Neurobiology of Cognition Flashcards
What functions are thought to be specific to the mind rather than the brain?
Higher level thinking:
- memory
- judgement
- social communication
What is Mind-Body dualism?
Philosophical view that mind/mental phenomena are non-physical
OR that mind and body are distinct and separable.
What is meant by substance dualism?
Philosophical view that two sorts of substances exist: the mental and the physical.
What is known as semantic memory?
Remembering factual information
What test can be completed to check that patients with Dementia still have the cognitive ability to drive?
Divided Attention Test
What part of driving do patients with dementia often struggle with?
Unfamiliar situations
=> procedural memory is usually intact, but they have difficulty reacting when presented with something they weren’t expecting
How did Aristotle first describe a memory?
Holding a perceived experience in mind and recognising that you have seen it externally in the past (i.e. it is not an internal thought)
What did Galen propose about the brain?
That it was the source of mental activity
Most functions are coordinated by multiple areas of the brain. TRUE/FALSE?
TRUE
Where is Broca’s area located?
Posterior inferior frontal gyrus
What does a lesion in Broca’s area cause?
Broca’s dysphasia - Patient an comprehend others but has difficulty forming words and fluent speech
Where is Wernicke’s area located?
Superior Temporal gyrus
What does a lesion in Wernicke’s Area cause?
Receptive dysphasia
=> patient can comprehend language
=> speech is fluent, but often does not make much sense as they do not understand what they are saying
What are Brodmann’s Areas and in which area is the Primary Motor Cortex located?
cerebral cortex classified into areas by its cyto-architecture
i.e. histological structure and cellular organisation
Primary Motor Cortex = Brodmann’s Area 4
What scan can be used to identify which areas increase in activity during certain tasks?
Functional MRI
- shows increase in blood flow in certain areas
Briefly explain the multi-store model of memory
Sensory memory -> pay attention to it -> Moves to Short term Memory -> Rehearsal -> Long term Memory
Retrieval of memory from long term to short term -> Recall
How long do memories remain in the short term memory for?
between 7 secs to 1 min
What part of the brain is responsible for encoding short term memory to become long term memory?
Hippocampus
What is the definition of dementia and what else is required for a diagnosis?
Progressive global cognitive decline
IRREVERSIBLE
- must also be at least mild functional impairment present for diagnosis
If patients have a diagnosis of mild dementia and still wish to carry on with work as normal, what support can be put in place?
- Employment adjustments can be made if patient still has decent function
Where does Alzheimer’s usually begin in the brain?
Mediotemporal lobes (hence why memory is affected early)
What are the most common presenting symptoms of Alzheimer’s?
Most common - memory problems
May also have word finding difficulty
What 3 symptoms are indicative of Alzheimer’s dementia?
Dysphasia
Dyspraxia (lack of coordination)
Agnosia (difficulty identifying objects)
Name an end stage symptom of Alzheimer’s dementia
Loss of swallow
=> dysphagia
What is the average life expectancy after a diagnosis of Alzheimer’s?
7 years
What are the histological hallmarks of alzheimers dementia?
Amyloid plaques OUTSIDE of cells
Neurofibrillary Tangles INSIDE of cells
What forms the intracellular neurofibrillary tangles in Alzheimer’s dementia?
hyperpolarised Tau protein aggregation
Which of the two histological hallmarks of Alzheimer’s has a larger link to cognitive impairment?
Neurofibrillary tangles
What class of drugs is usually used to treat Alzheimer’s disease? Give examples of specific drugs in this class.
Cholinesteras inhibitors
=> prevents breakdown of ACh
=> more remains in synaptic cleft
e.g. Rivastigmine, Donepezil
Memantine is also used to treat Alzheimer’s Dementia. What class does this drug belong to and what does it aim to do?
- NMDA receptor antagonist
- Previously was only used in moderate -> severe Alzheimer’s, but now being started when in Mild -> Moderate phase
- Aims to prevent psychosis and other psychiatric symptoms from developing
How does Vascular dementia usually appear on a CT scan?
White matter hyperintensities visible
What is dyscalculia?
problems with maths/ understanding numbers that develops in certain types of dementia
What protein aggregates with Ubiquitin in Lewy Body Dementia?
Alpha-synuclein
What other neural pathology occurs in Lewy Body Dementia and what group of symptoms does this result in?
Loss of dopaminergic neurons in substantia nigra
=> Parkinsonism symptoms
What symptoms of Lewy Body dementia predispose to patients falling?
Fluctuating conscious level
Parkinsonism
Hypotension
Visuospatial problems
What drugs should be avoided to treat Lewy Body Dementia and why?
Dopamine agonists - e.g. SINIMET given in Parkinsons
- can caused marked abnormal behavioural symptoms
- can decrease cognition
What drugs are commonly used to treat Lewy Body Dementia?
Cholinesterase inhibitors
Anti-psychotics can also be useful
At what age does Fronto-temporal dementia normally start?
55-65 years
=> earlier than other dementias
What are the main symptoms of Fronto-temporal dementia?
Personality/ behaviour change
- patient becomes disinhibited and has a lack of interest in social acceptance
What symptoms are particularly noticeable in the behavioural variant of Fronto-temporal dementia?
Non-fluent aphasia - much like Broca’s dysphasia
Semantic Dementia - loss of factual understanding/ understanding of words
What is Wernicke’s encephalopathy?
Collection of neurological symptoms caused by a deficiency in Vitamin B1 Thiamine
What are the main 3 symptoms of Wernicke’s Encephalopathy
Ataxia
Confusion
Ophthalmoplegia
What other symptoms can patient with Wernicke’s Encephalopathy experience?
Visual OR Hearing impairment Reduced conscious level Hypothermia Lactic acidosis Circulatory changes
How is Thiamine replaced in Wernicke’s Encephalopathy?
Pabrinex infusion
What are the two most common causes of Wernicke’s Encephalopathy?
Overconsumption of Alcohol
Lack of thiamine in diet
What is Korsakoff’s syndrome and what causes it?
Atrophy of mammillary bodies in the brain (affecting memory)
Caused by leaving Wernicke’s Encephalopathy untreated
What symptoms do patients with Korsakoff’s syndrome experience?
Antegrade amnesia - inability to learn new information
Confabulation
Retrograde amnesia - forget events which happened in the past before condition began
Telescoping of events - perceive things as more recent than they were
What other forms of brain damage can be caused by alcohol?
Myelin sheath degradation
Neuroinflammation
Subdural Haematoma (if pt falls)
