Brain damage and neurodegenerative disease Flashcards
What is congenital brain injury
Genetic factors, pre-natal, or birth related trauma
What is acquired brain trauma
Includes silly things we do to ourselves as a species
What are example of non-traumatic brain injuries?
Stroke, infection, tumours, hypoxia, anoxia. Often occurs inside skull with very little control over
What are the 2 causes of stroke?
Cerebral haemorrhage cerebral ischaemia
What is cerebral haemorrhage?
Burst of a blood vessel
What is cerebral ischaemia?
Caused by interruption of the blood supply to part of the brain due to blockage of blood vessel
What is a closed injury?
No penetration of the skull
What is dementia pugilistica?
Punch Drunk syndrome
Repeated powerful blows to the head are not conducive to long term brain health
Cumulative structural damage occurs resulting in dementia symptom
What is an open headed injury
Where the skull doesn’t remain intact
Describe the brain structure associated with Alzheimer’s disease
Diffuse changes in brain structure and volume associated with widespread neuronal loss
What are the type of symptoms of AD?
Predominantly cognitive symptoms in early stages
What neurotransmitter is associated with AD?
The loss of acetylcholine
What is the brain structure of PD?
Mainly attributable to a loss of a single type of neuron in a specific brain region
What type of symptoms associated with PD?
Predominantly but not entirely motor symptoms
What neurotransmitter is PD associated with?
The loss of the neurotransmitter dopamine
How much of the population is affected by PD?
Affects 0.5 percent of the population. 2.5X more common in men
What type of disease is PD?
An idiopathic disease
What are the symptoms of parkinsons?
Paucity of spontaneous movement (insufficiency of movement)
Bradykinesia (very slow movements)
Akinesia (no movements)
Resting tremor (@4.5Hz)
Shuffling gait and flexed posture, impaired balance
What is PD caused by?
Lack of dopamine in the nigrostriatal dopamine pathway found in the basal ganglia. Cells that release dopamine die off
Describe the heroin problem of the 80s
Development of new synthetic heroin led to spate of cases of individuals with pronounced parkinsonian symptoms
MTPT was an unwanted byproduct of the chemical process, that in the brain becomes converted to the highly neurotoxic MPP+
MTPT was found to be specifically targeting the dopamine producing cells of the substantia nigra
Describe the link between dopamine and motor system
Burst of dopamine disinhibits the motor system - doesn’t happen in PD
Talk about Levo Dopa
A dopamine precursor - replaces the lost dopamine - acts as treatment
Limitation - cells that release dopamine have died
Talk about DBS
Deep brain stimulation
Electrical stimulation of the basal ganglia - targets same sites as lesions but with electrical current tuned to shut them down
What is dementia
A chronic or persistent disorder of the mental processes caused by brain disease or injury and marked by memory disorders, personality changes and impaired reasoning
What is AD?
A disease that causes dementia
What are the symptoms of AD?
10% over 65 years old
45% of 85 years old
Memory loss
Selective decline in memory
Deficits in attention and personality changes
Intermediate stages; confusion, anxiety, irritability
Final stages; swallowing and bladder control
What is the assessment used for AD?
MMSE - mini mental state examination
Describe the neurons of someone who has Alzheimers
Includes neurofibrillary tangles and amyloid plaques
What are amyloid plaques
Aggregate lumps of amyloid proteins
Talk about the genetic risk factor of amyloid precursor protein
Found on chromosome 21
Downs syndrome - trisomy chromosome (150% of normal APP levels)
Describe genetic forms of AD
Appear to have an early onset
They are usually mutations in the APP gene
Talk about the genetic risk factor apoE
Apolipoprotein E
3 common alleles - E3, E4, E5
E4is bad and E2 is good
In the periphery it is involved in the transport of cholesterol
What are the sticks inside neurons called
Microtubules
What do microtubules do?
Part of the cytoskeleton - keeps a cells shape
What is tau?
A MAP - gets into a muddle and gets tangled up
What are microtubules formed from?
MAPs - microtubule associated proteins
What is acetylcholine important for?
Normal cognitive function, especially memory
What is AchE?
Cholinesterase - an enzyme that breaks down the neurotransmitter acetylcholine. In other words, prevents acetylcholine from continuing to act on the neurons. Inhibiting AchE increases the effect of acetylcholine on the neurons
What are the main drugs for AD?
Cholinesterase inhibitors
Donepezil hydrochloride (Aricept)
Rivatigmine (Exelon)
Galantamine (Reminyl)
