Dementia with Lewy bodies
The Lewy body dementia or Lewy body dementia (English: Dementia with Lewy bodies, abgek. DLB ) is after Alzheimer's disease is the second most common neurodegenerative dementia in old age and may occur both as an independent disease as well as secondary, as part of a existing Parkinson's disease. The Lewy body dementia makes up about 20 % of all dementias.
History
Is named the disease after Friedrich H. Lewy (1885-1950), a German neurologist. In his book chapter on the " palsy " (now Parkinson's disease ), he described the first time, later named after him Lewy bodies. He found working at the Berlin clinic, these changes in the nucleus basalis of Meynert and dorsal motor nucleus of the vagus nerve of Parkinson's patients.
Classification
- Diffuse Lewy body disease or dementia with Lewy bodies
- Parkinson's disease with concomitant Alzheimer's pathology
- Lewy body variant of Alzheimer's disease
However, a clear distinction can often be made only post mortem by histological examination of the changes in the brain.
The division in the group with dementia presence of diffuse cortical Lewy bodies was made some time after the consensus criteria for Lewy body disease, which state that at least two of the following three criteria must be met ( McKeith et al 1996. )
- Fluctuating cognitive deficits (especially attention)
- Repetitive detailed visual hallucinations
- Extrapyramidal disorders (involuntary motor disturbances )
Pathogenesis
The Lewy bodies, which also account for this disease were first discovered in Parkinson disease. It is to eosinophilic inclusions in the cytoplasm of nerve cells ( neurons) in the cerebral cortex and brain stem. These inclusions are abnormal aggregates of protein which reduce the formation of the second messenger ( neurotransmitter ) dopamine, causing, inter alia, to the typical symptoms of Parkinson's disease.
After the α -synuclein pathology a neuropathological staging in four stages today postmortem usual.
Clinic
The Lewy Body Dementia is typically characterized by strong fluctuations of symptoms. Attention, concentration, alertness (vigilance ) and other cognitive functions may vary depending on the day's form. Overall, the disease is but progressive.
Other typical symptoms
- Disturbances in REM sleep
- Visual hallucinations (which can render the patient often detailed)
- Syncope and falls
- Depression and mania
Diagnosis
The clinical diagnosis is based on the current consensus criteria by McKeith et al. Criteria for the clinical diagnosis of dementia with Lewy bodies ( DLB; shortened by McKeith et al. ) Are two of the key characteristics fulfills, one speaks of a probable DLB, with a core feature of a possible DLB.
Obligate feature: Increasing cognitive disorders associated with impairments in social or professional environment.
Core characteristics: Cognitive fluctuations, especially the attention, recurrent, usually detailed visual hallucinations, motor Parkinson's symptoms
Indicative features: falls, syncope, transient disturbances of consciousness, hallucinations in other sensory modalities, delusions, REM sleep behavior disorders, neuroleptic sensitivity, detected by SPECT or PET imaging, decreased dopamine transporter uptake in the striatum (SPECT = Single photon emission computed tomography ( single photon emission tomography ), PET = positron emission tomography, REM = rapid eye movement ).
Differential diagnosis of Alzheimer's disease (AD): Visual hallucinations have a high specificity to distinguish between AD and DLB (99%), the restrictions visuokonstruktiven a high sensitivity ( 74%). Cognitive fluctuations and speak for DLB against AD.
The frequent behavioral disorders in dementia patients have recently been called BPSD (abbreviation for " Behavioural and Psychological Symptoms of Dementia" ). This term is now the apathy ( 76.0 %), "deviant motor behavior " (eg aimless wandering ) ( 64.5 %), eating disorders ( eating Unessbarem ) ( 63.7 %), irritability / lability ( 63.0 %), agitation / aggression ( 62.8 %), insomnia ( 53.8 % ), depression / dysphoria ( 54.3 % ), anxiety ( 50.2 %), delusions ( 49.5 %), disinhibition (29, 5% ), hallucinations ( 27.8 %), and euphoria ( 16.6 %).
Therapy
Drug therapy is only symptomatic. Since it is assumed that in dementing diseases pathophysiologically is a lack of acetylcholine, is therapeutically addressed, however, by inhibiting the enzyme that breaks down acetylcholine. Acetylcholinesterase inhibitors such as, for example, Donepezil or galantamine, which are, however, allowed in Germany only for Alzheimer's dementia represent a potential treatment represents the therapy should generally be initiated early, since they only slow down the course, but can not be undone. The effects could be far demonstrated only in studies and complex test systems. For the patient and his relatives, these effects are probably not noticeable and probably have no influence on their everyday life.
Antipsychotic drugs are rather unsuitable, since patients often react with reinforced side effects on it. Nevertheless, when neuroleptics are indexed, an atypical antipsychotic agent may be tried, but which in principle have no benefits.
Recently, non-pharmacological interventions for behavioral disturbances of dementia are favored. Only if this is not sufficient, will be resorted to medical aid.
Prophylaxis
Both physical and mental activity has been shown to significantly reduce the risk of developing a dementia syndrome.