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 type
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 than
AD.
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 day.
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 to
AD).
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 hallucinations.
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.
