Lewy Body Dementia

Question 1

Who does DLB affect?

Answer 1

-Common
-Incidence is around 4% of new cases

Question 2

What causes DLB?

Answer 2

-Shares characteristics with Alzheimer’s and Parkinson’s
-Characterised by eosinophilic intracytoplasmic neuronal inclusion bodies (Lewy bodies) in the brainstem and neocortex
-A spectrum of Lewy body disorders that include DLB, PD and PD-associated dementia

Question 3

How does DLB present?

Answer 3

-Dementia is usually the presenting feature –> memory loss, problem solving decline, spatial awareness difficulties
-Fluctuating levels of awareness and attention
-Mild Parkinsonism, falls
-Visual hallucinations
-Sleep disorders
-Fainting spells

Question 4

What are the diagnostic criteria for DLB?

Answer 4

-Presence of dementia
-2-3 of the 3 core features:
–Fluctuating attention and concentration
–Recurrent well-formed visual hallucinations
–Spontaneous Parkinsonism
-In the absence of 2 core features, probable DLB diagnosis can be made if there is 1+ suggestive feature:
–REM sleep behaviour disorder
–Severe neuroleptic sensitivity
–Low dopamine transporter uptake in the basal ganglia seen in SPECT / PET

Question 5

What are the differential diagnoses for DLB?

Answer 5

-Other forms of dementia especially PD dementia
-Intracranial tumours
-Cerebrovascular events

Question 6

How would you investigate a patient with DLB?

Answer 6

-Usually a clinical diagnosis
- Basic dementia screen (as in Alzheimer’s and VaD)
-Dopaminergic iodine labelled PET scanning can be useful (shows decreased dopamine uptake)
-Clinical cognitive assessment eg MMSE, GPCOG etc

Question 7

What treatments would you discuss with a DLB patient?

Answer 7

-Same general measures as other dementias
-People with DLB must not drive
-AChEI’s eg rivastigmine can help treat cognitive decline
-Avoid neuroleptic drugs as severe sensitivity reactions are more likely in DLB patients
-Anti-Parkinsonian treatment may worsen psychosis