User:Mr. Ibrahem/Dementia with Lewy bodies
Medical condition / From Wikipedia, the free encyclopedia
Dementia with Lewy bodies (DLB) is a type of dementia accompanied by changes in sleep, behavior, thinking, movement, and automatic bodily functions.[9] Memory loss is not always an early symptom.[10] The disease worsens over time and is usually diagnosed when cognitive decline interferes with normal daily functioning.[11][2] Heart function and every level of gastrointestinal function—from chewing to defecation—can be affected, constipation being one of the most common symptoms.[9][12] Low blood pressure upon standing can also occur.[9] It can affect behavior; mood changes such as depression and lack of interest are common.[11]
Dementia with Lewy bodies | |
---|---|
Other names | Diffuse Lewy body disease |
Microscopic image of a Lewy body (arrowhead) in a neuron of the substantia nigra; scale bar=20 microns (0.02mm) | |
Specialty | Neurology, psychiatry |
Symptoms | Dementia, abnormal behavior during REM sleep, fluctuations in alertness, visual hallucinations, slowness of movement[1] |
Usual onset | After the age of 50,[2] median 76[3] |
Duration | Long term[4] |
Causes | Unknown[4] |
Diagnostic method | Based on symptoms and biomarkers[1] |
Differential diagnosis | Alzheimer's, Parkinson's disease dementia, certain mental illnesses, vascular dementia[5] |
Medication | Acetylcholinesterase inhibitors such as donepezil and rivastigmine;[6] melatonin[7] |
Prognosis | Average survival 8 years from diagnosis[4] |
Frequency | About 0.4% of persons older than 65[8] |
The exact cause is unknown,[4] but involves widespread deposits of abnormal clumps of protein in neurons of the diseased brain.[13] Most people do not have affected family, although occasionally it runs in a family.[4] Known as Lewy bodies (discovered in 1912 by Frederic Lewy)[14] and Lewy neurites, these clumps affect both the central nervous system and the autonomic nervous system.[15] REM sleep behavior disorder (RBD)—in which people lose the muscle paralysis that normally occurs during REM sleep and act out their dreams—is a core feature.[11] RBD may appear years or decades before other symptoms.[11] Other core features are visual hallucinations, marked fluctuations in attention or alertness, and parkinsonism (slowness of movement, trouble walking, or rigidity).[11] A presumptive diagnosis can be made if several disease features or biomarkers are present; the diagnostic workup may include blood tests, neuropsychological tests, imaging, and sleep studies.[11] A definitive diagnosis usually requires an autopsy.[11][2] Together with Parkinson's disease dementia, DLB is one of the two Lewy body dementias.[9]
There is no cure or medication to stop the disease from progressing,[16] and people in the latter stages of DLB may be unable to care for themselves.[17] Treatments aim to relieve some of the symptoms and reduce the burden on caregivers.[9][18] Medicines such as donepezil and rivastigmine are effective at improving cognition and overall functioning, and melatonin can be used for sleep-related symptoms.[19] Antipsychotics are usually avoided, even for hallucinations, because severe and life-threatening reactions occur in almost half of people with DLB,[20] and their use can result in death.[21] Management of the many different symptoms is challenging, as it involves multiple specialties and education of caregivers.[22][9][11]
DLB is a common form of dementia,[2] but the number of people affected is not known accurately[23][24] and many diagnoses are missed.[25] It typically begins after the age of fifty[2] and people with the disease live about eight years after diagnosis.[4] The disease was first described by Kenji Kosaka in 1976.[26]