Lecture 4: Stroke and Related Conditions

age, gender, race, heart disease, diabetes, prior stroke

non-modifiable stroke risk factors (6)

smoking, obesity, hypertension, high cholesterol, diet, physical inactivity

modifiable stroke risk factors (6)

clots formed by plaque development in vessel wall, occurs gradually over several days

ischemic: thrombotic CVA

clots that dislodge from site of origin and travel to a cerebral blood vessel

ischemic: embolic CVA

mini stroke, lasts less than 24 hours, similar symptoms, warning for more TIA’s or stroke

transient ischemic attack

rupture of small perforating arteries that supply deep cerebral structures

hemorrhagic CVA: intracerebral/interparenchymal hemorrhage

aneurysm, arteriovenous malformation

conditions that could potentially result in hemorrhage (2)

balloon-like swelling of arterial walls, can rupture and result in hemorrhage

aneurysm

congenital malformation, group of blood vessels form incorrectly and become tangled, form direct connection and bypass normal tissues

arteriovenous malformation

location of occlusion, size of vessel, time

3 factors impacting stroke severity

possibility of adequate collateral circulation, could lead to less damage

location of occlusions impact on severity: within or proximal to Circle of Willis

collateral circulation is less adequate, typically results in localized death of tissue (infarct) in predictable territory

location of occlusions impact on severity: distal to Circle of Willis

size of infarct is related to size of occluded vessel

size of vessel occluded: impact on severity

area surrounding an ischemic event (thrombotic or emolic)

penumbra

blood flow and oxygen transport is reduced locally, leading to hypoxia of the cells

how does a penumbra area occur?

amplifies original damage from ischemia

penumbra: possible result of cell death

may remain viable after an event due to collateral arteries supplying penumbral zone

salvaging/protection of penumbra area

decreases

penumbra area _____ with time

protect penumbra aea and increase oxygen delivery to the cells to limit cell death

penumbra: goal in the ED

salvage of the cells is possible

the existance of a penumbra implies…

idea that the brain can change or reorganize itself in response to internal or external stimuli

neuroplasticity

other areas of the brain assume the functions of damaged areas

when/how does neuroplasticity occur?

severity of neurological damage, age, premorbid health status, preinjury use of damaged brain area

neuroplasticity is dependent on the following…(4)

posterior, anterior, limbic

3 multimodal association areas

where the temporal, occipital, and parietal lobes meet

posterior multimodal association area: location

integrates sensory information

posterior multimodal association area: function

prefrontal cortex

anterior multimodal association area: location

uses integrated sensory information from posterior MMAA to make decisions about which motor plan to implement

anterior multimodal association area: function

inferior surface of the parietal, temporal, and frontal lobes

limbic multimodal association area: location

uses integrated sensory info from posterior and anterior MMAAs and links it to emotions and motivations through memory

limbic multimodal association area: function

controls motor function and receives sensory information of left side of body, perception of oneself in the environment, abstract and creative interpretation of information, interprets verbal tone and gestures

right hemisphere functions (4)

controls motor function and receives sensory information of right side of body, language interpretation and expression, controls concrete functions that can be easily observed/measured

left hemisphere functions (4)

visual perceptual disorder, inability to identify/recognize familar objects and people while visual anatomy is intact

visual agnosia: type of condition and definition

visual-spatial perceptual dysfunction, difficulty understanding the concept of right and left

right/left discrimination: type of condition and definition

visual-spatial perceptual dysfunction, difficulty distinguishing foreground from background

figure-ground discrimination: type of condition and definition

visual-spatial perceptual dysfunction,difficulty attending to subtle variations or changes in form

form-constancy: type of condition and definition

visual-spatial perceptual dysfunction, diffiuclty comprehending the relationship of one location to another

topographical disorientation: type of condition and definition

visual-spatial perceptual dysfunction, diffiuclty with concepts related to positions/directional terms

position in space: type of condition and definition

visual-spatial perceptual dysfunction, difficulty determining whether one object is closer to the individual when compared to another object

depth perception: type of condition and definition

tactile, proprioceptive, and pressure sensory, reality

body schema: severe discrepency between what types of input (3) and ____?

body schema perceptual dysfunction, inability to integrate and use perceptions from one side of body or environment

unilateral neglect: type of condition and definition

body schema perceputal dysfunction, extensive neglect and failure to recognize ones own body paralysis

anosognosia: type of condition and definition

right

anosognosia results from lesions to which hemisphere?

language perception dysfunction, impairment in the comprehension of language

receptive aphasia: type of condition and definition

language perception dysfunction, impairment in ones ability to express clear and meaningful langauge

expressive aphasia: type of condition and definition

perceptual motor dysfunction, difficulty understanding the motor demands of a task (sequencing, correct use of objects, etc)

ideational apraxia: type of condition and definition

conception

ideational apraxia results from a breakdown in the ______ stage

perceptual motor dysfunction, difficulty accessing and implementing the motor plan of a task

ideomotor apraxia: type of condition and definition

execution

ideomotor apraxia results from a breakdown in the ____ stage

perceptual motor dysfunction, form of ideomotor apraxia, difficulties dressing oneself

dressing apraxia: type of condition and definition

perceptual motor dysfunction, inability to copy 2 and 3 dimesional designs or models

2-D and 3-D constructional apraxia: type of condition and definition

tactile perceptual dysfunction, inability to interpret sensations through touch

tactile agnosia: type of condition and definition

tactile perceptual dysfunction, difficulty attaching meaning to somatosensory data

cortical sensation: type of condition and definition