L5: Neuroanatomy P2 Flashcards
strokes and brain pathology does not discriminate, it also occurs in ____ structures
subcortical
BG contains 3 anatomical structures
caudate nucleus
putamen
globus pallidus
caudate nucleus + putamen of the BG from the
striatum
putamen and globus pallidus of the BG form the
lentiform nucleus
the nuclei of the BG participate in the control of _____ and _____, and _____/_____ movements
body posture
muscle tone
planning/initiating
the 2 functional units of the BG are
substantia nigra
subthalamic nucleus
axons from the substantia nigra in the _____ terminate in the ______ and _____ of the BG
midbrain
caudate n and putamen
axons from the subthalamic n interconnect with the _______ of the BG
globus pallidus
the internal capsule is sandwiched bw the thalamus and putamen/globus palidus - then there are radiation of projection fibres called _______, where someone may have a stroke
corona radiata
the main input unit of the BG is
striatum (putamen)
the main output unit of the BG is the
globus palidus
the BG is relayed to the ____ thamalus which connects to the SMA, and the _____ thalamus which connects to the PM1
anterior
lateral
BG is connected to the ______ which has incoming and outgoing fibres to the prefrontal cortex
caudate head
damage to BG will cause impairment in both
motor and cognitive linguistic
the thalamus is a collection of _______, and it acts as a ____ or ____ system
nuclei
relay or gating
the thalamus is rich with connections, such as afferent/efferent fibres from the _______ and _____ course through thalamus
cortex and brainstem/cerebellum
the thalamus is rich with connections, such as the peripheral system to the ______ and ______
thalamus
cerebral cortex
the thalamus is rich with connections, such as from the cortex to the _______ and back to the ______
thalamus
cortex
all neuronal communications involving sight, hearing, taste, and touch make a mandatory stopover at the thalamus except….
smell - olfactory information bypasses the thalamus prob bc of evolution (old sense and essential)
the cerebellum is below the _____ lobe and posterior to the _______, its made of ___ lobes and _____/____ matter
occipital
brainstem
2 lobes
grey/white
the cerebellum connects to what 3 major structures and communicates bw them?
brainstem
thalamus
cortex
cerebellum is responsible for
motor speech and cognitive linguistic functions
allows for the coordination and smoothness of skilled movements like speech prod (allows for more refinement)
why is the vascular supply important for the brain
blood supply must remain constant
supplies nutrients and oxygen which neurons and tissues need for viability
uses 15-20% of body’s blood (dont memorize)
Middle cerebral artery is important bc
it covers a large territory of the brain
the sylvian fissure is the main branch of the MCA
if there is a stroke to the MCA it can impact a lot involved in speech and cognitiont
watershed area is …
watershed stroke is when…
these strokes tend to be…
where two vascular distributions meet
water shed stroke is when something has gone wrong in one of the striate arteries
these strokes tend to be smaller and bc they are more distal to language areas the symps are usually of lesser intensity and/or duration
ischemia is
inadequate blood supply w neuronal and glial cell death
thrombotic =
blood cloth not travelling
ex. build up of plaque
embolic =
blood clot travelling
could also be travelling plaque
thrombotic/embolic make up what % of strokes
75-80%
hemorrhagic strokes result from
an aneurysm that has ruptured in the brain
transient ischemic attack aka a mini stroke is a high risk factor for
symps usually resolve in…
full stroke
10-30% in 1st year
30-60% in next 5 years
24 hours
aneurysm is…
pouching of an arterial wall - blood continues to flow and the wall will weaken and burst, the blood will fill that area of the brain - pushing neurons/structures around
arteriovenous malformation…
malformation of arteries/veins, they tangle up, if they tangle this may burst which will cause a hemorrhage
typically born w them
what occurs right after or soon after someone has a stroke in the area or around the area that it has occurred? (5 things)
local edema
diaschisis
infarction
transneuronal degeneration
denervation sensitivity
local edema is
edema meaning fluid
if you have an injury blood flow will inc and that will have plasma in it - now you have lots of fluid/inflammation at site of damage which will disaplace structures
diachisis is…
distant suppression of metabolic activity in regions connected w the area of stroke
infarction
loss of oxygen and other nutrient leads to neuronal death
transneuronal degeneration
degen of asscoiated neural areas due to loss of connection to infarcted area
aka if neurons are dead no info is being sent to the other neurons
denervation sensitivity
cells previously dependent on proper neuronal functions become supersensitive neurotransmitters and do not function normally
what are some non modifiable stroke risk factors? (7)
sex
age
cardiac arrhythmias
patent formamen ovale
family/medical history
genetics
heritage (indigenous/south asian/african)
what are some modifiable stroke risk factors? (10)
smoking
cholesterol levels
high blood pressure
diabetes
diet
obesity
heart disease
alcohol and drug use
hormonal contraceptives
invitro fert
coup and contra-coup for a TBI refers to
coup = initial site of injury
contra-coup = the side the brain bounces back on
open vs closed TBI
open = ex. gun shot
closed = ex. concussion
during a TBI, bony interior structures tear….
delicate neurons, fibers, tracts, fasciculi even w/i CSF ad meningeal layers
forces that occur during a TBI include
shearing, tearing, rotational, accelerating, decelerating and torsional forces
TBIs cause…
ischemia, edema, hemorrhages, and infections
TBIs may cause post traumatic _____, which 2 types…
amnesia
anterograde and retrograde
anterograde amnesia
post onset
not being able to encode and retrieve memories - hard to work with clinically
retrograde amnesia
prior to onset
not being able to pull up memories from prior to the injury
sub dural hematoma is…. how could it be treated?
blood under the dura matter
if this blood is not reabsorbed then there may be a hole drilled into the cranium to remove the blood or a portion of the skull removed to allow the brain to expand
neuroplasticity =
the brain’s capacity to change in response to enviro changes or changes in the organism itself
the changes in brain activity associated w the tasks performed in an attempt to compensate for impaired functions
microlevel neuroplasticity is…
neural plasticity
cellular (biochemical and physiologic) - ex. neurons, supporting glial cells
structural - ex. changes to meninges, blood supply
macro level neuroplasticity is
behavioural plasticity aka functional level
neuroplasticity can be ______ or compensatory, ______ or maladaptive
restorative
adaptive
how could neuroplasticity be adaptive and maladaptive in terms of if there was damage to the L inferior frontal gyrus?
Homologous = if there is damage to left inferior frontal gyrus bc of stroke, now the right inferior frontal gyrus is going to help out – this can be adaptive, but if the rght takes over on a more permanent basis this could become maladaptive bc this region wasn’t intended for this function in the first place – Mal adaptiveness could be seen as inefficiency
microlevel (neural plasticity) in terms of recovery would be…
restoration of a function w/i an area of the cortex initially lost post injury
microlevel (neural plasticity) in terms of compensation would be…
diff neural tissue takes over the function lost after injury
macrolevel (behavioural plasticity) in terms of recovery would be…
capacity to perform a previously impaired task in the same manner as before the injury
macrolevel (behavioural plasticity) in terms of compensation would be…
the use of a new strategy to perform the same task
spontaenous (natural) recovery in terms of stroke damage is the …
period of time in which non-damaged regions made non-functional temporarily due to edema, changes in blood flow, metabolic changes, medical status etc, resume function
a time period in which damaged parts are no longer damaged
the acute stage post stroke is…
hours to 30 days
reperfusion of damaged brain area(s) (spontaneous or deliberate i.e. tPA/TNK)
reduced edema and metabolic disturbances, and restoration of tissue function
the subacute stage post-stroke is…
30 days to 6months (initial few weeks)
neural reorganization (establishment of alternative networks)
resolution or regression of diaschisis
axonal sprouting and activation of latent synapses
the chronic post-stroke stage is…
6+ months (months to years)
compensatory reorganization of language (behavioural +/- neural plasticity….. aka at both micro and macro level)
rate of recovery is greatest up to ______ post stroke, BUT longstanding ______ recovery is possible
6 months
language
activation of latent synapses is….
when adjacent areas may help out even if its not their designated function – some resolution of function but may not be as efficient as it once was
penumdrum is…
the area around the core of the stroke that reps an area of hypoperfusion – so a lesser amount of blood is getting to this area – best case scenario is that the penumdrum will be treated so that profusion of blood can be resolved (will be left with a more focal area of injury)
what are the 6 neurological prognostic factors of recovery?
etiology
lesion size
lesion site
APHASIA SEVERITY
aphasia type
linguistic abilities
what are the 8 individual prognostic factors of recovery? (3 biological and 5 social)
age
sex
handedness
education/premorbid intelligence
social milieux/occupation
psychological issues
personality/emotional status
bilingualism
etiology of strokes: __________ curve for ischemic strokes, ______ for hemorrhagic and TBI, _______ curve for neurodegen disease
negative accelerating curve for ischemic
stair step for hemorrhagic and TBI
negative declining curve for neurodegenerative diseases
in terms of lesion size and site of a stroke, damage to sensitive regions will result in…
slower language recovery
in terms of lesion size and site of a stroke, damage to wernicke’s area =
poor prognosis
bc of auditory comprehension (makes it hard to work in therapy w indvs)
aphasia severity at onset is the ______ prognostic neurological factor
most important
potentially single most influential factor
Remains the most potent prognostic factor! - aka if you have severe aphasia at onset your prognosis is worse than someone who has less severe aphasia at onset
in terms of aphasia type, global aphasia is …
severest form of aphasia, poorest recovery profiles
in terms of aphasia type, anomic aphasia is …
best recovery profiles
in terms of aphasia type, non fluent vs fluent …
nonfluent better prognosis than fluent (check!!!!)
in terms of time post-onset, there will be poorer recovery the longer _______ is delayed
language and communication recovery
in terms of time post-onset, delayed recovery does not capitalize on…
synergistic effects of acute and subacute spontaneous recovery
in terms of time post-onset, starting recovery later could be beneficial but…
not the same extent as starting earlier
We want to capitalize on spontaneous recovery! - there are things we can do on a therapeutic level to intervene
good auditory comp, writing, verbal skills, visual matching is known as a …
good recovery profile (at baseline)
other positive prognostic factors related to linguistic abilities are…
initial auditory and reading comp scores/skills
stimulability for correction
self correction
gestural abilities (strong = good)
younger = ____ outcome, ____ correlation tho when other factors controlled
improved
poor
women _____ aphasic or _____ recovery bc of ….
less
better recovery
bc of interhemispheric vs intrahemisphere connectivity
One consideration is that are women less aphasic to begin w or is it that we are wired differently, women have more hemispheric conncectivity compared to men (does this allow for more reorganization/taping into homologous areas)
more research needed
left-handed or ambidextrous correlated w _____ recovery
improved
possibly bc of inc hemispheric connectivity
age, sex, and handedness are overall…
not good or consistent predictors of recovery for aphasia
higher education levels =
better recovery
but they still may not catch up to where they once were
higher intelligence =
better chances of good recovery
in terms of prognosis, social millieux and occupation(s) are…
helpful and supportive for prognosis but not overly impactful on language scores; limited data
there is _____ prognosis in co-presence of sensory (ex. visual cuts), motor limb and motor speech (i.e. AOS), medical, and psychiatric (i.e. depression)
poorer
extrovert vs introvert in terms of prognosis …
not a lot of data to support effects on recovery
post-aphasia disinhibition may influence recovery bc…
Ex. Someone w a more frontal lobe issue they may have issues w inhibition – they do not do as well w their recovery
co-occuring depression (ex. in Broca’s) can influence recovery _____
negatively
bilingualism’s effect on recovery ….
mixed and unclear findings about influence on aphasia recovery
what are the 5 therapy options?
speech and language
pharmacotherapy
stem cell
rTMS/tDCS
computer based language
what is the optimal delivery of speech therapy during acute/sub acute stages?
intense weekly interventions range up to 8.8 to 13 hours/week for 11 to 12 weeks
R-hemispheric activation alone associated w _____ outcomes indicating a need for and role of …
worse
L-hemisphere in recovery
aka if the L-hemisphere doesn’t jump in at some point the prognosis is worse
tissue plasminogen activator aka IV tPA and TNK is…
the only USA FDA approved treatment for ischemic strokes
dissolves clots and improves blood flow
must be used w/i first 4.5 hours of onset of ischemic stroke
endovascular thrombectomy is
when a clot is removed surgically and improves blood flow
6 hour time window for most patients
The ultimate goal to facilitate recovery is to….
develop a model of behavioural therapy based on …
- specific neuronal plasticity mechanisms (ex. the recruitment of the right hemisphere)
- influential neurological and indv recovery factors
use it or lose it =
failure to drive specific brain functions can lead to functional degradation
use it and improve it =
training that drives a specific brain function can lead to an enhancement of that function
ex. swallowing = if someone is on a tube feed you need to reintroduce them to food/drink
specificity (plasticity consideration) =
the nature of the training experience dictates the nature of the plasticity
ex. need to target what you want to improve
repetition matters (plasticity consideration) =
induction of plasticity requires sufficient repetition
intensity matters (plasticity consideration) =
induction of plasticity requires sufficient training intensity
time matters (plasticity consideration) =
different forms of plasticity occur at diff times during training
salience matters (plasticity consideration) =
training experiences must be sufficiently salient to induce plasticity
ex. more tailored the stimuli to the patient the more salient the therapy
age matters (plasticity consideration) =
training inducted plasticity occurs more readily in younger brains
transference plasticity (plasticity consideration) =
plasticity in response to one’s training experiences can enhance the acquisition of similar behaviours
interference (plasticity consideration) =
plasticity in response to one’s training experiences can interfere w the acquisition of other behaviours
