Lecture 7 - Biology & Cognitive Disability Flashcards
What are the 2 branches of cognitive disabilities?
- Genetic/ Pre-birth cognitive disabilities
2 Developmental Cognitive Disabilities
Outline Genetic/ Pre-birth Cognitive disabilities
These are cognitive disabilites caused due to the malformation of the genes you inherit
- this can be caused by things going wrong in the womb, e.g. illness/ viruses
Examples: - Down Syndrome - Fragile X Syndrome - Ceberal palsy - but 1/3 wont have any cognitive defects •You are born with all these
Potentials:
•Tourettes - unclear cause
•Epilepsy - unclear cause that can impact cognitiosn
Outline down syndrome as an example of a cognitive/ pre-birth disability
- Caused by one of your inherited genes doubling - meaning you have a 47th Gene
- 50% chance of passing it on
- 1 in 1000 born every year
- Reduces mortality, to an average age of 47
- Characteristics:
- facial features
- lower IQ
- Delayed in reaching developmental milestones (walking, speech, language etc)
X - is it ethical to find out if your child has it?
What is meant by developmental cognitive disabilities?
- You acquire them later in life, not pre-birth
- If you Develop atypically - youCannot diagnose them until they fail to reach developmental milestones (e.g. walking, speech, language)
Examples:
•ADHD
•Dyspraxia - odd muscle movements, uncontrolled
Potentials:
•ASD - debate about what actually causes it. Is it an ASD gene? No ones found one
- is it parental upbringing/ infantile virus
X - are the causes actually genetics though?
Outline ASD as a developmental cognitive disabiltiy
•It’s on a spectrum ranging from mild to profound
•Symptoms:
- Difficulties with communication (profound might not even be able to talk)
- Repetitive routines, narrow interests, inflexible preferences
•1 in 1000
- more common in males
X - why are numbers increasing, especially with males
- is prevelance increasing
- or are we screening more?
What are the 5 Causes of developmental cognitive disability
Similar to Causes of Broca’s:
- Head injury
- Brain Tumour (younger, healthier are less at risk)
- Stroke (younger, healthier are less at risk)
- Viral infection (unlikely for a young person to get this - could cause Az
- Toxins - drugs, alcohol etc - can kill brain cells
Could lead to problems with: language, reasoning, perception and mental faculties
Outline the first cause of developmental cognitive disabilities: 1. head injury
Head injuries have a wide variation in severity
- Head injury is most common cause of death/ disability in 0-40 year olds
- 0-4 are most common to visit A&E for TBI
- 15-24 are next more common
Can have closed head injury
Outline closed head injury as part of head injuries as a cause for developmental cognitive abilities
Stuff when there is predominantly internal damage - not necessarily any blood or anything
- such as concussion
For instance in a car crash, our brains are in fluid, when we jolt forward - our frontal lobes hit the front of the skull. We then recoil backwards, our occipital lobes then hit the back of the skull
- Causes double damage:
•Vision (Occipital damage)
•Reasoning (Frontal Damage)
individual differences in how we recover from closed head injury/ concussions
- for instance some will recover in weeks/ months, some will take longer
- Depends on the severity of the injury
- also factors like: female, younger, previous concussions - make it longer to recover
Outline A. R. Luria
- the man with a shattered world
Wrote a book called the Man with a shattered world (1987)
- talks about the patient Zasetsky who had shrapnel in his brain - the occipito-parietal lobe, after the Battle of Smolensk
- Luria documented his progression and his symptoms over time and then intensively treated him. Finding that he had:
- Disorientation: couldn’t recognise words, objects, places, directions
- Physically able, but couldn’t move due to his brain damage - i.e. nothing wrong with muscles/ joints
- All but very oldest memories were lost - was unaware he was in a war, and what regiment he was
- Frontal lobes were okay - could reason, problem solve etc. He had consciousness
- he was aware that he couldn’t remember
AFTER 25 YEARS
- Because it was a localised injury, Luria predicted he could use other pathways in the brain to regain the lost functions
- after 25 years of intensive rehabilitation - he regained his memories and his abilities to function as a social person - so much so that he wrote his own autobiography
What was the timeline of Zasetsky - the man with the shattered world
- Initially was completely cognitively disabled
- With rehabilitation he regained functions slowly
- Could eventually write his experiences up into a book
Outline the second cause of developmental cognitive disabilities: Brain Tumours
Two forms: Benign or malign
- Malign (Cancerous) - infiltration of cancer into brain tissue
- Banign (Will stop) - Compresses healthy tissue, pressurises surrounding neurons
- if it grows this can cause lots of problems: painful, and headaches etc
- Can pressurise the meniges - headaches
- Densley packs and compresses neurons to the point where it kills them
- could be pushing them out against the skull
Outline the third cause of developmental cognitive disabilities: Stroke
It is the most common cause of adult acquired disability - can be fatal if not treated quick enough
Strokes = interfer’s with brains blood supply in some way
- starves neurons of oxygen
- without which it will die.
2 Causes:
- Haemorrhage (caused by an aneurism bursting)
- too much blood in the wrong place - Blood clot cuts off blood supply
- too little blood
What are the symptoms of stroke
F.A.S.T - Fatal if not treated fast enough
- Face droops to one side
- Arms - at least one will sag, cannot lift both
- Speech becomes slurred
- Time to call - quicker they get attention the more favourable the consequences
Symptoms & Signs: •Confusion •Unsteadiness •Movement problems •Slurred speech •Emotionality - agitated/ angry
Not always fatal but in top 3 causes of death
- if its so big, nothing you can do, brain cant cope and dies
Outline the first cause of stroke: Haemorrhage
- If there is a weakness in the wall of the artery, it can’t cope with the pressure of the blood - so it balloons out
- but because it’s made from a weakness in the artery, this aneurysm is really thin and could burt - If it does burst, this gets into the brain and the CSF - this stops the neurons chemical communication
- interupts chemical balance between inside and outisde - They cant communicate with anything, including the heart and lungs, so neurons are starved of oxygen and die
Outline the second cause of stroke: Blood clot
If a blood vessel is blocked, it can cause a stroke
THIS IS CALLED: ISCHAEMIA
Blood cannot flow from the heart to the brain, via the common carotid artery