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Lewy Body Dementia

August 19, 2014

GraceWhat Is LBD?
By Lewy Body Dementia Association

LBD affects an estimated 1.3 million individuals and their families in the United States. Because LBD symptoms can closely resemble other more commonly known diseases like Alzheimer’s and Parkinson’s, it is currently widely underdiagnosed. Many doctors or other medical professionals still are not familiar with LBD.

LBD is an umbrella term for two related diagnoses. LBD refers to both Parkinson’s disease dementia and dementia with Lewy bodies. The earliest symptoms of these two diseases differ, but reflect the same underlying biological changes in the brain. Over time, people with both diagnoses will develop very similar cognitive, physical, sleep, and behavioral symptoms.

While it may take more than a year or two for enough symptoms to develop for a doctor to diagnose LBD, it is critical to pursue a formal diagnosis. Early diagnosis allows for important early treatment that may extend quality of life and independence.

LBD is a multisystem disease and typically requires a comprehensive treatment approach. This approach involves a team of physicians from different specialties who collaborate to provide optimum treatment of each symptom without worsening other LBD symptoms. Many people with LBD enjoy significant improvement of their symptoms with a comprehensive approach to treatment, and some can have remarkably little change from year to year.

Some people with LBD are extremely sensitive or may react negatively to certain medications used to treat Alzheimer’s or Parkinson’s in addition to certain over-the-counter medications.

Who was Lewy?

In the early 1900s, while researching Parkinson’s disease, the scientist Friederich H. Lewy discovered abnormal protein deposits that disrupt the brain’s normal functioning. These Lewy body proteins are found in an area of the brain stem where they deplete the neurotransmitter dopamine, causing Parkinsonian symptoms. In Lewy body dementia, these abnormal proteins are diffuse throughout other areas of the brain, including the cerebral cortex. The brain chemical acetylcholine is depleted, causing disruption of perception, thinking and behavior. Lewy body dementia exists either in pure form, or in conjunction with other brain changes, including those typically seen in Alzheimer’s disease and Parkinson’s disease.

Lewy body dementia symptoms and diagnostic criteria

Every person with LBD is different and will manifest different degrees of the following symptoms. Some will show no signs of certain features, especially in the early stages of the disease. Symptoms may fluctuate as often as moment-to-moment, hour-to-hour or day-to-day. NOTE: Some patients meet the criteria for LBD yet score in the normal range of some cognitive assessment tools. The Mini-Mental State Examination (MMSE), for example, cannot be relied upon to distinguish LBD from other common syndromes.

The latest clinical diagnostic criteria for dementia with Lewy bodies (DLB) categorizes symptoms into three types, listed below. A diagnosis of Parkinsons’ disease dementia (PDD) requires a well established diagnosis of Parkinson’s disease that later progresses into dementia, along with very similar features to DLB. A rather arbirary time cutoff was established to differentiate between DLB and PDD. People whose dementia occurs before or within 1 year of Parkinson’s symptoms are diagnosed with DLB. People who have an existing diagnosis of Parkinson’s for more than a year and later develop dementia are diagnosed with PDD.
Central feature

Progressive dementia – deficits in attention and executive function are typical. Prominent memory impairment may not be evident in the early stages.

Core features

Fluctuating cognition with pronounced variations in attention and alertness.
Recurrent complex visual hallucinations, typically well formed and detailed.
Spontaneous features of parkinsonism.

Suggestive features

REM sleep behavior disorder (RBD), which can appear years before the onset of dementia and parkinsonism.
Severe sensitivity to neuroleptics occurs in up to 50% of LBD patients who take them.
Low dopamine transporter uptake in the brain’s basal ganglia as seen on SPECT and PET imaging scans. (These scans are not yet available outside of research settings.)

Supportive features

Repeated falls and syncope (fainting).
Transient, unexplained loss of consciousness.
Autonomic dysfunction.
Hallucinations of other senses, like touch or hearing.
Visuospatial abnormalities.
Other psychiatric disturbances.

A clinical diagnosis of LBD can be probable or possible based on different symptom combinations.

A probable LBD diagnosis requires either:

Dementia plus two or more core features, or
Dementia plus one core feature and one or more suggestive features.

A possible LBD diagnosis requires:

Dementia plus one core feature, or
Dementia plus one or more suggestive features.

Symptoms Explained

In this section we’ll discuss each of the symptoms, starting with the key word: dementia. Dementia is a process whereby the person becomes progressively confused. The earliest signs are usually memory problems, changes in their way of speaking, such as forgetting words, and personality problems. Cognitive symptoms of dementia include poor problem solving, difficulty with learning new skills and impaired decision making.

Other causes of dementia should be ruled out first, such as alcoholism, overuse of medication, thyroid or metabolic problems. Strokes can also cause dementia. If these reasons are ruled out then the person is said to have a degenerative dementia. Lewy Body Dementia is second only to Alzheimer’s disease as the most common form of dementia.

Fluctuations in cognition will be noticeable to those who are close to the person with LBD, such as their partner. At times the person will be alert and then suddenly have acute episodes of confusion. These may last hours or days. Because of these fluctuations, it is not uncommon for it to be thought that the person is “faking”. This fluctuation is not related to the well-known “sundowning” of Alzheimer’s. In other words, there is no specific time of day when confusion can be seen to occur.

Hallucinations are usually, but not always, visual and often are more pronounced when the person is most confused. They are not necessarily frightening to the person. Other modalities of hallucinations include sound, taste, smell, and touch.

Parkinsonism or Parkinson’s Disease symptoms, take the form of changes in gait; the person may shuffle or walk stiffly. There may also be frequent falls. Body stiffness in the arms or legs, or tremors may also occur. Parkinson’s mask (blank stare, emotionless look on face), stooped posture, drooling and runny nose may be present.

REM Sleep Behavior Disorder (RBD) is often noted in persons with Lewy Body Dementia. During periods of REM sleep, the person will move, gesture and/or speak. There may be more pronounced confusion between the dream and waking reality when the person awakens. RBD may actually be the earliest symptom of LBD in some patients, and is now considered a significant risk factor for developing LBD. (One recent study found that nearly two-thirds of patients diagnosed with RBD developed degenerative brain diseases, including Lewy body dementia, Parkinson’s disease, and multiple system atrophy, after an average of 11 years of receiving an RBD diagnosis. All three diseases are called synucleinopathies, due to the presence of a mis-folded protein in the brain called alpha-synuclein.)

Sensitivity to neuroleptic (anti-psychotic) drugs is another significant symptom that may occur. These medications can worsen the Parkinsonism and/or decrease the cognition and/or increase the hallucinations. Neuroleptic Malignancy Syndrome, a life-threatening illness, has been reported in persons with Lewy Body Dementia. For this reason, it is very important that the proper diagnosis is made and that healthcare providers are educated about the disease.
Other Symptoms

Visuospatial difficulties, including depth perception, object orientation, directional sense and illusions may occur.

Autonomic dysfunction, including blood pressure fluctuations (e.g. postural/orthostatic hypotension) heart rate variability (HRV), sexual disturbances/impotence, constipation, urinary problems, hyperhidrosis (excessive sweating), decreased sweating/heat intolerance, syncope (fainting), dry eyes/mouth, and difficulty swallowing which may lead to aspiration pneumonia.

Other psychiatric disturbances may include systematized delusions, aggression and depression. The onset of aggression in LBD may have a variety of causes, including infections (e.g., UTI), medications, misinterpretation of the environment or personal interactions, and the natural progression of the disease.

Source: http://www.lbda.org/category/3437/what-is-lbd.htm#sthash.ywg42Yjb.dpuf , http://www.lbda.org/content/symptoms#sthash.Qlfadtu1.dpuf

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