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Flashcards in Week 236 - Dementia Deck (42)

Name at least two other types / causes of dementia besides Alzheimer's and Vascular?

Lewy Body Dementia (DLBT) or Parkinson's dementia
Fronto-temporal e.g. Pick's

Also rarer forms e.g. Huntington's dementia, CJD, HIV and alcohol


What is the main difference between Parkinson's dementia and Lewy Body dementia (both Parkinson's related dementia)?

Parkinson's dementia: prominent motor features which pre-date dementia by at least 6months
Lewy Body dementia: mild motor symptoms, onset of cognitive and motor Sx similar (time-wise)


How does Alzheimer's Disease present?

Insidiously with gradual deterioration


What neuropathic changes occur typically in AD?

- Formation of neurofibrillary tangles and amyloid plaques
- Cholinergic transmission deficit


What changes are you likely to see in a CT head of a patient with Alzheimer's Disease?

Widening of sulci
Enlargement of ventricles
Atrophy / shrinking of brain


What are the risk factors for Alzheimer's?

Female gender
Head injury
Environmental e.g. Oxidative stress


What are the two most common forms of dementia?

Alzheimer's Diease followed by Vascular Dementia
(Common to have a mixed diagnosis of the two)


How does vascular dementia present?

Sudden onset
Stepwise deterioration
Mood/behaviour changes
Insight preserved


What neuropathological changes occur in Vascular Dementia?

Single or multiple thrombotic or embolism enfarcts
Small vessel disease


What are the risk factors for vascular dementia?

High cholesterol
Male gender


How does Lewy Body Dementia (DLB) present?

Fluctuating cognition
Vivid visual hallucinations
Mild Parkinsonian features
Repeated falls
Memory loss (may not be marked early in disease!)


What neuropathological changes are seen in DLB?

Lewy Bodies: abnormal aggregate of protein (synuclein fibrils) develop inside nerve cells
a) Classical - brainstem: round, brown, eosinophilic cytoplasmic inclusion with halo of radiating fibrils
b) Cortical: still made of alpha-synuclein fibrils but lacks halo


How does Fronto-temporal Dementia (such as Pick's Disease) present?

Apathy; reduced motivation; self-neglect
Disinhibition; reduced social awareness, lack of judgement
Personality changes and social inappropriateness
Memory loss is variable but language difficulties are prominent
More common in men, with onset


What are the main differentials for dementia?

Secondary dementia due to underlying illness
Mild cognitive impairment (MCI)
Acute confusional state / delirium


What is the prevalence of mod/severe dementia >65 and >80 in the UK?

>65 = 5%
>80 = 20%


What are the three key features of dementia?

1) Global impairment of higher cortical function
2) Occurring in clear consciousness
3) Progressive and present for >6 months


What five main areas of cognition are important to assess according to the ICD 10 Diagnostic Criteria?

Executive functioning (abstract thinking, judgement, reasoning)
Motor skills (Praxis)
Language (expressive and receptive)
Gnosis (ability to recognise objects, faces, sensory information)


What is the key difference between dementia and MCI?

Dementia: global impairment of intellect, memory and personality resulting in impaired performance in activities of daily living

MCI: cognitive decline >expected for age and edu level but does not notably interfere with activities of daily living


What pharmacological options should be considered for Alzheimer type dementia and Lewy Body dementia ?

- Mild-Mod consider anti-cholinesterase meds
- Mod-Advanced consider Memantine (NMDA antagonist)


What treatment options should be considered for Vascular Dementia?

Consider: low dose aspirin; statin
Appropriate BP and blood glucose management
Life-style advice re smoking, low fat diet


Name 3 anti-cholinesterases

Aricept - Donepezil
Exelon - Rivastigmine
Reminyl - Galantamine


How do anti-cholinesterases work?

Increase concentration of acetylcholine (neurotransmitter) at synaptic cleft by reducing aceytylcholine breakdown


How do NMDA antagonists work? (E.g. Memantine)

Blocks the effects of pathologically high levels of glutamate by uncompetitively binding to NMDA receptors (on which glutamate acts a remember glutamate is the major excitatory neurotransmitter in the CNS)


Name 3 genes associated with early onset Alzheimer's Disease

Presenilin 1 and Presenilin 2
Beta amyloid precursor protein gene (APP)


On which chromosome is each of the 3 genes assoc with Early onset AD found?

Presenilin 1 - Ch 14
Presenilin 2 - Ch 1
APP - Ch 21


Which gene is associated with late onset AD (onset >65) and on which chromosome is it found?

Apolipoprotein E gene (apoE4) found on Ch 19


Why would antidementia meds not be worthwhile prescribing in Parkinson's Dementia?

Because they act on either blocking NMDA receptors on neurones (Memantine) or increasing acetylcholine availability in the synaptic cleft (acetylcholinesterase inhibitors such as Aricept (Donepezil))
Parkinson's 'Dementia' is caused by a lack of dopamine production in the substantia nigra so levodopa +/- carbidopa is the correct treatment


What are the 4 primary symptoms that occur as a result of dopamine in Parkinson's?

Tremor (trembling arms, legs, face, jaw)
Slow movement AKA Bradykinesia
Postural instability (impaired balance and co-ordination)


What is declarative memory?

AKA "explicit" memory - the long-term retention of facts and concepts (semantic) and events (episodic) that can be drawn upon when necessary


What is non-declarative memory?

The learned skills and activities that are committed to memory


What parts of the brain are associated with declarative memory?

Medial temporal lobe (hippocampus and hippocampal region)


What parts of the brain are associated with non-declarative memory?

Motor - cerebellum
Emotional conditioning - amygdala


What is retrograde amnesia?

A loss of memories before trauma or specific event


What is antegrade amnesia?

An inability to form new memories


What is Korsakoff syndrome and what commonly causes it?

A deficiency in Vit B1 (thiamine) due to inability to absorb it
Often due to chronic alcoholism
Causes irreversible damage to medial thalamus and mammillary bodies resulting in anteretrograde and retrograde amnesia


Damage to Brodmann's areas results in what? Where is it located?

'Neglect' of incoming sensory information
Posterior parietal area


Damage to the temporal cortex is associated with what?

Agnosia (non-knowledge or a loss of knowledge)


What does prosopagnosia mean?

The inability to recognise people from their faces


Damage to the frontal lobe is associated with what sorts of signs?

Inability to plan a sequence of events
Loss of flexibility in thought
Emotional lability (instability) / personality change
Passivity / apathy
Socially inappropriate behaviour Expressive aphasia


Explain the difference between aphasia and dysarthria

Aphasia is difficulty with naming objects (producing speech) and understanding speech as a result of brain damage

Dysarthria is difficulty with muscle movements within the face and tongue to form words and mediate speaking


Describe the effects of damage to Wernicke's area? Where is it located?

Temporal lobe (left in most)
Wernicke's aphasia results - unable to understand language
- able to form speech fluently but it makes no sense


Describe the effects of damage to Broca's area? Where is it located?

Frontal lobe (left in most)
Damage results in Broca's aphasia:
- able to understand language
- not able to construct own speech (result = disordered syntax and grammar, repetitive and halting speech)