LEWY BODY DEMENTIA
General outline: A neurodegenerative
disorders which affects subcortical and cortical brain, presents symptoms
of Parkinson's disease, fluctuations of attention, and hallucinations.
Synonyms: Lewy body variant of Alzheimer's disease, diffuse
Lewy body disease, dementia with Lewy bodies, senile dementia of Lewy body
Symptoms: The key clinical features of dementia with LBD
are hallucinations and fluctuations of cognitive ability in combination with
spontaneous Parkinsonian signs. Fluctuation of cognition, prominent visual
hallucinations, mild Parkinsonian signs (akinesia, rigidity), unexpalined
falls. Memory impairment may be mild at the early stage, spatial disorientation.
Course: Gradually progressive, symptoms gradually accumulate,
average survival is 6 to 7 years. Age of onset 50 to 83, death 68 to 92,
average survival from diagnosis 5 - 7 years. DLB tends to progress faster
Caregiver problems: Fluctuation of cognitive ability may
cause problems, non-acceptance of disease, presence of hallucinations, probability
of falls, safety of environment, possibility of falling asleep during the
Epidemiology: Abnormal accumulation of an abnormal protein
= synuclein in Lewy bodies, which cause neurodgeneration. Reason is not clear.
A few families have been described with mutations in the synuclein on chromosome
4. Apolipoliprotein E is not a risk factor.
Aetiology: Epidemiological data: Of all the rare causes
of dementia LBD is considered to be the most frequent, accounting for 10
to 15 per cent of all dementias. Male to female ratio 1.5 : 1 (in contrast
Diagnostic procedures: Functional imaging (PET) may show a different picture than in AD
Treatment and rehabilitation: Treatment is purely symptomatic.
Using medications should be used with great caution. Symptomatic treatment
for hallucinations. Patients are over-sensitive to classical neuroleptics.
The use of some of these medications has even caused death. If any neuroleptic
treatment, then atypical compounds should be used with due caution. Parkinsonian
signs should be treated with levodopa. However, these medications may aggravate
Ongoing research / Clinical trials: On small groups of
patients cholinesterase inhibitors (rivastigmine) have been tried in LBD
patients showing benefits and cognitive and non-cognitive symtoms.
Available services There is no specific caregiver association. Specialist groups: Newcastle
Further reading Diagnostic criteria (McKeith), Lancet paper on treatment.