w5: : Parkinson’s Disease Dementia, Dementia with Lewy bodies, and Huntington’s Disease Flashcards
Parkinson’s Disease Dementia, Dementia with Lewy bodies, and Huntington’s Disease
- All associated with frontal striatal network
- All related via the dopaminergic pathway – all involve this
- Subcortical dementia – limited sight, but originate in subcortical area
- All have prominent motor system’s – in contrast with Alzheimer’s, frontal dementia and all
Lewy Body Diseases
we find lewy bodies within the brain
**lewy body diseases **= parkinsons, parkinsons w dementia, dementia with lewy bodies.
lewy body dementias: parkinson’s w dementia, dementia w lewy bodies.
Lewy Bodies
Neuronal inclusions:
- Protein: ubiquitin and alpha-synuclein
Typically found in all subcortical nuclei
- Substantia nigra
Regional distribution can vary between people with lewy body disease
- Correlating with the symptomatology
Pathology differs strongly from the pathology of Alzheimer’s disease.
Lewy Body Disease
Parkinson’s disease
First described by James Parkinsons in 1817
- A disease of the central nervous system
- Progressive, neurodegenerative disease
- Caused by death of dopaminergic neurons in the substantia nigra.
results in movement disorder, PET scan for diagnosis
- The striatum is involved.
- Subcortical area
- Connected to frontal cortex- important for both movement and cognitive functioning.
Parkinson’s summed yp
- The cells in the substantia nigra degenerate
- Consequence: a decreased amount of dopamine
- Results: dysfunction striatum
- Dysfunction of the areas connected to the striatum
- Whole network starts to not work
Parkinson’s Clinical Presentation
Motor symptoms
- Tremor- rest tremor, in hands, legs. Person is sitting and having a tremor. Not present in action typically
- Rigidity – can only feel, resistance in the limb
- Bradykinesia- slowness of movement
- Postural instability- people are easily out of balance
^^ at least 2 of these have to be present to diagnose
Clinical appearance
- Difficulties doing things we do automatically !!
Ie.
Walking
Rising from a chair
Tunring around in bed
Keeping balance
Monotone speech
Drooling
^^cannot control automatic motor movements and control
Parkinson’s Neuropsychiatric symptoms
depression
apathy
anhedonis
visual hallucinations- later stages
impulse dusorders - due to medication
- Dopamine also important for reward system, too much can cause impulse disorders- ie. Gambling, too much eating
Parkinson’s + Cognitive Impariments
24% of ppl w Parkinsons already have cognitive impairment
- MCI w parkinsons.
- parkinsons w dementia
- Progress over time
- If they progress then could get mild cognitive impairment In context of parkinsons
- And if it progress even more = parkinsons dementia
- Information is processed slower, slower thinking = psychomotor symptoms
- Language = not aphasia! Complex sentences might be difficult to understand or speak
- Memory
main issues:
psychomotor speed
visuospatial skills
attention and executive functions
affected but less so:
- language
- memory
issues with attention and executive function due to striatum being involved–> connected to frontal cortex
Lewy Body Dementia
Parkinson’s dementia- Dementia
- 50% of people with parkinsons develop parkinsons dementia
- People with parkinsons mainly shor degeneration of attention and psychomotor speed
Risk factors of dementia:
- Higher age
- Visuoconstructive dysfunctions
- Hallucinations visual
- Impaired semantic verbal fluence – name as many animals as possible in one minute
Parkinson’s Disease Dementia- diagnostic criteria
A. the disturbance occurs in setting of established parkinsons
B. there is insidious onset and gradual progression of cognitive impairments
C. disorder not attributable to toher medical condition/ medicine
D. impairments have negative influence on functioning
E. impairments are present in at least two of the following:
- memory
- attention
- executive function
- visuospatial functions
the presence of one of the following behavioural disorders makes diagnosis more likely
- visual hallucinatios
- agitation
- excessive daytime sleepiness
- depression
- anxiety
- apathy
Dementia with Lewy Bodies
Pathological Cause and Progression
Key Feature: Early accumulation of Lewy bodies in cortical areas
.
Progression: Cognitive decline appears first, with motor symptoms developing later
Onset and Symtoms DLB
Onset: Cognitive symptoms precede or occur within 12 months of motor symptoms
.
Symptoms:
Fluctuations in attention/alertness.
Vivid visual hallucinations.
REM sleep behaviour disorder.
Parkinsonism
Dementia w Lewy Bodies DSM-5
A. criteria met for major or mild neurocognitive disorder
B. disorder has insisius onset + gredual progression
B. meets combination of core diagnostic features and suggestive features for lewy bodies disoder.
C. not better explained by something else
core symptoms:
- fluctuating allertness/attention
- vivid hallucinations
- parkinsoniskm- onset subsequent cognitive decline
suggestive symptoms:
REM sleep disorder
neuroleptic sensitivity
Central Features DLB
progressive cognitive decline that interferes w normal functioning
impairments in:
- memory - not as bad as alzh
- visuospatial functions
- executive functions
- attention
differentiation from alzh
more severe effects in:
- attention
- verbal fluency
- visuospatial ability
- executive functions
- psychomotor speed
^^ all relate to frontal cortex functions
**mini mental state exam ** NOT valid for lewy bodies- too fosued on memory
PDD vs Alzh
- More cortical disorders, such as aphasia, apraxiam agnosia are not common in people with parkinsons disease dementia
- People with parkinsons disease dementia mainly have impairments in retrieving information from memory – recognising is intact, extrernal cues have a positive effect.
Visuospatial impairments are more often present in people with parkinsons dementia- perceiving the world around you, how objects related to each other, identifying objects
Little cortical atrophy (what happens in alzh)
More fronto-parietal hypometabolism
Alzh vs DLB
memory issues aren’t as pronounced as Alzh.
mini mental health examination not sensitive for DLB - too memory focused
in DLB- memory fails at retrieval stage compared to failure of storage in alzh
- intact performance on recognition tasks
rate of progression slightly fasterin ppl w DLB compared to alzh.
DLB- prominent visuospatial dysfunction, seen in copy drawring tasks, ie. of a clock
Core + Suggestive Features DLB
fluctuations cognition, parkinsonism, neuropsychiatric, REM
Core features: Fluctuation in cognition + allertness
- prominent symptom
- can occur rapifly or over weeks
- difficult to indentify due to range in fluctuations
- use same test twice during assessment- compare if significant difference in scores b/w
core feature: parkinsonism
- motor symptoms
- 45-100% w DLB have it
- mirror parkinsons
- rest tremor less prominent
- ridgidity and bradykinesia is present in both
-Postural stability, hypomimia and gait difficulties - more in DLB
AFTER cognitive symptoms
core feature: neuropsychiatric
- 80% have hallucinations
- occur early typically
- vivid, colourful, often not scary- don’t realise its not real
- apathy, anxiety, depression, MAINLY visual hallucinations
Suggestive: REM disorder
- normal atonia of REM does not occur
- result: movement, vigorous, during REM - as if acting out dream
- REM sleep disorder is typical of DLB
- REM disorder can occur before dementia- risk factor
suggestive: severe neuroleptic sensitivity
- neuroleptics are prescribed to treat psychoses (clozapie or haldol)
- side effects of neuroleptics: drowsiness, parkinsonism, falls)
side effects can occur to any person w dementia but are more prominent in peorple with a dementia w lewy bodies
DLB vs PDD
reduced dopaminergic transmission: no difference b/w PDD and DLB
DLB, PDD- strong overlap in regard to
- pathology
- symptoms
particular apparent in later stages - bc in later stages both have cogntiive impariemnts and parkinsonism
DLB + PDD = descriptive labels for the course of symptoms
Hungtington’s Disease
progressive, hreditary disease w insidious onset.
characterised by:
- motor symptoms
- cognitive impairments
- neuropsychiatric symptoms
^^ may lead to dementia
Genetic Basis Huntington
1993: Huntington caused by CAG repeat on short arm chromosome 4
healthy: <36 repeats
36-39 repeats- mild symptoms can remain healthy until old age
40+ : indiv develops hungtington
autosomal dominant disease
Pathology Huntington:
Huntington gene –> changed function of huntingtine protein = degeneration certain parts of brain
early stages: degeneration of striatum = dysfunction of fronto-striatal circuits
–> changes dopaminergic transmission systems (decreased receptor binding)
Late stages of disease: global atrophy of brain
not strictcly movement disorder, has cogntive decline too
Hungtington Motor Symptoms
Dysikinesias
-** chorea**- increase in random movements, uncontrolled
- hypokinesia- decrease number spontaneous movements
bradykinesia- slowness of movement
dystonia- sustained muscle contractions
ridgidity
dysarthria
problems with eye movements
problems with swallowing
problems with keeping balance
chorea most striking symptom
Hungtington cognitive symptoms
progressive decline cognitive functioning differst b/w ppl.
- relatively mild until later
OR
- fast progression, dementia early
Impairments particularly present:
- psychomotor speed
- executive functions
- attention
- memory - in retrieval
Hungtington - Memory dysf
impairments in:
- encoding and retrival of information - recongition and kowledge of general facts are relativelly intact
working memory
- early stages memory impairments can be due to executive function and attention impairments
Hunginton - Psychomotor speed
slowness of thinking- bradyphrenia
slowness in acting
slowness is not caused by motor symptoms
Hungtington cogntition-
close to onset, late stages
close to onset: impairments in memory, executive functions, attention, psychomotor speed are prsent in some but NOT ALL
early and later stages: majority pf ppl show impairments in memory, executive functions, attention, and psychomotor speed
Hungtington disease insight
ppl w Hungtington rarely compain about motor symptoms + cogntive impairments.
due to:
- lack of insight as a consequence of cognitive dysfunction
- psychological protection mechanism
Hungtington- Neuropsychiatry
large indiv differences.
affective disorders:
- depression- consequence of pathophysiological changes
- anxiety- insecure ab future
- apathy- middle/ late stages of disease
- agitation- one of first symptoms
- disinhibition- no self control related to eating, drinking, speaking or sexuality
- compulsive behaviour- obsessive and compulsive thoughts or acts
- psychoses- hallucinations or delusions
Hungtington Summary
progressive, hereditary disease w insidious onset
- CAG repeat on chromosome 4
characterised by degeneration of the striatum and dysfunction of fronto-striatal circuits
Treatments/ Interventions Hungtington
Pharmacological Treatments
1. Tetrabenazine:
o Reduces chorea (involuntary movements).
o Side Effect: May increase depression risk.
2. SSRIs:
o Effective for managing irritability and depressive symptoms.
Non-Pharmacological Interventions
1. Assistive Technology for Cognition (ATC):
o Tools (e.g., planners, memory aids) to address cognitive inefficiencies.
o Mixed evidence for improving quality of life.
2. Cognitive and Physical Interventions:
o Rhythm exercises: Improve executive functions and white matter integrity.
o Multidisciplinary programs: Combine physical and cognitive exercises to enhance brain volume and verbal learning.
o Need for randomized controlled trials (RCTs) to confirm efficacy.
3. Behavioral Interventions:
o Encourage participation in structured, pleasurable activities.
o Manage irritability through identifying triggers and educating caregivers.
