Stroke Flashcards
Ischemic Stroke
- This is the most common type and occurs when a blood clot blocks or narrows an artery leading to the brain. This type can further be divided into:
- Thrombotic Stroke: Caused by a blood clot that forms in one of the arteries supplying blood to the brain.
- Embolic Stroke: Occurs when a blood clot or other debris forms away from the brain, commonly in the heart, and is swept through the bloodstream to lodge in narrower brain arteries.
Hemorrhagic Stroke
- This occurs when a blood vessel in the brain bursts, leading to bleeding in or around the brain. There are two types of hemorrhagic strokes:
- Intracerebral Hemorrhage: The most common type of hemorrhagic stroke, occurs when an artery in the brain bursts, flooding the surrounding tissue with blood.
- Subarachnoid Hemorrhage: Bleeding in the area between the brain and the thin tissues covering it.
Transient Ischemic Attack (TIA)
often called a mini-stroke. A TIA is a temporary period of symptoms similar to those of a stroke. A TIA doesn’t cause permanent damage and is often a warning sign for a future stroke.
* major risk factor for disabling stroke
* 13 fold icnreased risk of CVA in a year
* symptoms may only last few mins
Symptoms of Stroke
- Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body.
- Sudden confusion, trouble speaking, or difficulty understanding speech.
- Sudden trouble seeing in one or both eyes.
- Sudden trouble walking, dizziness, loss of balance, or lack of coordination.
- Sudden severe headache with no known cause.
What is the penumbra?
Region of the brain that is between areas that are dying & areas that receive enough blood to communicate.
* Made up of ischemic brain tissue that has enough energy to survive for a shoft time but not enough to function or communicate
* it is unstable in both time and space
* Can be reversible or irreversible
It is important because:
* early recsue is key for treating ischemic stroke
* can be salvageable if perfusions is improved rapidly
Risk Factors (Ischemic)
- Cardiac disease
- history of hypertension
- diabetes
- hypercholesterolaemia
- TIA
- Smoking
- Mitral stenosis
- Obesity & low PA
- Age, gender, hereditary, race, geographic location
Risk Factors (Hemorrhagic)
- Anticoagulation
- hypertension
- heavy drinking
- illegal drug use (coke and meth)
- thrombolytic therapy
- age, race, amyloid angiopathy
Pathology of Stroke
- Brain requires constant supply of O2 & glucose via cerebral arteries to function
- Stroke interrupts normal cerebral blood flow, can lead to brain cell damage or death
- If blood flow drops below critical level, affected neurones will die and be unable to regenerate
- Brain tissue ischemia, nerve cell function ceases after 1 min. after 4 mins, irreversible cell death occurs
Frontal lobe function & dysfunction
Function
* motor, personality/mood, intellect, working memory & recall, speech
Dysfunction
* muscle weakness, altered muscle tone, decreased voluntary control, personality/mood changes, memory issues, expressive dysphasia, issues with higher executive function, dyspraxia
Occipital Lobe function & dysfunction
Function:
* Vision
* Whole object integration/imaging
Dysfunction:
* Issues with visuospatial awareness, diplopia
Temporal lobe function & dysfunction
Function:
* Auditory ability, naming of objects, formation & management of memory, visual recognition
Dysfunction:
* Deafness, agnosia, prosopagnosia, inability to form new memories, receptive dysphasia
Parietal lobe function & dysfunction
Function:
* sensation, speech, understanding & concentration
Dysfunction:
* altered sensation, neglect, issues with understanding & concentration
Cerebellum function & dysfunction
Function:
* coordination of voluntary movement such as posture, balance, coordination & speech, resulting in smooth & balanced muscular activity
* important for learning motor behaviours
Dysfunction:
* ataxia
Brainstem function & dysfunction
Function:
* conduction of info to/from body to cerebrum & cerebellum
* emergence of cranial nerves that supply the face, head, viscera
* cardiovascular system control
* respiratory control
* alertness
* pain sensitivity control
* awareness
* consciousness
Dysfunction:
* alteration to function of cranial nerves: visual disturbances, pupil abnormalities, changes in sensation, muscle weakness, hearing issues, vertigo, swallowing & speech issue, voice change, coordination issue, locked in syndrome, death
Basal ganglia function & dysfunction
Function:
* selection processor
* filters info & selects appropriate response in relation to novel & well learned movements
* involved in planning, initiating, execution of movement
Dysfunction:
* Involuntary movements, bradykinesia, increased muscle tone, muscle rigidity, tremor, memory loss, problem finding words, uncontrollable repeated movements/speech/tics
