Chapter 10 Flashcards
Brain damage and neuroplasticity
Name the two process of cells death.
Apoptosis and necrosis
Explain the process and role of apoptosis
Process of programmed safe and clean cell death, internal to the cell to eliminate not useful/damage cells. It can be dysregulated by brain damage causing overactivity or reduced activity
1. Cells shrinking or broken down in smaller segment
2. Absorbed by close immune cells with a cellular debris cleaning role
Explain the process of necrosis
Abnormal process of cell death, that is passive, uncontrolled, and unusual. It is
harmful and causing inflammation to its surroundings, can damage the brain.
- External factor causing the swelling of cells
- Causes the cells to burst
- Causing damage to neighboring cells
What are brain tumors?
Abnormal growth of tissue
Name the different types of brain tumors
Meningiomas and infiltrating brain tumors
Meningiomas are about ____% of brain tumors.
20%
Explain what meningiomas are (benign or malignant, symptoms, treatment procedure)
Brain tumors growing encapsulated in the meninges. Most are benign, so they won’t spread or invade surrounding tissue.
Symptoms are headache and migraines because of the pressure on neighbouring brain tissu. Other symptoms are dependent in the location of the tumor.
We remove them surgically because of the symptoms they cause
Explain what infiltrating brain tumors are (benign or malignant, where do they come from, treatment procedure)
Tumors growing through neighbouring tissue and spreading, coming from other cancer that metastasized, small part of the cancer breaks out, going in the bloodstream and brought to the brain or elsewhere in the body. They are malignant.
Most common treatment are neurosurgical removal and chemotherapy. The injection of microbubbles is being tested
What is the problem with neurosurgical removal for infiltrating brain tumors?
They are difficult to remove or destroy, because they come from elsewhere so they often comes back. For lower grades tumor, they take longer to grow back, buying some time of the patient
What is the problem with chemotherapy?
The Blood Brain Barrier - it is difficult to develop drugs that can bypass it, increasing the dosage of the drug so a little gets in the brain, but increasing the side effects.
What is the new process to help bypass the blood brain barrier, and what it its process?
Injection of microbubbles.
- Injection of microbubbles in the bloodstream
- Targeting the tumor with an MRI to focus the treatment
- Aiming a laser at the microbubbles making them expand and vibrate
- Movement of bubbles poke holes in the BBB allowing the medicine to reach the tumor
- Still under investigation and clinical trial
What is another name for strokes?
Cerebrovascular disorders
What is a stroke? (how common, risk factors)
Interruption of blood supply to the brain, causing brain damage.
It is very common - 3rd leading cause of death in Canada
The risk factors are age, high blood pressure, smoking, diet, and stress.
Age it the ____ important risk factor for a stroke, after ___ years old the risks _____
most, 55, doubles
__% of people will die, __% of people will make full recovery after a stroke, others will have after-effects
15% and 10%
What are common after effects of a stroke?
motor, cognitive, emotional, and psychological - depression, anxiety, and persistent fatigue
What is the acronym to help recognize early signs of strokes, and name other common signs?
FAST
F: Face - Drooping of one side
A: Arms - Motor function affection, one side weaker, can’t lift both arms equally
S: Speech - Slurred, not making sense
T: Time - Important to act fast, even when symptoms are temporary we should go to the hospital
Other: Confusion, balance affected, headache, …
Why what strokes symptoms are temporary we should still go to the hospital?
Because of TIA - Transient ischemic attack: Blood clot separating and getting stuck somewhere else
Why are strokes often causing unilateral effects?
Most blood vessel supply one hemisphere only
What are the major focus of research for strokes?
Keeping people alive - Before, strokes were even more deadly, so we needed to find solution to keep people alive.
Motor rehabilitation - 10-15 years ago we started focusing on getting people to walk and speak again
Then, in the last 10 years, it switched from focus on motor rehabilitation to more cognitive and emotional rehabilitation - Memory, attention, processing speech, executive function, language, …
Why did the research focus for strokes turned to cognitive?
Important research showed that people are better at coping/compensating with motor function loss than cognitive or emotional ones. People prefer gaining these function back so they can maybe go back to work
Name the type of strokes.
Cerebral hemorrhage and Cerebral ischemia
What are cerebral hemorrhage and its different types?
Blood vessel rupturing causing bleeding in the brain.
Subarachnoid stroke - Bleeding at surface of the brain in subarachnoid space
Intracerebral stroke - Bleeding deep inside the brain
Hemorrhage strokes are often caused by ___? (What, how common, risk, interventions)
Aneurysms are weakened spots causing balloon like bulges in the walls of blood vessels
They are very common, most of the time we don’t know we have them
The risk will depend on the size, person’s health and age. There is a higher risk of rupturing causing a stroke when mixed with other risk factors, especially high blood pressure
Interventions are made to isolate the aneurysms from the blood circulation
Clipping of aneurysm: using a clip to isolate it
Coiling: Filling it with coil
What are cerebral ischemia and its different types?
Interruption in the blood supply to the brain caused by a blockage/blood clot.
Thrombotic: Blood clot formed in a blood vessel supplying directly to the brain, not moving from its point of origin
Embolic: Blood clots formed elsewhere that get detached and get stuck in a blood vessel feeding the brain.
What are ischemic strokes often caused by?
Atherosclerosis, the narrowing of arteries. When getting older, there build up of substances in arteries (fat, calcium…) making the artery less flexible and making it more likely for clot to get stuck
Ischemic strokes are ___ dangerous than hemorrhage strokes, and are __% of strokes are ischemic
Less and 85%
Which ischemic stroke is the most dangerous and why, thrombotic or embolic?
Embolic are more dangerous because of the apparition of symptoms.
In embolic strokes symptoms appear suddenly when the clot gets stuck in the vessel supplying the brain, our body doesn’t see it coming.
In thrombotic the clot gradually forming will make symptoms appear gradually, giving more time to realize before the stroke
Describe the process of cell damage due to cerebral ischemia
Interruption in blood supply means certain cells are not receiving the oxygen they need making them overactive.
- Ion pumps of cells not receiving oxygen they need will stop working
- The stopping of sodium-potassium pump causes buildup of sodium ions in the cell causing cell to depolarize
- Sodium is also salt, making the cells thirsty, so they will take in more extracellular fluid
- Making the cell swell and burst - Calcium pump not functioning will cause a buildup of calcium ions in the cell causing NT to be released (mostly glutamate)
- Tone of glutamate is released in the synapse binding to postsynaptic neurons and contributing to it’s depolarization
- Damage will spread slowly from cell to cell and overactivity in the brain will increase, because the postsynaptic cell receiving all the glutamate are overstimulated, causing them to start producing excess glutamate
What treatment can be used for ischemic strokes, its effect and administration time.
Extremely powerful blood thinner administration - tPA
Stops the sequence of event happening in the brain, but cannot restore any brain damage. Needs the be administered in the first 3h of first stroke signs
Why tPA needs to be administered before a certain point in ischemic strokes?
If administered after 4h because blood vessel walls are weakening, sudden return of blood flow could lead to rupture creating hemorrhage.
What different closed head injuries did we saw in class?
Cerebral contusions, concussions, punch drunk syndrome/chronic traumatic encephalitis
What is a cerebral contusion?
The brain collides with the skull causing bruising to the brain. Swelling and bleeding can also happen
What type of injury will often happen with a contusion and what is it?
A coup-contre-coup injury is an impact after impact. After the first impact, the brain bounces back and hitting the opposite side
Is a cerebral contusion a functional or structural injury?
Structural, can be visualized with structural imaiging
What is a concussion?
Brain moving inside the skull because of a too fast acceleration/deceleration of movement causing disturbance in the brain’s function
Are concussion structural or functional injuries?
Functional, because it affects/disturbs the brain function.
What other name is given to a concussion, and what is the problem with it?
A mild brain injury, but it is misleading because it is suggesting that concussions does not have a big impact on people’s lives, but can have a big impact and they need to be taken seriously.
What are common symptoms of concussions?
Loss/altered level of consciousness, memory loss, confusion, headache, sensitivity to light and sound, nausea and vomiting, and loss of balance.
Why can we experience sensitivity to different senses after a concussion?
Because of issues caused to the thalamus. The thalamus is the sensory relay, so it is harder for our brain to deal with sensory input.
What is the recovery process and why is it important to follow it?
The recommendations are to reduce activity level to a minimum. When we have no more symptoms, activity can be progressively started. If symptoms reappear, we needs to start over.
If the recommendations are not followed, it can lead to a post-concussive syndrome.
What is the other name for punch drunk syndrome and in who was it first recognize?
Chronic traumatic encephalopathy (CTE), recognize first in boxers.
What is the punch drunk syndrome and how do we diagnose it?
Permanent damage after multiple concussion and repeated blow to the head.
It is only diagnosed at autopsy.
What are the symptoms or CTE
Memory impairments, executive functions, mood disturbance, dysregulated behaviours
CTE of otfen mistaken for what disease and why and what are the differences in symptoms?
It is often mistaken with Alzheimer’s disease because they have similar markers, but the early development of Alzheimer are memory impairments and CTE’s early symptoms are behavioural and emotional changes.
What are examples of dysregulated behaviours in CTE?
Increase aggression, substance abuse, depression, irritability, …
Often, the cause of death observe in patient with CTE was…
Suicide
What are brain infections and what is it typically leading to?
Any invasion of the brain by microorganisms typically leading to encephalitis or meningitis.
What are meningitis and encephalitis?
Meningitis is the inflammation of the meninges and encephalitis is the inflamation of the brain.
What are the differences between viral and bacterial meningitis?
Bacterial is extremely dangerous, fast moving and treated with antibiotics. Viral is much more common and less dangerous. Most healthy people recover without any treatment.
Some _____ infections have preferred places to attack, the most common place to attack is the ___, e.g., _____. Some can attack anywhere and don’t show preferences, e.g., _____ and _______.
Viral, CNS, Rabies, herpes, and mumps.
What are neurotoxins and where do we often find them?
They are toxins that affects the neurons, most common in occupational settings like work and industrial processes.
Repeated exposure to neurotoxines can lead to…
CTE
Give an example of a well known neurotoxin, and what type of product it is.
Organic solvents are lipophilic products.
What is a lipophilic product?
Products capable of combining or dissolving in non water-soluble materials like fat
What are point of entry for neurotoxins, and what is the most common?
Injection, absorption, and the most common inhalation.
_____ products spread easily in the CNS because all the ____ _____ ____ cell membranes are made of ____. Cells will absorb these products and it will spread in the brain.
Lipophilic, blood brain barrier, fat.
Name the progressive neurological diseases we saw in class
Alzheimer, epilepsy, parkinson, huntington, and multiple sclerosis
__% of the __y/o population has Alzeimer’s disease. Looking at the population, cases of alzheimer _____ every __ years starting at __ y/o groupe age
35%, 85 y/o, doubles, 5 years, 65 y/0
What are the symptoms of Alzheimer
Early stage is characterized by Decline in memory and other cognitives abilities affected early in the disease are language, visuospatial perception, and executive functions
When and how can Alzheimer be diagnosed
Diagnosed officially at autopsy if two pathological findings are observed
Neurofibrillary tangles and Amyloid plaques
Tangles are found inside the neuron and are made of abnormally modified tau protein. Normally, tau protein dinds to the microtubules to help with their stability but in the disease, it moves away from the microtubules, clumping inside the cell making it die
Plaques are found in the extracellular space, between neurons, and are clumps of protein
Why does Alzheimer’s disease create memory and language impairments?
Plaques and tangles spread in the brain in a very predictable fashion.
1. Accumulating in the hippocampus region
2. Spreading to language areas: Broca’s area and Wernicke’s area 2-10 years after the onset symptoms
3. In the later stages plaques and tangles are in the entire cortex and the hippocampus is gone. Plaques and tangles have created holes and larger ventricles due to atrophy of the tissue.
Treatment for Alzheimer
No current treatment, but new ones in testing, because treatments would need to be used early in the disease progression, but possible Alzheimer is often diagnosed late.
The solution would be finding tools to detect it earlier
Plaques and tangles can start developing up to ____ ____ before the apparition of symptoms
20 years
What is epilepsy?
Multiple repeated and unprovoked seizures, uncontrolled electrical disturbance in the brain
How do we diagnose epilepsy
An EEG is used to look at abnormalities in brain activity, but it is complex to do, because of the complexity and diversity of seizures.
Name the types of seizures
Focal/partial, generalized seizures
What are focal seizures and the types? (Symptoms, consciousness, duration)
Originate in a specific part of the brain and spread outwards. Point of origin of the seizure is called the focus.
Simple/Jacksonian seizures: Movement or sensation corresponding with the focus.
Not accompanied with loss of consciousness, the person can remember what happened during the seizure
Typically a minute or less
Complex: Normally starts in the temporal lobe, creating automatisms like smacking, chewing, swallowing, finger robbing
Associated with a change in consciousness, during the seizure the person is likely to be confused and after, having no memory of the seizure
About 1-3 minutes, but the person might not return for normal functions for hours after
What are generalized seizures and the types (sequence of events)
Don’t have a focus or have a focus but still affects the whole brain and both hemisphere.
Tonic-clonic:
Tonic phase - loss of consciousness and muscle contractions.
Clonic phase - Intense tremors and violent muscle contractions that can result in physical injuries.
Cycle is often followed by a period of coma that can last a few minutes.
Absence:
Loss of consciousness, person won’t be aware of their surroundings for about 10 seconds during which motor movements will be limited: eye movements, blinking, head turns, …
What is the problem with absence seizures and why?
Often misdiagnosed. Is very difficult to observe without an EEG, often a person with absence seizures will be described as distracted or daydreaming. Can mislead during neuropsych evaluations.
What are the movement disorders we discuss in class and what is the problem with that way of naming these?
Parkinson, Huntington, and Multiple Sclerosis
The problem with that name is that it is eclipsing the cognitive and emotional deficits caused by these diseases, because the motor symptoms are more noticeable, researches were focused on motor problems
Parkinson’s disease (age of onset, common, diagnosis)
Age of onset is 60 y/o
About 100,000 Canadiens have this disease
The diagnosis is done based on the motor symptoms - The most used is unilateral resting tremors
What are the primary and secondary motor deficit caused by Parkinson?
Primary motor symptoms are resting tremor, trouble initiating movement, bradykinesia, muscular rigidity
Secondary motor symptoms are micrographia, disartria, flat facial expression, gait impairment
What are resting tremors?
A unilateral tremor typically reduced/stopped when the muscles are not relaxed.
What is bradykinesia?
Slowness of movement
What is micrographia?
Abnormal handwritting - small and cramped
What is disartria?
Poor articulation
What is gait impairment?
Walking and movement pattern issues
What are common cognitive deficits in Parkinson?
Attention, Working memory, Executive function, and Speed of processing
In Parkinson, part of motor issues can be caused by ____ _____
Mental slowness / Speed of processing
Parkinson’s disease is caused by?
Degeneration of neurons in the substantia nigra of the basal ganglia which normally produces dopamine, but in the disease the cells gradually dies and dopamine production is greatly reduced, causing problems initiating movement
Dopamine is important for…
Important for regulating movement, cognitive and emotional functioning
What are treatments for Parkinson
Injection of L-dopa, only effective temporarily becomes less effective with continued used and their are many side effects that can produce involuntary movement
Deep brain stimulation of the subthalamic nucleus - sending electrical impulses via electrodes
What is L-dopa, why do we use it, and when do we stop using to treat Parkinson
L-dopa are chemicals converted in dopamine by the body
Dopamine cannot bypass the BBB but L-dopa can diffuse in brain cell membranes
We stop when the side effects outweigh the disease
In Parkinson, the deep brain stimulation helps mainly with ___ _____
Resting tremors
Why is deep brain stimulation not a first line response to Parkinson’s disease and when do we use it?
Effects are not always optimal, it is an invasive and major surgery. It can cause many side effects.
Emotional problems like anxiety and depression, tingling and numbness sensation, speech problems in verbal fluency, balance problems, mood changes
A psychiatric evaluation is required before the surgery
Used only when L-dopa stopped functioning
What is the cause of Huntington’s disease?
Genetic disorder caused by a mutated huntingtin gene, a condition called an autosomal dominant condition. The mutation will damage the brain, particularly the basal ganglia causing the body to overproduce dopamine
We all have 2 copies of every gene, one from mom and one from dad, so each parent have 50% chance of transmitting one gene or the other to the child. If the child inherit the mutated gene from one parent, they will develop the disease.
What is an autosomal dominant condition?
A condition in which the mutated gene is dominant to the non-mutated one. If you have the mutated gene, it will always develop into the disease.
Dopamine overproduction causes?
To much movement and difficulty to stop them.
How do we diagnose Huntington
Based on the motor symptoms
What are the symptoms are Huntington
Chorea and later in the disease severe dementia
What is chorea and it’s evolution in Huntington
It is a movement disorder leading to choreic movements, movement that are dense, involuntary, excessive, irregular, random, and non-repetitive involving various part of the body.
They increase in intensity and severity with the disease progression
What are the effects of Huntington observable on the brain?
Accumulation of mutated protein at different degree in different place in the brain causing enlarged ventricles due to atrophy of surrounding regions like basal ganglia
Treatment for Huntington
There is not treatment to cure this disease, but there is one approved medication in north america to help with the symptoms -
Tetrabenazine, a medication to lower temporarily dopamine levels
What is sclerosis and multiple sclerosis?
Sclerosis is the abnormal formation of scar tissue
MS is an autoimmune condition, attacking the CNS and particularly oligodendrocytes, creating damaged leading to sclerosis plaques replacing the damaged myelin, this will form in multiple regions of the brain disrupt the normal transmission of electrical signals.
What is an autoimmune condition?
The immune system will attack the body’s healthy tissues.
What is the role of oligodendrocytes?
Glial cells forming the myelin around axons
What is normally the first symptom of MS and what are the other symptoms of MS, and the severity varies based on what?
Nature and deficit severity varies with the nature, size, and position of sclerosis lesions in the brain
Optic neuritis if often the first symptoms
Other symptoms are muscles weakness, numbness, tremors, and ataxia
What is optic neuritis and what is it seen in people with MS?
Visual disturbances - blurred or doubled vision.
Due to inflammation and loss of myelin covering the optic nerves.
What is ataxia?
Loss of motor coordination.
Name the type of MS we discussed in class and what it is.
Relapsing-remitting MS is characterized by different periods, relapses and remissions. This type is more progressive than other types, so the symptoms will get progressively worse over time and the remission period will stop eventually.
Relapses: Are flare-ups/attacks
Remission: Symptom free period
What are the causes of MS?
It have some genetic factors, but it is mostly due to environmental factors, like exposure to various viruses or lack or vitamine D.
What virus doubles or even triple the risks of developing MS and why?
Mononucleosis, because it alters our immune system.
Because of the lack of exposure to the ___, risk of MS in ______ are among the highest in the word, and ____ ______ the highest in the country.
Sun, Canada, Nova Scotia
Treatment for MS
No cure has been found, some medications are used to reduce attack severity and/or slow the progression of the disease
Responding to NS damage, what are the types of neuroplasticity made in the brain?
Reactive neuroplasticity and experience dependent neuroplasticity
What is reactive neuroplasticity and when does it happen?
Spontaneous development of new neurons, growth of axons and dendrites, creation of synapse, and strengthening of synapses happening after nervous system damage, normally within days or weeks after the damage.
What is our understanding of reactive neuroplasticity?
It explains the drastic improvement someone can have by doing nothing right after an injury. We don’t understand it well yet and were not sure if it is enhance by anything, but we know that it happens regardless of what people do
What is experience dependent neuroplasticity and when does it happen?
It is the learning and relearning things after a nervous system damage that will cause the growth and strengthening of synapses and the creation of new neurons
It is more inhance in the time following an injury, but it never fully stops.
The impact of experience dependent neuroplasticity depends and what and why? How can we enhance neuroplasticity
Depends on the range of learning opportunities available! Using many varied and new ways to relearn is super important to enhance this neuroplasticity, the key is novelty. Novelty is the key because if it’s new, the brain need to keep integrating and create new pathways, if it’s not, the pathways are already created
Neuroplasticity can be enhanced with anything new, challenging, and stimulating. It needs to be something the patient is interested in so they are stimulated. But novelty is really the key!
Give examples of things we can do to enhance neuroplasticity.
Physical activity and body movements, learning new skills, challenging your cognitive abilities, adequate sleep, stress management, and social interactions
Why is adequate sleep and stress management important to enhance neuroplasticity?
Sleep to consolidate the new learnings.
And stress management to avoid high level of cortisol, because it inhibit neuroplasticity and reduce its impact
Name the neurological condition that can be developed after a stroke, and say which hemisphere the stroke must have affected to develop this.
Spatial neglect caused by a stroke affecting mainly the right hemisphere.
What is spacial neglect and when does it happen?
The person will be biased to the right, they don’t pay attention equally to what’s happening on the right or left, paying only attention to the right.
What are the consequences on spatial neglect on life?
People with this condition will often get in accidents, putting themselves in danger by not paying attention to the left.
How is spatial neglect diagnosed, give two example?
With drawing tasks
E.g., circle the stars on the paper - Observing is they neglected the stars on the left.
E.g., Draw the object presented in front of you - Observing is they neglected the left side of the objects/objects on the left
What is the least effective treatment used for spatial neglect and what is the main problem?
Getting patient to relearn to pay attention on both sides emphasizing the left side.
The patient will never learn to automatically look to their left, but will always have to consciously do it.
What experimental treatment is developed for spacial neglect and what is it?
Prism adaptation is a technique inducing neuroplasticity chances by recentering their attention at a subconscious level.
What is the treatment process and learning process of prism adaptation?
Treatment process - Patient are asked to interact with their environment for about 10 session of 10 minute each, wearing prism goggles that shift the vision to the right for approximately 10-15 degrees.
Learning process - When they are first asked to point, they will point so far off that they will automatically correct themselves more to the left and doing so, shifting unconsciously their attention to their left
Why are the effect of prism adaptation long lasting even without the goggles, and what would happen to a healthy person doing that process?
The brain will re enforce these new pathways because the person will be able to interact more appropriately with their environment.
Their spacial attention will go back to normal after a few minutes because they won’t interact correctly with the word and the brain will readapt.
What is the problem and solution to prism adaptation?
The equipment required are only available in rehabilitation center, are expensive, and not standardized.
The solution is being developed by Anne-Sophie Champod in a clinical research focusing on developing an accessible and cheap intervention called Peg-the-Mole
What is the process of Peg-the-Mole?
The patient will be wearing the goggles and a mole will pop out on the screen. They have to touch them before it disappears
