Flashcards in Neurological Disorders Deck (60):
Condition of low oxygen levels due to interuption of blood supply to the brain
What are the 2 types of stroke?
Blockage and Hemmorrhage
What are the 2 different types of Blockage?
Thrombosis - Build up of materials that block the blood vessels and doesn't move (so nothing can get through)
Embolism - Starts as thrombosis and breaks off and the build up of material moves with the circulatory system until it can't get past a smaller vessel - then it gets stuck there
What is the area of the brain that stops receiving blood?
What are the types of Hemorrhages?
What is a hemorrhage?
What is hemorrhages usually due to?
Hemorrhages are due to a ruptured blood vessel.
It is due to genetics and is a combination of Hypertension and structural defects in the arteries.
The defected genetics cause weak ass artery walls due to weak ass proteins- and hypertension pressures the artery walls.
What is aneurysm?
Like a balloon - Portion of the arterior walls that weaken Arteries are filled with blood that bulges and bursts.
Which of the 2 types of strokes are mainly due to genetics?
What would we treat aneurysms with?
What is the difference between the way hemorrhages are treated vs. blockages?
Hemorrhages - No blood thinner
Blockages - Blood thinners like aspirin
The difference in treatment is due to the fact that they are completely different reasons as to why the strokes occur.
What REALLY causes strokes?
Jon Olney saw the neural damage was not uniform - meaning neurons don't die due to loss of oxygen and glucose. He discovered that SPECIFIC cells would die much quicker than others.
These dead ass cells had a lot of Glutamate receptors on them. They would die and release their glutamate content into the extracellular fluid, FLOODING the joint. Then the Glutamate binds to the nearby cells that have Glutamate receptors which allow for greater influx of Sodium, Calcium, and water.
What was the point that we started treating strokes differently?
When Olney found the Glutamate hypothesis
What is Excitotoxicity?
The influx of Glutamate due to the dying cells expelling their contents into the extracellular fluids.
How do we know someone has had a stroke?
F A S T
Speech (not slurring)
Time - get them in hospital QUICKLY
What is it called when the circulatory system is not formed correctly from the get-go?
Where in the circulatory system is transmission of waste product and oxygen/glucose made?
In the Capillaries because they are porous
What does the capillaries seperate?
Veins and arteries
Why are capillaries important?
1. It's where we exchange products with the extracellular fluid
2. Slows down the rate of blood flow - since veins can't expand or contract quickly like arteries, so it's important to have a high functioning capillaries
What's the main difference between arteries and veins?
Veins don't contract and expand like arteries
What is Arteriovenous malformations (AVM)?
Capillaries are either absent or substantially reduced meaning individuals with this can't exchange nutrients and dump waste, so they essentially can't form new neurons.
Also increases hemorrhage due to inability to adjust for blood pressure
What is Cavernous malformations?
What are the symptoms?
Special case of AVM - there is ZERO capillary areas and you have CAVERNS or HOLES in the brain (so no neurons or glias) because the environment in the surrounding area can't help grow.
Symptoms are headaches, hemorrhages, and seizures.
What is the rate of survival for open head injury?
In general, for closed head injuries, what determines the severity of the consequences?
The longer someone is unconscious
What are symptoms of concussion?
Lack of concentration
Problems with attention and memory
damage to what is more wide-spread? open or closed head injury?
close head injury - physics.
what is the site of the blow in a close headed injury called?
what about the opposite side?
the site of injury is called coup, and the bounced area is the counter coup
What is hematoma?
blood vessels around the surface of the brain cause ruptures of structures which trap fluids in the dura and pia (sub hematoma)
What causes white matter damage? why?
close headed injury can cause twisting of the brain within the skull affecting the axon pathways that descend down to the medulla and spinal cord
what do doctors due in response to major swelling from a close headed injury?
sometimes they open that bitch up to relieve it from swelling
What gene can influence CTBI (chronic traumatic brain injury)?
the APOE4 gene - the E4 allele is unable to break down the beta-amyloid (waste product of the cell)
Which gene can make the brain more vulnerable to effects of brain injury?
The APOE4 gene
what is tumors defined as?
independent growths of cells with no function
what's the diff. between malignant and benight tumors?
they're both cancers - malignant tumors metastasize (shed) and usually return after surgical removal, whereas benign tumors have regular borders and don't shed and spread their cells.
if someone has a tumor in the medulla, what's the best treatment?
best to leave it alone because the risk of cutting into the medulla is certainly death.
what are the major problems with brain tumors?
-chemical agents don't cross the BBB unless there's massive doses or directly on the brain
what is the easier tumor to remove?
meningiomas because it's on the surface of the brain
what is the WORST diagnosis?
medulloblastomas - fatal within 2 years
what is the most common type of tumor?
gliomas - 45% of all brain tumors
thalidomide starves tumors by reducing growth of blood vessels - was discovered when pregnant women gave birth to deformed babies (who didn't grow blood vessels)
what brain structure does seizures seem to be involved with?
epilepsies may be related to what type of neurotransmitter?
GABA - not enough GABAergic activity
what does photosensitive epilepsy indicate about which NT is involved?
That perhaps there isn't enough GABA to inhibit or gate the senses like the flashing lights; etc.
what are the 2 types of seizures? what's the difference?
partial seizures -definite point of origin and spreads from initial area
generalized seizures - entire brain is affected
difference between the two is the point of origins
which type of seizure is preceded by an aura?
partial seizures = aura
which seizure causes memory loss and confusion:
a. partial seizures
b. simple partial seizures
c. complex partial seizures
d. grand mal seizure
complex partial seizures produce memory loss and confusion
where does complex partial seizures begin?
in the temporal lobe (makes sense because it affects memory)
what type of symptoms do grand mal seizures produce?
loss of consciousness, urination, defecation, sweat and saliva production due to activation of ANS
what is the main identification of grand mal seizures?
the cycling of tonic and clonic, followed by a coma.
tonic - short intense muscle contraction
clonic - rhythmic contractions
what is petit mal seizure?
loss of consciousness but pxt doesn't fall over... just not aware of the environment.
what's the best treatment of epilepsy?
GABA agonists and sodium channel blockers.
what type of diet is recommended for children with epilepsy?
high protein (ketogenic) - increase fat levels, decrease glucose levels. Blood chem must resemble starving state. Since seizures require intense amounts of glucose to sustain that energy...
what is neurocysticercosis?
infection through pork tapeworm - larvae burrow urrwhurr.
what's the difference between encephalitis and meningitis?
encephalitis = inflammation of brain
meningitis = inflammation of the layers of the brain
describe the difference between primary and secondary encephalitis.
primary - west nile virus; IN the brain itself.
secondary - chickenpox; starts in the body and goes into the brain
what are the treatments for encephalitis?
there are none - prevention is key; vaccines will work.
what are the symptoms of transmissible spongiform encephalopathies (TSE)?
psychological disturbances - paranoia, anxiety; etc.
progressive loss of cognition
*mad cow disease
what are the different types of TSE?
First described in 18th century
-Bovine spongiform encephalopathy (BSE or “mad cow”; cattle)
-Creutzfeldt-Jakob disease (humans)
First described in 1940’s
0.5-1 case per million worldwide
South Fore of New Guinea
Cannibalism of relatives
-New variant Creutzfeldt-Jakob disease (vCJD; humans)
what causes TSE?
-TSE infectious agents differed from viruses:
>long incubation period (>1 year).
>lack of inflammation.
immunity to hospital sterilization techniques.
-All viruses contain DNA or RNA which can be destroyed by sterilization techniques.
-Prusiner isolated abnormal single proteins called “prions.”
>Much like a regular protein found in all cells, just abnormally folded.
>Arises from a single-point mutation.
>Abnormal prions have the ability to change normal prions into abnormal ones
>The abnormal prions reproduce extensively and explode the cell
what are prions?
crazy ass horny cells - everyone's worst nightmare. it's a protein that is just abnormally folded, occurs from a single point mutation, and has the ability to reproduce like mad and explode cells.
Describe the Kennard Principle (recovery from brain damage).
Which hemisphere appears to recover faster?
When do most recovery occur following an injury?
>Recovery from brain damage is a function of developmental stage.
>Appears to be more true for left-hemisphere functions (language) than right hemisphere functions (spatial abilities)
>>This may be due to the fact that left-hemisphere functions mature earlier than right-hemisphere functions.
-Language functions show more recovery than other cognitive processes.
-Most recovery occurs within the first 6 months following injury.
what type of effects does AVM have on hemorrhages?
A lack of capillaries prevents the slowing down of blood flow, and since veins can't contract and expand like arteries can, the flow of blood can cause intense swelling and bursting - thus producing a hemmorhage.