Lewy body disease

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.