Dementia Flashcards
What are the types of dementia?
- Alzheimer’s: Most common, genetic predisposition (inc T21), advancing age, insidious onset, progressive slow decline, often co-exists with other forms (vascular)
- Vascular: 2nd most common, Executive function (planning) affected more than memory, damage to grey & white matter by vascular causes
- Lewy body: 3rd most common, Cognitive decline w/combination of day to day fluctuating cognition
- Fronto-temporal: 2nd most common in <65yo, 3subtypes: Behavioural-variant, semantic, progressive non-fluent aphasia
How is dementia defined?
A progressive neurodegenerative condition with acquired loss of higher mental function affecting >2 cognitive domains:
- Episodic memory/ decline in memory & thinking
- Language function
- Visuospatial function
- Apraxia/agnosia
How is dementia diagnosed?
> 6month duration of symptoms & must be impairment in person’s activities of daily living
What are the causes of dementia?
Degenerative
Vascular causes
Trauma
Neoplasm
Toxic: OH-, CO, cyanide, arsenic, lead, mercury
Iatrogenic: antihistamines, anticholinergic
Inflammatory: Lupus, sjorgren’s, encephalitis
Infectious: CJD, Lyme disease, prion, neurosyphilis
What is the pathophysiology of Alzheimer’s?
Reduced brain weight
Senile plaques & neurofibrillary tangles & neuronal loss
Global Cortical atrophy
Extracellular plaques made up of beta-amyloid
Intracellular tangles made of cytoskeletal filaments
In Alzheimer’s, what is the number of tangles associated with?
The severity of the disease & cognitive decline
What is the pathophysiology of vascular dementia?
Ischaemic disorder
Infarction: Multiple small/large infarcts affecting cortex & white matter
>100mL of infarct = clinical symptoms
Exhaust brains compensatory mechanism= dementia
Haemorrhage: Large parenchymal haemorrhages centered in the basal ganglia
What is the pathophysiology of Lewy body dementia?
Accumulation of lewy bodies in vulnerable sites (cerebral cortex)
Mimics parkinson’s disease
Cytoplasm in neutron has abnormalities: Composed of ubiquitin, neurofilaments & alpha-synuclein
What are the symptoms of vascular dementia?
Begins in 60s Motor Mood changes EARLY Hx of strokes Stepwise Dec cognitive function/ Difficult solving problems Apathy Disinhibition Slowed processing of info Poor attention Nocturnal confusion Behavioural & psychological signs
What are the symptoms of Alzheimer’s?
5A's- Amnesia Aphasia/Anomia Agnosia Apraxia (doing) Associated behaviours (Behavioural and psychological symptoms of dementia): Personality changes, labile mood, paranoia, parkinsonism
What are the symptoms of Lewy body dementia?
Visual hallucinations
Antipsychotic sensitivity
Prominent dysexecutive syndrome
Visuoperceptive disturbances
Parkinsonism: Tremor, hypokinesia, rigidity, postural instability
Transient LOC
sometimes: REM disorder, neuroleptic sensitivity, depressive episode, Rx falls
What are the signs of dementia?
Anosognosia: Downplays or denies symptoms
Head-turning sign: Constantly looking at relative for answers
Frontal release sign: Primitive reflexes, grasp
How is dementia investigated?
Bloods: Rule out organic causes
CT/MRI
Cognitive assessment: MMSE, AMTS, MoCa
What are the 5 brain changes seen in dementia?
CT/MRI:
1) Cerebral atrophy (medial temporal lobe atrophy)
2) Senile plaques
3) Amyloid deposition
4) Neuro-fibrillary tangles
5) ↓Acetylcholine levels
How is dementia managed?
Dementia: Supportive
General (High dose VitB)
Cognitive enhancers
Cholinesterase inhibitors (Donepezil, Rivastigmine-patch)
Memantine (NMDA receptor antagonist)
Trial of antidepressants (Sertraline, Citalopram)
Antipsychotics (Risperidone, Olanzapine)
Alzheimer’s: Acetylcholinesterase inhibitors, NMDA receptor antagonist, Carers, OT, Social care, cognitive rehabilitation
Lewy body: DO NOT give antipsychotics (60% worsened EP signs)
