|Lewy Body Dementia Association, Inc.
|Description of LBD (from Mental Help Net)
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|Author:||robin [ Thu Oct 14, 2010 8:02 pm ]|
|Post subject:||Description of LBD (from Mental Help Net)|
This good description of Lewy Body Dementia, written by two psychologists, is on the Mental Help Net. The description is divided into three sections: overview, symptoms, and diagnosis/treatment. Note that the Mental Help Net website contains advertisements. Mental Help Net supplies content on a variety of topics to various affiliated websites. (I saw a link to one of those affiliated websites posted to one of the LBD-related Yahoo!Groups.)
http://www.mentalhelp.net/poc/view_doc. ... c&id=13151
Lewy Body Dementia
Carrie Hill, Ph.D. and Natalie Reiss, Ph.D.
Updated: Jul 3rd 2008
Although it is not as familiar to the public as Alzheimer's Disease or Vascular Dementia, Lewy Body Dementia (LBD) is one of the second most common types of dementia (along with Vascular Dementia). Even though this type of dementia was first identified in the 1980s, it does not currently appear in the DSM-IV. Therefore, a person with LBD currently receives a DSM diagnosis of "Dementia Due to Lewy Bodies," which fits into the category "Dementia Due to Other General Medical Conditions." Lewy Body Dementia is sometimes referred to as Lewy Body Disease, Diffuse Lewy Body Disease, or Cortical Lewy Body Disease.
Prevalence statistics describing Lewy Body Dementia are somewhat unclear, primarily because Lewy bodies - the hallmark of this disorder - are associated with several different diseases. This makes it difficult to distinguish LBD from other conditions. Keeping this problem in mind, the Lewy Body Dementia Association reports that up to 20% of all dementia cases are from LBD (over 800,000 people in the United States). The disease appears to affect slightly more men than women.
Lewy Body Dementia is characterized by deposits of a misfolded protein called alpha-synuclein inside neurons (the primary cells in the brain and spinal cord). The protein deposits are called "Lewy bodies" after Friederich H. Lewy, the researcher who first described them in the early 1900s. How or why these deposits develop in the first place is unknown.
Lewy bodies that form in the brain stem and the rest of the brain decrease the amount of available dopamine and acetylcholine. Both of these chemicals are neurotransmitters (chemical messengers in the brain and nervous system) which work together so that messages controlling motor movement are properly sent and received. These deficits in neurotransmitters cause movement problems referred to as "Parkinsonian" symptoms (described below), as well as disrupting memory, learning, perception, thinking, and behavior.
Interestingly, Lewy bodies are also found in the brains of those with Parkinson's Disease and - sometimes - even Alzheimer's Disease, making diagnosing all of these illnesses much more complicated.
Age is the only definitive risk factor for Lewy Body Dementia. A person's risk for developing this type of dementia increases as age increases, with most cases occurring between the ages of 50 and 85. Sometimes, LBD runs in families, but for the most part, the disease occurs in people with no family history of the disorder.
As described in more detail below, some researchers also consider REM Sleep Behavior Disorder a significant risk factor for developing Lewy Body Dementia.
http://www.mentalhelp.net/poc/view_doc. ... c&id=13152
Symptoms of Lewy Body Dementia
Carrie Hill, Ph.D. and Natalie Reiss, Ph.D.
Updated: Jul 3rd 2008
Cognitive: The cognitive symptoms of people with LBD may fluctuate frequently (moment-to-moment, hour-to-hour, or day-to-day). Individuals will be alert (and seem "normal"), and then suddenly become extremely confused, unable to pay attention, or unable to make decisions. Episodes of cognitive impairment may last hours or days.
In addition to problems with attention and reasoning, people with LBD often have impaired visuospatial skills (e.g., impaired depth perception or the ability to see the world in three dimensions; impaired object orientation or understanding how objects appear in space; impaired ability to navigate about the world; and/or illusions, such as mistaking a coat rack for a person).
People with LBD eventually develop impaired memory, but this type of problem does not usually occur until they have had the disease for a period of time. In other words, unlike Alzheimer's Disease, memory symptoms are not the first problem that people with Lewy Body Dementia (or family members) notice.
Movement: People with Lewy Body Dementia "look" somewhat different from people with Alzheimer's Disease and Vascular Dementia, primarily because they have Parkinson's-like symptoms. Parkinson's Disease is a slowly progressive neurological condition that affects the brain and spinal cord, creating symptoms such as tremors (shaking) and rigidity (stiffness). Parkinsonian symptoms in LBD include slow movements, a stooped posture, stiffness in the arms or legs, tremors, a shuffling walking pattern, a mask-like appearance and/or a blank stare, and frequent falls.
Other symptoms: Other characteristic symptoms that are often disturbing for both affected individuals and their family members set Lewy Body Dementia apart from other types of dementia:
* Recurrent, vivid visual hallucinations (seeing things that are not really there, such as an attacker in the bedroom) that are extremely difficult to separate from reality. Hallucinations occur most often when people are most confused and can also include sounds, tastes, and smells that aren't truly present.
* Fluctuating alertness periods (extreme drowsiness followed by sudden bursts of energy) that make it difficult for family members to predict or assess how their relative is doing. People with LBD may also faint repeatedly and without warning.
* Severe sleep problems (called REM Sleep Behavior Disorder or RBD). During REM sleep (the stage of deep sleep characterized by rapid eye movements), people with LBD will move, gesture, and/or speak. They often seem to be acting out their dreams, and may accidentally hit a spouse or fall out of bed. In addition, some people become extremely confused when they first wake up (and not know the difference between a dream and reality). REM Sleep Behavior Disorder can occur years before people start to show signs of dementia and impaired motor movements. As mentioned above, RBD may be a significant risk factor for developing Lewy Body Dementia.
* Severe sensitivity to neuroleptics (also called antipsychotic drugs, these medications are often used to treat psychotic disorders like schizophrenia) occurs in up to 50% of individuals with LBD. These medications can worsen cognitive and movement symptoms and/or increase hallucinations. People with LBD can also develop Neuroleptic Malignant Syndrome, which is a life-threatening illness characterized by muscle rigidity, high fever, problems with the autonomic system (see below), and severe confusion and fluctuating alertness.
* The autonomic nervous system keeps our bodies in balance, or homeostasis, by controlling functions such as heart rate, digestion, breathing rate, perspiration, pupil dilations, the discharge of urine, and sexual arousal. Individuals with LBD often have autonomic system dysfunction, which can lead to blood pressure fluctuations, heart rate variability, sexual dysfunction (e.g., impotence), constipation/urinary problems, excessive or decreased sweating, dry eyes/mouth, and difficulty swallowing.
* Other psychiatric issues such as delusions (false, fixed beliefs), aggression, and/or depression are not uncommon in individuals with LBD. Aggressive behavior can be triggered by infections (e.g., urinary tract infections), medications, or misinterpretation of the environment or interpersonal interactions due to confusion and/or hallucinations.
http://www.mentalhelp.net/poc/view_doc. ... c&id=15335
Diagnosis and Treatment of Lewy Body Dementia
Carrie Hill, Ph.D. and Natalie Reiss, Ph.D.
Updated: Jul 3rd 2008
Diagnosis of Lewy Body Dementia
No single test can be used to definitively diagnose Lewy Body Dementia. Currently, Lewy bodies can only be identified through autopsy. Therefore, the process of diagnosis is similar to that of diagnosing Alzheimer's Disease and is designed to rule out other possible causes of a person's symptoms.
A thorough diagnostic evaluation will include physical and neurological examinations (with associated laboratory tests), patient and family interviews (including a detailed medical and medication history), and psychological/psychiatric and neuropsychological testing. Click here to return to our previous in-depth discussion of each of these components of a diagnostic workup. In addition, brain imaging (CT, MRI, PET or SPECT) scans may be performed.
The following tests may be used in a psychological/psychiatric evaluation:
* The Geriatric Depression Scale (GDS) - The GDS is a screening instrument used to detect depression among older adults (click here to return to our previous discussion of this instrument). Clinicians may use it to help determine whether depression coexists with Lewy Body Dementia.
* Mental status exam - As described before, mental status exams assess memory, concentration, and other cognitive skills. Interestingly, some people who meet the diagnostic criteria for LBD will score in the "normal" range of some cognitive screening tools such as the MMSE (described previously, click here to return to that discussion). As we mentioned in the discussion on Alzheimer's disease, relying solely on an MMSE score to confirm (or discard) a diagnosis is inappropriate.
* Neuropsychological testing - As described earlier, neuropsychologists administer tests that allow them to better understand a person's particular pattern of cognitive impairment and preserved abilities. Neuropsychologists assessing someone for LBD will give particular consideration to attention, concentration, and visuospatial skills, particularly in the early stages of the illness when memory problems may not be detected.
Treatment for Lewy Body Dementia
Lewy Body Dementia is very difficult to treat. Unfortunately, people with this illness often cannot tolerate antipsychotic medications, which might otherwise be helpful in treating symptoms like delusions and hallucinations. Negative reactions to antipsychotic medications can include a worsening of symptoms, extreme muscle rigidity, or even catatonia - which can take the form of apathy and complete motionlessness or constant overexcitement. In addition, as discussed before, people with LBD who use antipsychotic medications may develop a serious and potentially life threatening condition called Neuroleptic Malignant Syndrome.
Medications: No drugs have been approved by the FDA to specifically treat Lewy Body Dementia, but Alzheimer's medications are sometimes helpful. In fact, some researchers assert that people with Lewy Body Dementia respond better to cholinesterase inhibitors (drugs that increase the level of acetylcholine in the brain, such as donepezil, rivastigmine, or galantamine; click here to return to our discussion of these medications) than individuals with any other type of dementia.
Because Parkinsonian symptoms are prevalent in Lewy body dementia, medications used for Parkinson's Disease (e.g., Sinemet) which boost the production and effectiveness of the neurotransmitter dopamine (click here to return to our discussion of how this brain chemical plays a role in LBD) are often used to treat movement symptoms. However, they can also increase confusion, delusions, and hallucinations.
Antidepressants (medications typically used to treat mood disorders such as depression and problems with anxiety) and anticonvulsants (medications typically used to treat seizure disorders) are sometimes used to treat the sleep and mood problems associated with Lewy Body Dementia, but they can also increase a person's level of confusion and motor problems.
Other treatments: Behavior management strategies - which are discussed in more detail later - are also useful for managing the difficult behavioral symptoms of Lewy Body Dementia.
Specific lifestyle changes may also help manage symptoms of LBD. Reducing caffeine intake, increasing physical activity during the day, and providing relaxing activities in the evening can improve sleep patterns and reduce the incidence of violent outbursts during the night while a person is sleeping.
Prognosis for Lewy Body Dementia
Unfortunately, there is currently no cure for Lewy Body Dementia. The average life expectancy for people with LBD after the onset of symptoms is 5 to 8 years. However, individuals with Lewy Body Dementia have lived anywhere between 2 and 20 years depending on their age, the severity of their symptoms, and their other medical conditions.
The course of Lewy Body Dementia can vary across people, but is usually "progressive but vacillating." In other words, across time, people decline, but there may be periods of return to a higher functioning level. This decline may be exacerbated by medications and/or infections/diseases.
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