Dementia with Lewy bodies (DLB), also known as Lewy body disease, is the second most frequent cause of age-related neurodegenerative dementia. At least 5 percent of people aged 85 and older are thought to suffer from this little known but not uncommon and devastating disease. In the UK approximately 100,000 are thought to suffer from DLB.
There are presently over 700,000 people with dementia in the UK and this number is projected to rise to 1,000,000 by 2021 unless cures are found. There are currently about five million people with dementia in the European Union. These figures represent only patients; caregivers double or treble the number of people whose lives are directly affected by dementia and relations and friends increase these numbers further.
DLB shares mental symptoms, such as confusion and loss of memory, with Alzheimer's disease and motor symptoms, such as gait and slow movement, with Parkinson's disease. For that reason it is often misdiagnosed. Accurate diagnosis is essential for successful treatment of the disease: people with DLB are characteristically highly sensitive to certain drugs which can worsen unpleasant symptoms or even be fatal.
DLB was virtually unknown until a decade ago. Due in large part to a close collaboration between researchers in the UK, Japan and the USA, it is now recognised as a distinct medical condition and not a variant of Alzheimer's or Parkinson's diseases.
Symptoms and Diagnosis
Each case of dementia with Lewy bodies (DLB) is as individual as the person who suffers from it. Different people will show different combinations of symptoms. At present a diagnosis of DLB can only be confirmed by autopsy but a careful clinical evaluation of the patient and his or her symptoms can, in many cases, form the basis for making a reasonably confident lifetime diagnosis.
The symptoms of DLB can be grouped as central, core, suggestive or supportive .
The central symptom of dementia with Lewy bodies is dementia , or progressive mental decline serious enough to interfere with normal daily activities. Significant memory loss may not develop until later. There may also be problems with attention, problem solving and spatial awareness. This can easily be mistaken for Alzheimer's disease or for Parkinson's disease (PD) with dementia.
Core symptoms: Dementia along with the existence of one of the core symptoms listed below can lead to a diagnosis of possible DLB. Two of the core symptoms in addition to dementia and the diagnosis of DLB is probable.
Fluctuating states of consciousness
Typically people with DLB will experience extreme swings from alertness to confusion. These occur unexpectedly over any period of time, from minutes to days. If a person who has been diagnosed with Alzheimer's disease can sometimes play cards or follow a game of cricket, it could be DLB instead.
Two-thirds of patients with DLB experience vivid and recurrent visual hallucinations. For some people these are pleasant visions of animals or small children but others have terrifying, threatening hallucinations, which cause them - and their carers - intense distress.
People with DLB experience motor difficulties seen in PD patients such as slow movement (bradykinesia), rigidity and falls but sometimes do not experience the tremor which is characteristic of PD. With DLB there tends to be greater difficulty in walking, balance and facial impassiveness than in PD [2, 3]. In both diseases the patient may suffer from autonomic symptoms such as sudden drop in blood pressure upon standing, difficulty in swallowing , incontinence or constipation [4, 5].
Suggestive symptoms: One or more of these symptoms in addition to one or more core symptoms can lead to a diagnosis of probable DLB. One or more suggestive symptoms without any core symptoms is enough for a diagnosis of possible DLB.
Disturbances in REM sleep
REM sleep is the deep sleep in which people dream. A certain amount of good, undisturbed REM sleep is necessary in order for people to function efficiently. DLB sufferers may talk in their sleep or act out their dreams. Some times this is so marked that the sufferer may fall off the bed.
Severe sensitivity to neuroleptic drugs
Sometimes people with DLB are prescribed neuroleptic (anti-psychotic) drugs to help with their symptoms. This should only be done by someone experienced in the illness as many of these drugs can be extremely harmful or even fatal to people with DLB (see Treatment).
Supportive symptoms: These may assist in a diagnosis of DLB but are not conclusive in themselves.
Problems with swallowing or continence
Other hallucinations ( hearing, smelling or feeling things)
A diagnosis of DLB is less likely if the person has had a stroke or other illness which may have affected motor or mental ability. top
What is Dementia with Lewy Bodies?
Dementia with Lewy Bodies (DLB) is the second most common cause of dementia in older people, affecting approximately 130,000 individuals in the UK together with their carers and relations. It is sometimes also referred to as Lewy body disease or Lewy Body dementia.
What are Lewy bodies?
Lewy bodies are deposits of abnormal proteins inside brain cells and are named after Dr. Friedrich Lewy who first described them under the microscope in 1912. Lewy bodies are associated with the death of brain cells and subsequent deterioration of the brain.
What are the symptoms of DLB?
DLB shares characteristic symptoms of Alzheimer's disease (AD) and Parkinson's disease (PD), with both mental and motor problems. There are problems with memory, concentration and other cognitive abilities similar (but not identical) to AD and difficulties with balance, movement and autonomic functioning (bladder, bowel, blood pressure control) as in PD.
How is it different from AD and PD?
People with DLB characteristically experience dramatic swings in their level of alertness, fluctuating from clarity to confusion, often in a short period of time. Visual hallucinations are common in DLB, typically of people and animals, which are vivid but silent. Although they may have other Parkinsonian symptoms, the tremor associated with PD is not always present. Because DLB, AD and PD share so many symptoms, diagnosis of DLB can be difficult and requires an experienced specialist e.g. in old age psychiatry or neurology. Accurate diagnosis is essential for successful treatment.
What treatment is available?
At present there is no cure for DLB but symptoms can often be alleviated. Research indicates that some AD drugs may be helpful for people with DLB. Parkinson's drugs may help some people with the motor symptoms but can increase confusion in others. Prescribing should generally be started by a doctor with experience of DLB. Some types of drug (antipsychotics) drugs should not be given to people with DLB as they can be extremely harmful. Non-medical interventions such as a daily routine, physical activity where possible and changes to the environment are all helpful in managing daily life.