Dementia with Lewy bodies is the second most common type of dementia. It is estimated to account for 10% – 15% of all cases and is closely related to Alzheimer’s disease and Parkinson’s disease.
Lewy bodies are the cause of Parkinson’s disease (PD) and Dementia with Lewy bodies (DLB). They are tiny particles of protein that develop inside nerve cells and prevent the cells from communicating properly by disrupting the important chemical messages between them, eventually causing the cells to die.
The most common symptoms of dementia with Lewy bodies are:
– Problems with mental abilities
Affecting concentration, attention, memory, language and the ability to judge distances.
– Hallucinations and delusions:
This is the most characteristic neuropsychiatric feature of DLB. 46% of the cases occur at some point during the course of the illness in. Visual hallucinations are often of people or animals and are detailed and convincing to the person with dementia.
– Movement problems:
Extrapyramidal symptoms such as irregular movements, continuos spams and muscle contractions, rigidity, motor restlessness, and tremor.
– Sleep disturbance:
Rapid-eye-movement (REM) sleep-wakefulness dissociations and R.EM sleep behaviour disorder, daytime hypersomnolence, visual hallucinations, and cataplexy.
People with Lewy body disease are very sensitive to some tranquillisers known as antipsychotic or neuroleptic drugs, and their use should be avoided if at all possible.
Treatment of DLB is somewhat complicated, as many drugs tend to exacerbate symptoms if wrongly prescribed or taking a high dose of Levodopa, for example, a drug commonly used in Parkinson’s disease, may be effective in treating motor symptoms associated with parkinsonism in DLB, but if doses are too high they are often associated with increased confusion and hallucinations.
Cholinesterase inhibitor drugs, which are often used to treat AD, are somewhat effective and relatively safe in treating neuropsychiatric and cognitive symptoms, although they are not entirely free from side effects, especially gastrointestinal.
Since no specific tests exist to precisely diagnose DLB, the clinician must resort to obtaining a detailed medical history from the patient and an informant, and perform cognitive tests and neurological examinations.
As with most cases of dementia, it is often clinically difficult to identify typical cases of a specific dementia syndrome, with most patients presenting features of multiple syndromes. This is challenging with regards to both diagnosis and treatment. Hopefully, new treatments and more precise diagnostic procedures will be discovered in the near future.
source: McKeith, I. (2004), Dementia with Lewy bodies, Dialogues In Clinical Neuroscience, 6(3), pp. 333-341