NEURO 236 - Alzheimers Flashcards
What are the types and prevalence of dementia?
Alzheimers - 50+%
Vascular - 20-25
Lewy Body - 15-20
Fronto-temporal - 5-10
What are some differential diagnoses for dementia?
underlying physical illness, mild cognitive impairment, depression and an acute confusional state
What is the ICD10 diagnostic criteria for dementia?
acquired impairment in memory for at least 6/12
+ impairment in 1+ domains: executive functioning, language, praxis and gnosis with an interference with daily living
What is dementia?
global impairment of cognition and intellect with impaired performance of ADL’s
What is mild cognitive impairment?
cognitive decline greater than that expected at that age but no ADL interference
What is the presentation for alzheimers?
cognitive decline of an insidious onset and a gradual deterioration
What are some risk factors for alzheimers?
Age, female, genes, head injury, environmental factors
Where is amyloid precursor protein found?
integral membrane glycoprotein widely expressed but concentrated in neurone synapses
What is the neuropathology of Alzheimers?
Amyloid plaques - A-beta protein aggregating
Tau protein - neurofibrilliary tangles inside neurones due to tau hyperphosphorylation
glutamate excitotoxicity
= neurone loss and a cholinergic dysfunction
What is the presentation of vascular dementia?
sudden onset, step-wise deterioration, mood/behaviour change but preserved insight
What is the neuropathology of vascular dementia?
athersclerosis - small vessel disease
What is the presentation of lewy body dementia?
fluctuating cognition, vivid visual hallucinations, mild parkinsonian features
What is the management of alzheimers and lewy body dementia?
mild-moderate = anticholinesterase severe = memantine
What is the management of vascular dementia?
aspirin, statins and risk factor controls
Give some examples of anticholinesterases
donepezil, rivastigimine and galantamine
What is memantine?
An NMDA receptor antagonist
What other types of drugs can be used for symptom control?
anti-psychotics ( but take care they increase risk of death) e.g. risperidone short term only
try non -pharm first
ADM’s e.g. sertraline
night sedation
Where is acetylcholine made?
Basal forebrain
What is learning?
acquisition of new information
What is memory?
process by which learning is stored
What is working memory?
information is held whilst you work out what to do with it - 1st thing to go in AD
What is declarative memory?
memory of “stuff” - semantic (concepts) or episodic (autobiographal) - in the medial temporal lobe, hypothalamus and thalamus
What is non-declarative memory?
procedural memory, skills and habits (striatum), motor (cerebellum) and emotional condition (amygdala)
What is retrograde amnesia?
loss of memories from before the occurence of the trauma/event
What is anterograde amnesia?
Inability to form new declarative memories
What are Brodmans areas?
Found in the posterior parietal cortices they integrate visual, auditory and somatosensory information
What happens when there is damage to brodmans areas?
neglect - sensory from one side, neglect of body/world in contralateral space, denies affected side belongs to them and motor - fewer movements
What happens in temporal cortex damage?
agnosia
What happens in inferior temp cortex damage?
visual agnosia (see but not identify)
What happens in damage to the fusiform gyrus (TC)?
prosopagnosia - cant recognise faces
What happens in damage to mid tempo cortex?
cannot recognise stationary vs moving objects
What happens in frontal cortex damage?
loss of restraint, initiative and order
What is korsakoff syndrome?
irreversible damage to medial thalamus and mammilliary bodies as a result of thiamine deficiency due to chronic alcoholism = both amnesias and confabulation
What are parietal lobe lesions associated with?
apraxia - inability to perform a motor task at request
What does brocas area do?
making speech - frontal *what should I do
What does wernickes area do?
understand speech - what is it (temporal lobe)
What is aphasia?
speech disorder difficulty naming object and repetition
What do you see in Brocas aphasia?
an ability to understand speech but cannot make their own, halting and repetitive with disordered syntax and grammar
What do you see in Wernickes aphasia?
Unable to understand but has fluent speech just doesnt make any sense or have any relevance
What is the pathway that sensory information goes through the brain?
–> cortical association areas —> parahippocampal/hippocampas –> along fornix –> mamilliary bodies –> thalamus
