Lecture 10: Dementia with Lewy bodies Flashcards
Dementia with Lewy bodies:
- Progressive cognitive decline
- Core features
- DLB:
- Progressive cognitive decline
- Core features
- Parkinsonism
- Visual hallucinations
- Fluctuations cognitive functioning and arousal
Dementia with Lewy bodies
- epidemiology (prevalence)
- typical age
- mean survival time
- most frequent neurodegenerative dementia after AD (VaD more common but its not neurodegenerative)
- third most common form dementia, after AD and vascular dementia
- 5 - 20% of dementia cases
- first described in 1961
- symptoms usually appear after 60.
- Early onset rare
- No increase prevalence with age
- Mean survival time 8-10 years
Dementia with Lewy bodies
- Neuropathology
- Lewy bodies.
- Discovered by Fritz Heinrich Lewy in 1910
- abnormal aggregates of proteins inside nerve cells
Neuropathology
- Main component Lewy bodies:
- Lewy neurites:
- DLB example class neurodegenerative diseases:
- ¤Similarities DLB and PD:
- Main component Lewy bodies: alpha-synuclein
- protein abundant in brain
- for reasons unclear, alpha-synuclein clumps together
- Lewy neurites, common feature in DLB
- neurites containing abnormal alpha-synuclein
- neurite: any projection from cell body
- DLB example class neurodegenerative diseases - synucleinopathies
- other example Parkinson’s Disease (PD)
- Lewy bodies and Lewy neuritis in nerve cells PD
- Similarities DLB and PD
- Symptoms DLB, PD and PD dementia overlap
- Effects on cognition, movement and behaviour

Progression Lewy Body Pathology
- Braak et al (2003) staging LB pathology:
- LB pathology in DLB similar as PD:
Braak et al (2003) staging LB pathology:
- I – VI peripheral NS - brainstem - cortex
LB pathology in DLB similar as PD:
- Most autopsy cases: LB in cortical areas
advanced Braak stage

Neuropathology
- DLB - LB (lewy Bodies) in
- PD (Parkinson’s Disease) – LB in
- DLB - LB in
- cortex and limbic areas
- subcortical (locus coerules, substantia nigra, nucleaus basalis of Meynert)

Neuropathology
- LB can occur in:
- AD pathology in DLB?
- Lewy bodies in 20-35% older persons with dementia, not all DLB
- Lewy bodies not common in healthy persons
- Many DLB patients also AD pathology (amyloid plaques)
- Up to 75-90% of patients with DLB
- Tangles less common in DLB
Neuropathology
- cholinergic neurons:
- Loss of cholinergic neurons and depletion choline levels in brain
- Cholinergic deficit more pronounced DLB than in AD
- Cholinergic deficit early in disease
- Cholinergic depletion factor in symptoms early DLB
- Reduced alertness and attention, visual hallucinations
- Increasing ACTh levels - acetylcholinesterase inhibitors (pharmacological treatment)
- can have positive effects on symptoms
Neuropathology
- Dopamine deficiency:
- Genetics:
- Dopamine deficiency
- LB in substantia nigra
- Loss of dopamine receptors
- Available dopamine has less impact
- Weak response to dopaminergic drugs
- Genetics:
- No specific genes identified

Neuroimaging (DLB):
- Atrophy:
- atrophy in dorsal midbrain, striatum and hypothalamus
- little atrophy in hippocampus
- (so different than early AD)
- generally lower areas of the brain
- overall less atrophy than in AD or FTD
- Not different from HC (healthy older people)
Clinical features
- In addition to progressive cognitive decline:
- Parkinsonism
- Visual hallucinations
- Fluctuations cognitive functioning and arousal
Parkinsonism in DLB patients:
Parkinsonism:
- in 70 – 100% of patients with DLB
- rigidity, bradykinesia, shuffling gait, stooped posture, masked face
- tremor less common
- severity varies
- usually less severe in DLB than in PD
- patients may report frequent unexplained falls
- Parkinsonism must be spontaneous, i.e. not attributable to medication.
Dementia with Lewy bodies
- Visual hallucinations (VH)
- VH can occur in AD
- relative onset of VH
Visual hallucinations
- Fully formed detailed objects, people or animals.
- Auditory, tactile, olfactory hallucinations less common
- 22-89% of cases DLB
- DLB with VH typically more severe cognitive and functional impairments
- Visuospatial functions (Mosimann et al., 2004)
- More LB in temporal lobe
- VH can occur in AD
- 11-28% of cases
- VH onset from onset cognitive impairments
- DLB: 1.5-2 years after onset (so quite early), sometimes even before onset cognitive impairments
- AD: 5 – 7 years after onset
- Distinction useful differential diagnosis AD en DLB

Dementia with Lewy bodies
- Fluctuations in cognitive functioning and arousal
- Ferman et al. (2004): fluctuation questionnaire completed by informants
Fluctuations in cognitive functioning and arousal
- Fluctuations in attention, incoherent speech, impaired awareness of surroundings, staring into space, “switched off”
- Reported prevalence: 10% to 80%
Ferman et al. (2004): fluctuation questionnaire completed by informants
- Items best distinguished DLB from AD and HC:
1. Daytime drowsiness and lethargy
2. Daytime sleep 2 hrs or more.
3. Staring into space for long periods
4. Flow of ideas seems unclear, disorganised, not logical - 3 or 4 feature present 63% DLB patients (n=70), 12% AD patients (n=70), 0.5% normal elderly (n=200).
- not all DLB patients had fluctuations
- presence of fluctuations not associated with parkinsonism
- different underlying causes
Picture: White columns: normal elderly; Grey Columns: AD; Black Columns: DLB. Numbers according to items previously mentioned.

Distribution clinical features in DLB
- Clinical features overlap in DLB and AD
- from: Ferman et al. (2006)
- Percentage of patients with symptoms DLB N=89
- hence these core features might be good indicators to differentiate between AD and DLB
- 73% of AD’s had none of these core features, none had all three of them
Further clinical feature: core feature according to Smith & Bondi (2013)
- Sleep disorders:
- early indicator for DLB?
- Sleep disorders
- 70 to 75% of DLB cases
- in particular REM Sleep Behavior Disorder – RBD
- loss of muscle atonia during REM sleep
- movements during REM sleep
- Result: one might act out dreams
- RBD can be early sign DLB, precede cognitive impairment by several years
- Presence of RBD is risk factor:
- 12-year risk 52% (Postuma et al., 2009)
- case of confirmed DLB after 20 years of RBD.
- Presence of RBD is risk factor:
- Poor sleep quality also common
- Can contribute to excessive daytime sleepiness
Differential Diagnosis DLB:
- Probable DLB: presence dementia plus at least 2 core features
- Possible DLB: presence dementia plus 1 out of 3 core features
- Suggestive features support diagnosis
- Counter indicators: evidence CVD or other physical or brain disorder
Central and core features of possible and probable DLB (diagnosis):

Suggestive features for for possible and probable DLB (diagnosis)

Counterindicators for DLB (Diagnosis):

Diagnosis
- Temporal sequence important for diagnosis:
Temporal sequence important for diagnosis:
- DLB: dementia before or at same time as parkinsonism (e.g. motor-symptoms)
- Parkinson dementia: dementia when Parkinson symptoms already obvious
- Parkinson’s disease dementia (PDD): 3-5% dementia cases
Neuropsychology of DLB:
- Impairments in visual perceptual skills, attention, EF and fluency
- Memory impairments less prominent than in AD
- Overlap symptoms DLB and AD: misdiagnosis common.
- Search neuropsychological profiles
Neuropsychology of DLB:
- Visuospatial abilities
- Calderon et al., 2001
- 9 probable AD patients, 10 probable DLB patients, 17 HC
- Tests of visuospatial abilities/perception memory and attention/EF
- Pronounced deficits in visuospatial abilities/perception compared to HC and AD
Neuropsychology of DLB
- Memory
- Episodic memory less impaired in DLB than in AD
- autopsy-confirmed DLB (n=24), autopsy-confirmed AD (n=24) and HC (n=24) (Hamilton et al. 2004)
- Difference DLB – AD retention and recognition episodic memory
- patients with DLB were less impaired compared with AD but worse than HC
- No difference DLB and AD learning and immediate recall
- Difference DLB – AD retention and recognition episodic memory
- Memory deficits early stage DLB usually mild (milder than AD)
- little atrophy hippocampus
Neuropsychology
- Executive functions/attention
Executive functions/attention
- DLB and AD (based on clinical diagnosis) and matched HC
- Stroop (COWAT) and TMT B poorer in DLB than HC and AD
Neuropsychology
- Language
Language
- Boston naming test
- Ferman et al. (2006): DLB > AD, DLB < HC
- Hamilton et al. (2004): no difference DLB - AD
- Calderon et al (2001): no difference DLB - AD

Neuropsychology
- Meta-analysis neuropsychological differences DLB and AD (Gurnani & Gavett, 2017) –
- 14 studies included autopsy confirmed DLB (n=155) or AD (n=431)
- AD memory worse
- DLB visuospatial worse
- No differences attention, processing speed, EF, language
Neuropsychology
- Neuropsychological pattern similar in DLB and PDD
- (Troster & Browner, 2013)
Neuropsychological pattern similar in DLB and PDD (parkinson’s disease dementia)
- EF (e.g. Stroop, TMT WCST) and attention impaired
- Memory - impairment similar severity
- Language - naming relatively spared
- Visuospatial abilities – impaired, more severe than in AD
Neuropsychiatric symptoms (DLB)
- Hallucinations and delusions
- Similar prevalence in DLB and PDD
- Can occur several times/day
- More frequent in night or evening
- Delusions of misidentification (Capgras), theft, infidelity
- Depression
- Common all forms dementia, possibly more common DLB than AD
- Apathy
- Anxiety
Early symptoms/prodromal DLB:
- aMCI or naMCI
- latter more common
- Transient disturbances consciousness
- Visual hallucinations
- RBD
- ± 50% DLB cases prior cognitive decline
- Parkinsonism
- Hyposmia (reduced sense of smell)
- one of the areas were LB are found is in the Olfactory Bulb
Treatment DLB
- Pharmacological
- Non-pharmacological
Pharmacological
- No cure, some symptoms treated with medication.
- Levadopa/L-dopa for motor functions/parkinsonism
- Acetylcholinesterase inhibitors - cognition
- Oversensitivity neuroleptic medication
- used to treat hallucinations or agitation
- can severely worsen motor and cognitivempairments in DLB
Non-pharmacological
- Often supporting the family caregiver
- Educate family to cope with behaviour
- e.g. “go along”, give reassurance, instead of trying to reason with the patient
- if hallucinations are not distressing or harmful to the patient, why correct them
- unsuccessful and distressing