Neurological disorders Flashcards
2nd most frequent cause of death worldwide
Stroke
Strokes are associated with ____ heart disease
Ischemic heart disease
1 in _ adults experience a stroke in their lifetime
4
True or false : chances of stroke increase with age
True (double each decade after 45yo, until 1-2% per age by 75yo)
Main cause of stroke
Atherosclerosis
Atherosclerosis
Process in which linings of arteries develop a layer of plaque
What forms the layer of plaque of Atherosclerosis
Deposits of cholesterol, fats, calcium, and cellular waste products
Risk factors of strokes
Age, high blood pressure, smoking, diabetes, high cholesterol levels, obesity, poor diet, and lack of exercise.
Atherosclerosis is also a precursor to …
Heart attacks (myocardial infarction)
Atherosclerotic plaques often form in the ___ ___ artery
Internal carotid artery
The internal carotid artery supplies blood to the ___ ____
Cerebral hemispheres
Atherosclerotic plaques cause narrowing of the ____
Artery
Narrowing of the artory increases stroke risk by increasing ___ _____
Blood pressure
Narrowing of the artery can be visualized in an ____
Angiogram
An Angiogram is produced by injecting ____ ____ into the blood and examining the artery with an X-ray.
Radiopaque dye
Stroke caused by blockage of a cerebral blood vessel
Ischemic stroke
Treatment for an ischemic stroke
Thinning the blood to dissolve blood clots
Most common stroke type
Ischemic (87% of time)
Name for the clot that forms within a blood vessel reducing blood flow to the affected area
Thrombus
This clot can directly cause a stroke, or pieces that break off may form an embolus that blocks the artery.
Thrombus
What is an embolus
When a piece of tissue (blood clot, fat, or bacterial debris) dislodges from its site of origin and occludes an artery.
An embolus can cause a ___
Stroke
As the thrombus gets bigger, blood pressure _____.
Increases
Eventually, a small piece of thrombus breaks off : we call it an ____
Embolus
Embolus gets into capillaries, and restrict blood flow to specific areas of the ____
Brain
Hemorrhagic stroke
Rupture of a cerebral blood vessel, causing blood to leak out.
What is the goal of hemorrhagic stroke treatment ?
Make the blood thicker and increase blood clots.
Hemorraghic stroke reduces access to ____ for the neurons by compression
Nutrients
Brain damage from stroke varies based on the size of the ___
Affected blood vessels
Once neurons don’t receive nutrients, they die within …
A half hour
What types of therapy may held brain function improve after permanent brain damage ?
Speech, occupational, physical
What method might minimize brain damage from Ischemic stroke ?
Administer drugs that dissolve blood clots to reestablish circulation.
“Clot-busting” drugs are called ____
Thrombolytics
This thrombolytic works best when given a few hours after an Ischemic stroke
tPA (tissue plasminogen activator)
Devices to secure/remove occlusion are often thread through the _____ system to the site of an occlusion.
Vascular
3 devices that may be used to secure and remove occlusions
Coils, aspiration devices, stents
Stents also physically ____ arteries
Enlarge
Drugs for stroke treatment reduce swelling and inflammation in the ____
Brain
Diet and exercice are recommended after a stroke to reduce _____
Cholesterol
What type of stimulation might help after a stroke ?
Sensory stimulation
Constrain-induced movement therapy
Being forced to use your weak side
After a stroke, you get back to childhood level and need to create new neuronal connections to ____ the brain
Rewire
Tumor
Mass of cells whose growth is uncontrolled and that serves no useful function.
What creates uncontrolled cell growth ?
A cell starts dividing uncontrollably because of genetic mutations.
When do genes get genetic mutations ?
Every time a gene divides, it gets a gene mutation.
What makes a cell more likely to divide uncontrollably ?
Some cells over time get the perfect combination of gene mutations to divide too much.
Cells that divide the most are ____ prone to cancer
More
True or false : Neurons in our brain don’t cause cancer because they do not divide.
True
What cells in the brain CAN cause cancer ?
Glial cells
Non-malignant tumor
Noncancerous (“benign”) tumor.
What is the border of non-malignant tumors like ?
Distinct border
Can non-malignant tumor cells metastasize ?
No
True or false : non-malignant tumors are easier to remove
True
Malignant tumor
Cancerous (“harm-producing”) tumor.
Can malignant tumor cells metastasize ?
Yes
What is the border of malignant tumors like ?
Lacks distinct border
Metastasis
Process by which cells break off from a tumor to go grow elsewhere in the body
What pathway do cells from a tumor use to travel through the body ?
The vascular system
Major distinction between malignancy and non-malignacy
Whether the tumor is encapsulated (distinct border between the mass of tumor cells and the surrounding tissue)
When an encapsulated tumor gets cut off, it will not ____
Regrow
if the tumor is cancerous it grows by ______ the surrounding tissue, and there will be no clear-cut border between tumor and normal tissue.
Infiltrating
When surgeons remove malignant tumors, some cancer cells are missed, and they produce ____ ______.
New tumors
Any tumor growing in the brain, malignant or benign, can produce _____ symptoms and threaten the patient’s life
Neurological
Tumors damage brain tissue by two means:
- Compression
- Infiltration
Compression can directly destroy brain tissue, or it can do so indirectly by blocking flow of _____ ____
Cerebrospinal fluid (outflow)
Hydrocephalus/water brain
A brain filled with cerebrospinal fluid due to compression
Where do tumor initiating cells originate from in gliomas ?
The neural stem cells that make glia.
Medulloblastoma
Neural stem cells that give birth to neurons and glia that will form the cerebellum starts to divide uncontrollably (cancerous tumor).
How do glia tumor cells differ from other tumor cells ?
They rapidly proliferate and are more resistant to chemotherapy and radiation than most tumor cells.
The survival rate from malignant gliomas is very ____.
Low
This method can be successful at curing tumors.
Extract blood, put the blood cells in a petri dish and add DNA into them. We then make the immune cells expert at killing the tumor cells.
Meningioma is an example of a non-malignant tumor because…
It is encapsulated in the meninges.
How can meningioma still be dangerous even if not cancerous ?
Danger of killing neurons by compression if not taken out.
What are meningioma tumor cells composed of ?
Cells that constitute the meninges – the dura mater or arachnoid membrane – often right between the two cerebral hemispheres.
Usual symptoms of meningioma
Long-lasting headache and weakness on a side of the body
A big meningioma tumor can cause a ____
Stroke
The immune system is trying to fight viruses off, but if the virus or the inflammation gets severe enough, it can cause _____damage.
Brain
Encephalitis
Inflammation of the brain caused by infection (bacterial or viral), toxic chemicals, or allergic reaction
Symptoms of encephalitis
Headache, fever, nausea
Meningitis
Inflammation of meninges caused by viruses or bacteria
Meningitis symptoms
Headache and stiff neck
Meningitis treatment
Antibiotics
Polio (acute anterior poliomyelitis)
Viral disease that destroys motor neurons of the brain and spinal cord, causing paralysis (in a small fraction of people).
Viral disease that launched the vaccine movement
Polio
Viral disease that causes brain damage and death; usually transmitted through the bite of an infected animal
Rabies
Rabies enters the ___ neurons
Motor
Rabies replicates until ____
Death ☠
What is the treatment for rabies ?
Maximum 2 weeks to treat it with antiviral medication
Herpes simplex virus
Virus that normally causes cold sores near the lips or genitals.
In rare cases, herpes enters the brain’s, causing _____
Encephalitis
Leading cause of death in young people
Traumatic brain injury
Closed-head injury/concussion
Caused by a blow to the head with a blunt object
True or false : a closed-head injury can make you lose consciousness
True
Symptoms of a closed-head injury
Tiredness, nausea, dizziness
Once you have a concussion, it’s better to avoid … in the future
Another concussion in the future
Coup
When the brain comes into violent contact with the inside of the skull
Contrecoup
After the coup, when the brain recoils in the opposite direction and smashes against the skull again
Open-head injury
Caused by penetrating brain injuries (open head injuries), something enters the brain.
In an open-head injury, damaged __ ___ exacerbate the injury
Blood vessels
In open-head injury, there is increased ____in the brain due to blood loss
Increased pressure in the brain due to blood loss
2 causes of brain damage in open-head injury
Pressure and inflammation
What is the role of glial cells in both types of brain injury ?
Glial cells divide to try to fix the problem and cause increased pressure in the brain.
When this fluid builds up, the brain injury is an emergency
Cerebrospinal fluid
How do doctors treat cerebrospinal fluid build-up?
The doctor will drill a hole into the skull
scarring often forms within the brain, around the injury, which increases risk of developing ____
Seizures
How do brain injuries disturb the neural network, increasing seizures risk ?
There is an imbalance of excitatory and inhibitory neurons around the scar tissue, and if a few become hyper excitable, it can cause seizures.
True or false : Even mild, undiagnosed cases of TBI (mTBI) greatly increase a person’s risk of developing neurodegenerative diseases down the road.
True
True or false : TBI increase the risk of getting Alzheimer earlier
True
The most common cause of seizures
Scarring due to injury, stroke, tumor or developmental brain abnormality
2 other causes of seizures
High fevers (especially in young children) and withdrawal from GABA agonists (alcohol and barbiturates)
When people take a lot of the sedative barbiturate or alcohol, the brain gets used to turning down the expression of ____ because of their boosting from substances.
GABA receptor
If people try stopping sedatives after decades of use, it can lead to death because of too much _____ in the brain.
Excitation
Why is it difficult to treat alcohol induced seizures ?
Usually seizures are treated by sedatives, but alcoholics already have inhibition from alcohol, so they end up having too much GABA inhibition.
Gene mutations cause neural network instability by affecting … (3)
- the amount/function of different ion channels in the brain
- the reciprocal wiring of excitatory and inhibitory neurons
- the rules that govern synaptic plasticity
True or false : neurons just have to be too excitable in a small area of the brain to destabilize the entire network
True
Preferred term for epilepsy
Seizure disorder
True or false : most seizures involve convulsions of the body
False
The seizures that cause muscle contractions affect ____ neurons
motor neurons
Convulsion
Violent sequence of uncontrollable muscle movements caused by a seizure.
Partial (focal) seizure
Seizure that begins at a focus and remains localized, not generalizing to rest of brain. It can occur anywhere in the brain.
The symptoms of a partial seizure relate to the ___
Part of the brain undergoing the seizure
Simple partial seizure
Does not procure loss of consciousness
Complex partial seizure
Procures a loss of consciousness
When people have many seizures, the seizures tend to recruit more neural ____ , and grows and spreads around the brain.
Neural tissue
Why do synaptic connections strengthen during seizures ?
All neurons start firing at the same time during seizures, and strengthen synaptic connections, allowing the seizure to spread further and further.
Generalized seizure
Seizure that involves most of the brain (a non-localized seizure).
3 types of generalized seizure
tonic-clonic seizures, atonic seizures, and absence seizures
Generalized seizure always involves …
Loss of consciousness
Seizures can spread across neighboring areas of the brain ____ and _____episode
Within and across
What will the doctor do if you have 1 seizure ?
The doctor will try to identify a specific change to not make it happen again
What is the effect of drugs used to treat repeated seizures ?
GABA agonists to boost GABA activity, or drugs that block specific ion channels
People can have seizures induced in hospitals and then have the ___ starting the seizure removed
neurons
Why does removing brain tissue usually help seizures ?
Dysregulated neurons are destabilizing the brain and reducing functions. Removing them gives the surrounding neurons the chance to get back their original function.
Grand mal seizure is usually in ___ adults/children
Adults 🧑
Aura
Sensation that precedes a seizure. Not painful.
Tonic-clonic seizure (type of grand mal)
A generalized, grand mal seizure that typically starts with an aura, followed by a tonic phase and then a clonic phase.
Tonic-clonic seizure always involve…
Convulsions
Tonic phase
First phase of tonic-clonic seizure, in which all of patient’s skeletal muscles are contracted. The patient loses consciousness.
Clonic phase
Second phase of a tonic-clonic seizure, in which patient shows rhythmic jerking movements. People can hurt themselves at this stage.
What happens after the clonic phase ?
Transition to sleep
True or false : children are especially susceptible to seizure disorder
True
Many children do not have tonic-clonic episodes but instead have brief seizures that are referred to as spells of _____
Absence
Absence seizures are also known as ____
Petit mal seizures
What happens during absence seizures ?
People stop what they are doing, stare off into the distance, and often blink their eyes repeatedly. Most absence seizures are less than 15 seconds and there are no convulsions.
Behavior of neurons in absence seizures
All neurons go in a wave back and forward.
True or false : People grow out of absence seizures most of the time.
True (and no resulting brain damage)
What causes absence seizures ?
Caused by mutations in the voltage gated calcium channels. Blockers for these channels are effective at stopping them.
3 types of generalized seizures
Tonic-clonic (grand-mal), absence (petit-mal), atonic (paralysis instead of convulsions)
True or false : partial seizures can become general seizures
True (as neurons wire up together)
Seizure disorders are treated with anticonvulsant drugs, such as enzodiazepines, many of which work by increasing effectiveness of _____ synapses
Inhibitory
True or false : Most seizure disorders respond well enough to medications that the patient can lead a normal life
True
What happens when drugs don’t reduce seizures ?
The seizure foci remain so irritable that brain surgery is required
Exposure to certain toxins, viruses, and drugs during pregnancy can …
Impair fetal brain development and cause intellectual disability.
Dangerous toxins
Organophosphates (from insecticides) and heavy metals such as lead and mercury.
Famous viruses that alter brain development include …
Rubella virus (German measles) and the Zika virus (Brazil).
____ is one of the most dangerous drugs during pregnancy
Alcohol
Babies born to alcoholic women are typically ____than average and develop more _____.
Smaller and develop more slowly
Fetal alcohol syndrome
Serious condition associated with alcohol consumption during the 3rd and 4th week of pregnancy, which is associated with certain facial anomalies and severe intellectual disabilities
True or false : Babies can be born addicted to drugs, and go through withdrawal following birth. Afterwards, kids are generally fine.
True
“Errors of metabolism”
Genetic abnormalities in which the instructions for a particular protein are in error.
What is typical enzyme error that causes inherited metabolic disorders
Enzyme is not synthesized on account of mutations in both copies of the gene (it must be from both parents)
Phenylketonuria (PKU)
Recessive ereditary disorder caused by the absence of enzyme that converts the amino acid phenylalanine to tyrosine.
Accumulation of phenylalanine causes brain damage unless a special ____ is implemented soon after birth for the remaining years of life.
Diet
Phenylalanine levels are very ____ without the right enzyme
High
Tay-Sachs disease
Heritable, fatal, metabolic storage disorder in which the lack of an enzyme in lysosomes causes accumulation of waste produces and swelling of cells within the brain
With Tay-Sachs disease, you are missing an enzyme that breaks down ____ to recycle them.
Fatty acids
In Tay-Sachs disease, ___ get bigger until they take over all the neurons, causing death within a few years.
Lysosomes
Can you prevent the birth of a child with Tay-Sachs ?
Yes, by testing embryos
What causes down syndrome ?
Down syndrome is the result of having an extra twenty-first chromosome. You have 3 copies of the twenty-first chromosome.When the sperm or eggs were made, one of those cells got an extra 21st chromosome and then the baby inherited it.
Is down syndrome hereditary ?
It is congenital, meaning there from birth, but it is not necessarily hereditary.
Traits of people with down syndrome
Moderate to severe intellectual disability and physical abnormalities
After age 30, the brains of people with Down syndrome begin to degenerate in a manner similar to that of ______disease
Alzheimer’s disease (because a protein on the 21st chromosome causes Alzheimer’s)
Mosaic down syndrome condition
When half of the cells have the extra chromosome, this happens in normal cell division in the developing embryo.
An autoimmune demyelinating disease that usually starts in people’s late twenties.
Multiple sclerosis
MS is a sporadic disease, meaning…
Not obviously caused by an inherited gene mutation or an infectious agent.
At scattered locations within the _____ system, myelin sheaths are attacked by the person’s own immune system
Central nervous
Sclerotic plaques
Attacked myelin sheaths leave behind these hard patches of debris
True or false : Action potentials do not successfully propagate down demyelinated axons
True
Damage in MS occurs in ____matter (axon paths) throughout the brain and spinal cord, resulting in a wide variety of neurological disorders.
White
Symptoms of MS
Tingling sensations and weakness.
Flare ups in MS
Symptoms recede for varying periods of time then come back
MS is more common in northern climate and ____
Women
Usually, remitting-relapsing MS is followed by _____ MS.
Progressive
Progressive MS
Slow, continuous increase in MS symptoms
True or false : There is not yet an effective treatment for multiple sclerosis
True
Interferon β
A protein that modulates immune system activity, and gets it to focus on something else than myelin
Glatiramer acetate
Flood the blood with peptides that mimic myelin (the decoy approach) so the immune system will destroy them
Hypothesis of cause of MS
A childhood disease disrupts the immune system, causing it to attack healthy myelin later in life.
True or false : you only need to grow up for 15 years in a northern climate for your MS disposition to be set
True
