Midterm 1 PSYC 301 Flashcards
Motor function
Key features to examine
Gross appearance of muscle Muscle tone, strength touch for muscle tone quality Look for asymmetries of both sides of body Strength: apply force with muscle
Upper motor lesions
motor neuron coming out of cortex going onto brainstem, or motor neuron coming out from brain stem, down the spinal cord
Damage: reflexes will be overexaggerated - hyperreflexia
Can also cause muscle spasm- spasticity
lower motor lesions
neuron exiting spinal cord to control the muscle and attach to the muscle and send ACh signal to muscles
Damage: diminished reflexes - hyporeflexia
Can cause hypotonia - muscle atrophy
Somatosensory Function
“Can you take these sensations and organise them into perceptions?”
Cranial damage - often lead to exaggerated Pain responses
Light touch (“Can you feel this”)
proprioception (“do you have a perception of where your body is in space”)
Testing for astereognosis
Testing for agraphesthsia
How to test proprioception
(“do you have a perception of where your body is in space”)
If the doctor moves your hand with your eyes closed, do you know where they moved your hand to
Due to stretch receptors on muscles
How to test astereognosis
problem with perceiving objects with touch alone (e.g. key- touch and jingle)
They can feel it but cannot perceive what it is
Damage to motor cortex can cause this
Testing for agraphesthsia
doctor writes something on your hand, and reporting what was written
Coordination
Quick, alternating movements Point-to-point movement Heel-to-shin test standing/sitting Gait Romberg test Vestibular info test Poor balance can be nauseating
Coordination Impairments in tests are likely due to
cerebellar lesion/damage or problems with proprioception
standing/sitting
Coordination
Quick, alternating movements
Can occur with multiple sclerosis, or cerebellar tumors, PD, other movement disorder
Make someone move rapidly over and over
Coordination
Point-to-point movement
Ask the patient to touch their nose with their index finger and then touch doctor’s finger with the finger and alternate movement rapidly
Coordination
Heel-to-shin test
Put one heel on the other leg’s shin and move heel up to knee laying on side
Coordination
Gait
manner in which you stand and walk
Unusual gait is often due to cerebellar damage
Coordination
Romberg test
taps into balance problems
Ask the patient to stand with arms out and eyes closed to see if their fall over
Visual info and vestibular input (inner ear info) and cerebellum are all important for balance
This test is testing whether vestibular input and cerebellum are working properly
If they fall, there is a potential problem in the region(s)
Coordination
Vestibular info test
march in place and if there is a rotation, there may be a problem in info from one ear
Mental status Exam (MSE)
Important for people with brain trauma, dementia, other cognitive disorders, etc.
Attention and orientation -> most important as it is needed for every other task
Language
Memory
Visuospatial function
Executive functions
MSE: Attentional + orientation
Observe the patient’s alertness
Spelling a word backwards
Counting backwards from 20
Auditory vigilance - listen to a question
Current whereabouts, time - basic (when, where, what questions) ability to pay attention to the world
MSE: Attentional + orientation
Regions involved:
Focal cortical or subcortical regions
Origin may be diffuse (e.g., toxin)
MSE: Attentional Problems
Contralateral (hemi/left) Neglect
Anosognosia
Contralateral (hemi/left) Neglect
failure to attend to left side of world
No problem with vision
No conscious access to left side of the world
Only eat the left side of plate
Anosognosia
failure of an individual to self-reflect that they have a disorder
Inability to recognize they have a disorder
Regions where damage leads to attentional problems:
Right hemisphere’s attention network
Commonly right parietal lobe
MSE: Language
Individuals with stroke commonly have a problem with language
Fluency
Naming
Repetition
Prosody - the stresses in sentences are important for meaning
Comprehension - listening
Reading
Writing
Praxis - language or attentional or motor areas - ability to follow someone’s request
Apraxia
inability to perform movements when asked often due to damage to parietal lobe
MSE: Language Problems
Aphasia = Problems with language production and/or comprehension Alexia = Problems with reading Agraphia = Problems with writing
MSE: Language Problems
Regions involved
Focal or diffuse damage to the left hemisphere language network depending on handedness
MSE: Memory
Working or short term memory:
Digit span - live a list of number and person must list numbers back
Ideally 7+/-2 numbers
Pointing span - point to different corners in the room in the same order doctor as given
Verbal, visual object learning
Past public/personal events - e.g. who’s the president right now?
Factual knowledge
Important in neurodegenerative disorder, dementia
MSE: Memory
Regions involved
Medial temporal structures (e.g., hippocampus), thalamus, basal forebrain, prefrontal cortex (less common)
MSE: Visuospatial Function tests
Line cancellation - given a piece of paper with lines, and asked to draw lines to create X’s with lines
Contralateral neglect - only cross right side of the page
Copy of geometric designs
Judgment of line orientation
Object/face/color recognition
MSE: Visuospatial Problems
Prosopagnosia = Failure to recognize faces even though they can see the separate features
Agnosia - name for a number of visual perception disorders
Regions involved:
Ventral side of temporal lobe (e.g. fusiform gyrus)
Constructional Apraxia = Difficulty putting pieces of an object together
Dressing Apraxia = Difficulty getting dressed especially when requested
MSE: Visuospatial Problems
Regions involved
Right hemisphere’s attention network
Apraxias tend to be problems with the parietal lobe especially with right hemisphere although not always
MSE: Executive Function
collection of all the most important things that we need in order to be successful in human society (e.g. balancing a number of responsibilities, incorporating new info into our model of the world, making decisions with appreciative social behaviors, being able to deal with immediate and long term goals at the same time, self control, etc.)
Judgment
Verbal fluency
Tests of perseverative behavior (inflexibility of behavior):
MSE: Executive Function
Judgment
Test: clear real life scenarios - what to do with dropped mail -> put in mailbox
MSE: Executive Function
Verbal fluency
E.g. List as many words as you can starting with the letter F
MSE: Executive Function
Tests of perseverative behavior (inflexibility of behavior):
Luria 3-step (fist-edge-palm)
place fist on table and palm down and alternate fist-edge–palm behaviour repeatedly
MSE: Executive Function
Tests of perseverative behavior (inflexibility of behavior):
Drawing loops, alternating patterns
E.g. copying figures with multiple loops - patients with perseveration problems may draw extra loops
MSE: Executive Function
Tests of perseverative behavior (inflexibility of behavior):
Oral trail making test (part B)
Recite the alphabet and numbers from 1 to 26 and recite them in alternating order
“A1B2C3D4….”
MSE: Executive Function
Regions involved:
Prefrontal cortex and/or associated projections mainly to do with executive function
Encapsulated tumours
Tumours (aka neoplasms- new growth) - cells that grow and multiply
Encapsulated: membrane around tumour
meningioma (20%)
Encapsulated tumours
Grow between the meninges
If you remove it - low likelihood that it will grow back
And high likelihood that all of the tumour will be removed
Benign: if removed, little likelihood that it will grow back
Infiltrating tumours
(majority of tumours)
Grow diffusely through surrounding brain tissue
Does not have membrane
Removing the tumour - must remove some tissue and some tumour will be left behind
If failed to remove or destroy them completely, they will grow back
Malignant: invading, recurring, and difficult to remove/destroy completely
Metastatic tumours
(type of infiltrating tumour)
Some infiltrating brain tumours grow from tumour fragments carried to the brain from another body part via the bloodstream
Commonly originate from a breast cancer or a lung cancer
Glioblastoma
most common type of malignant (infiltrating) brain tumour in adults (aka: glioma)
Most malignant
Short survival rate: Median survival rate is around 14-15 months
Strokes
Strokes are sudden-onset cerebrovascular disorders (problem with blood flow in head) that cause brain damage
2nd or 3rd leading cause of death
Most common cause of adult disability
No redundancy in blood flow to the brain
In 3-4 mins of restricted blood flow, the area that is directly affected by the stroke is lost/dead tissue (infarct)
Infarct:
area of dead/dying tissue
Irreversible damage from stroke
Penumbra:
dysfunctional area surrounding the infarct from stroke
tissue in penumbra may either recover or die
Even after the cerebrovascular event has finished weeks later it may die
This area would have had a little but not a lot of oxygen
Doctors try to save this area since infarct is already dead
Type of stroke
Ischemic
Hemorrhagic
Ischemic stroke
resulting from cerebral ischemia
More common (80%)
Problem with blood flow to the area
The further up the artery (thicker), the larger the infarct will be
Hemorrhagic stroke
resulting from cerebral hemorrhage
Blood leaking in brain
Severe - blood is toxic (bacteria + viruses)
Pressure from the blood - spraying fire hose at jello
Cerebral Hemorrhage: aneurysm
- development and age group
Can be congenital or develop later
Common as people get older
People who are up to age 40, have a very low prevalence of aneurysm
At 40-60, about 3.5% of people that are scanned may have an aneurysm
60 and onward, over 5% of people that are scanned may have an aneurysm
Aneurysms are extensions of the arterial wall
Placing pressure in arterial wall -> ballooning effect (bubble
At a certain point, the balloon may rupture, leading to hemorrhagic stroke
Cerebral Hemorrhage: aneurysm
artery or vein?
Usually artery (not veins) - Commonly at base of brain (e.g. Circle of Willis) Circle of willis: Internal carotid and Vertebral artery are connected into a circle
Risk factors of cerebral Hemorrhage
diabetes, hypertension, smoking cigarettes, alcoholism, aging
Cerebral Hemorrhage: aneurysm
Two common treatments
to stop the balloon from growing and rupturing
- Clipping Requires craniotomy (opening up skull)
- Endovascular coiling
Cerebral Hemorrhage: aneurysm
clipping treatment
Requires craniotomy (opening up skull)
slightly lower rate of recurrence than option 2
Older type
High tension titanium clip at the neck of balloon so that the balloon has no blood flow and will not expand
More successful in the long run
Risky procedure
Go through skull and move brain bits out of way and clip
Exposing brain to air and infection
Patients must be under anaesthesia for a while which can be dangerous especially for older people
Cerebral Hemorrhage: aneurysm
Endovascular coiling treatment
Much less invasive (less likelihood of infection by exposing brain to air)
slightly higher rate of recurrence than option 1
Create an opening/ put a catheter (tube) in their femoral artery (leg)
The catheter tube runs all the way up to the heart, through the aorta, to the brain
Monitor process with a real time x-ray to watch it go up
The end of the catheter has metal in it (platinum coil) -> push out platinum coils into the inside of the artery
Fill the artery with platinum coils
The metal platinum induces clotting and causes blood to harden, turning the aneurysm into a hard thing without blood flow
Can be dangerous because it forms clots in artery but mostly successful
Sometimes does not stop the aneurysm from growing
Can do on individuals with higher risk
Cerebral ischemia Strokes
A disruption of blood supply to some area of the brain
Blockage of an artery, preventing the blood flow, any of the areas that are downstream are not getting the blood
The neurons of those brain areas quickly start dying
Three main causes of Cerebral Ischemia strokes
- Thrombosis: a plug (thrombus- blood clot)
- Embolism: a moving thrombosis (piece of fat, oil, air bubble, tumour cell fragment in blood stream)
When the arteries are wide, there won’t be a problem but at some point the arteries narrow and will be blocked - Arteriosclerosis
The walls of the blood vessels are thickening and the channels are narrowing
Deposits or build up inside the arterial wall
The thickening of the walls increases the likelihood of a thrombus blocking the artery
Strokes Ischemia-produced brain damage has three important properties:
- It takes a while to develop (can be days)
Much of the damage from ischemia take 1-3 days to develop fully
Should prevent when not fully blocked artery
Better chance of saving more tissue earlier - Damage is more likely in some parts of the brain (e.g. hippocampus - sensitive to damage)
When it is not a full blockage yet (there is still some O2), some areas are more susceptible than others - The mechanisms of ischemia-induced damage vary between brain structures (one example: excitotoxicity and apoptosis)
- The penumbra may or may not die -> reason: can be due to other mechanisms not simply lack of O2
The mechanisms of ischemia-induced damage vary between brain structures
Excitotoxicity
toxic effect caused by too much excitation in the brain
Happens with severe head trauma, apoptosis, epilepsy
The mechanisms of ischemia-induced damage vary between brain structures
Apoptosis
programmed cell death
Glutamate receptors NMDA receptor, which lets in calcium
NMDAR are important for memory formation (strengthen the synapse)
If these NMDAR are too excited, it will let in too much calcium -> high level of calcium will act as a different signal to self destruct
Under normal healthy conditions, apoptosis plays a good role
During a stroke, apoptosis may be triggered and healthy cells will die
During a stroke, How does apoptosis trigger healthy cells will die?
When not getting or limiting oxygen and glucose from blood flow, one of the first things to fail is the Na+/K+ pump (not functioning properly)
Since Na+/K+ pumps are important for maintaining resting membrane potential -> cell starts to depolarize -> triggering action potentials and NT release in some areas
Drugs to block activity of NMDAR (NMDAR antagonist) -> to block calcium from getting into cell -> apoptosis will not occur
NOT SUCCESSFUL - calcium has other ways of getting into the cell (calcium channels) and related to depolarization
Alcohol and ketamine are also NMDAR antagonist
Open-head injuries
aka Penetrating (enters skull) or perforating head injuries (something passes through one side to the other)
¾ of people shot in head die immediately, and 20% more die at hospital
Typically very severe (~90% chance of lethal)
High risk of infection, complications
Open-head injuries examples
- phineas gage
- Ron Hunter
E.g. Phineas Gage - almost died, went through times of infection and coma for awhile
Had confusion and other problems
High velocity worse than low
E.g. Ron hunter -> landed on drill (1.5 in diameter) face first, penetrating and perforating him
Conscious as flown by helicopter to hospital
Moved drill bit through his head
Did not damage any of his brain only pushed it away thanks to his meninges
Ended up bankrupting himself from medical costs
Closed-head injuries (skull not broken): contusion
contusion essentially just means “bruise”
Closed-head injuries that involve damage to the cerebral circulatory system, producing internal hemorrhaging and a resultant hematoma (solid swelling of clotted blood)
Occurs where the brain slams against the skull with huge impact
Considered traumatic brian injury
Contusions (and closed-head injuries in general) are frequently coup contrecoup injuries
Contusions will be visible with imaging
Many types of hematomas, e.g.:
Epidural
Subdural
Intracranial- most severe (in the brain)
Coup vs. countercoup vs. coup counteroup
Place where head hit = coup
If hit hard enough, the brain will bounce off the coup and slam into the the other side (countercoup)
If something hits you standing still-> coup injury
If you run into something stationary -> coup contrecoup injury
Concussion
a syndrome - a collection of symptoms that may arise from mTBI
Problems with sleep, concentrating, mood, irritability, fatigue
Mild traumatic brain injury (mTBI)
When there is a blow to the head but no evidence of contusion or other structural damage with imaging
Typically synonymous with concussion, which is a syndrome (concussive mTBI)
but you can injure your brain without getting a concussion (subconcussive mTBIs)
Couple of concussions are okay - generally
Chronic traumatic encephalopathy (CTE)
aka Dementia pugilistica, punch-drunk syndrome
A progressive, irreversible neurodegenerative disease
Caused by repeated blows to the head
⅓ or more of amateur athletes show evidence of CTE
Not just professional athletes
There is no cure and essentially causes dementia - declining mental abilities, memory problems
Preventible form of neurodegenerative disorders - avoid getting head hit
Not just concussion
They saw evidence in teenagers with signs of CTE -> repeated hits to head
CTE
- parkinsonism
- changes to cognition
parkinsonism (looking like someone with Parkinson’s disease: problems initiating voluntary behaviours, slow to get up, sit down)
changes to cognition: not withholding inappropriate comments, explosive behaviour, volatility, extreme pathological jealousy or paranoia, suicidality, mood problems
2017: former NFL players ___/111 have signs of CTE
who else often shows CTE
110; Any high contact sports
Shows in people with epilepsy, autism (head-bangers), people with domestic abuse
Does CTE correlate with concussions?
Does not correlate with concussions
A number of people diagnosed post-mortem with CTE who never reported having concussions or few concussions
It is the repeated blows to the head
Are there markers of CTE?
Can only diagnose suspected CTE while alive
Must look at the stain of post-mortem brain to diagnose
CTE: Tau & neurofibrillary tangles
Tau (protein) binds and stabilizes the cytoskeleton
When tau comes off the cytoskeleton, the cytoskeleton comes apart
Normal as cell and cytoskeleton must change shape at times
When tau is hyperphosphorylated and stop binding to the cytoskeleton, it aggregates and the cytoskeleton becomes unstable and breaks apart
The tau starts binding to each other and clumps to make neurofibrillary tangles
Not necessarily cause of CTE only correlation
It could be that as neurons die, the tau come off the cytoskeleton and aggregate, and the tangles increases
Also seen in AD, PD - so increase in neurofibrillary tangles does not mean someone has CTE
The fibrillary tangles is a good marker of CTE, but relies on postmortem staining
Tau is probably a marker that cells are dying
Removing tau is not going to get rid of CTE
CTE: Tau & neurofibrillary tangles
Tau progression:
The tangles form in the sulci first and then spread out
Early indicators of mild CTE are in the sulci
Some say that CTE is from mini hemorrhages which cause iron deposits since the arteries are on the sulci
Tau progression is different for CTE vs. AD (can tell the difference between the two
CTE: primarily in the cortex - where the sulci are
AD: seen in brainstem first, locus coeruleus, reticular activating system nuclei
Taupathies
Trying to develop PET tracer for CTE (tau) diagnosis in the living, but not there yet
There would be lots of tau in individuals with CTE
They found that the PET and post-mortem stain lined up pretty well
This tracer molecule for tau does not bind to tau equally well across the brain
Binds well in brain stem but not in cortex -> not useful for CTE
Cannot diagnose CTE with PET tau tracer
“Taupathy”
Result: neurofibrillary tangles
Infections of the brain
Some sort of microorganism thing is going in the brain
Bacterial infections
Bacteria are single-celled organisms
Can cause inflammation of the brain (encephalitis)
When bacteria attack the brain they often lead to the formation of cerebral abscesses (pus pockets)
Bacteria often attack the meninges, producing an inflammation known as meningitis
meningitis
Quite common
Might look like cold or flu: headache, stiff muscles, sensitivity to light or sound
In children: confusion, drowsy, irritable
Not clear what the problem is
Dangerous
Bacterial meningitis in humans adults is fatal about 25% of the time if not treated
Can be treated with antibiotics
BUT viral meningitis cannot be treated with antibiotics
In the news: convicted for using natural remedies to treat dying son, farther back promoting alternative medicine
They created natural products to treat illness
Their own 13-month son got sick: confused, irritable, drowsy, trouble maintaining consciousness
Son did not get better
They did not take their child to the hospital even though the child had meningitis
It was too late and their son died
Charged with criminal negligence
Bacterial infections: syphilis
Was a commonly passed on disease commonly by genital contact
Targets Nervous system tissue
Asymptomatic for years and syphilis will be on their skin
A type of bacteria that can attack the brain.
General paresis
Can treat with antibiotics, even later stages can use IV treatment
General paresis
the syndrome of psychosis/dementia that results from a syphilitic infection of the brain
Later stages of syphillis
Paresis: losing touch with reality, a form of psychosis
Hallucinations, delusions, loss of mental faculties
Around 15-20 years after infection of syphilis
