associated with the disorder, medications like Carbidopa-Levodopa can be used. However, it’s important to note that these drugs can sometimes cause significant side effects such as delusions, hallucinations, and confusion. Therefore, healthcare providers need to be cautious with this kind of treatment and usually start with low doses.
In situations where hallucinations are causing major distress and aren’t responding to the standard cholinesterase inhibitors, atypical antipsychotics might be used. These include pimavanserin, clozapine, quetiapine, and aripiprazole. However, again, they should be used with caution due to the possible development of neuroleptic sensitivity in LBD patients.
Other medicinal treatments for LBD include Clonazepam/melatonin for a sleep disorder known as REM sleep behavior disorder, and SSRIs, a type of antidepressant, as depression is common in patients with LBD. Another medication called Memantine, which has been studied in clinical trials, might be beneficial for patients in the early stages of LBD.
Aside from drugs, supporting and educating patients and their caregivers about the symptoms and management of the disease is critical. This understanding can help caregivers better handle day-to-day challenges, sometimes even involving home modifications to cater to the needs of the patient.
There are also multiple therapies available that can help improve the patient’s quality of life. These include physiotherapy, occupational therapy, speech therapy and psychotherapy both for the individual and the family. Being part of support groups and keeping up regular exercise are also beneficial for the patient’s overall wellbeing.
What else can Lewy Body Dementia be?
It’s critically important to distinguish Lewy body dementia (LBD) from conditions that have similar symptoms. This is because LBD can respond better to certain medications if they’re used early in the progression of the disease.
The conditions which may appear similar to LBD include:
- Parkinson’s disease
- Alzheimer’s disease
- Frontotemporal dementia
- Prion-related diseases
What to expect with Lewy Body Dementia
The outlook for those diagnosed with Lewy Body Dementia (LBD) can range from fair to poor. Many complications can occur, which include problems such as falling down, inability to move, heart issues, side effects from medication, pneumonia, difficulty swallowing, and depression which can lead to suicide. On average, a person’s lifespan is about five to eight years after being diagnosed with LBD.
This poor outcome can also be attributed to a lack of understanding about LBD among doctors and the public, often resulting in delayed diagnosis. Since it’s difficult to differentiate LBD from other similar conditions, it takes more time to start the appropriate treatment. Hence, it’s important for health professionals to raise awareness about LBD and to develop better ways to diagnose it early.