Anatomy and patho

Cards (21)

  • Cerebrovascular accident (stroke or brain attack) is the 5th most common cause of death in Canada. The most effective way to decrease this burden is with prevention
  • Stroke occurs when there is ischemia to a part of the brain OR hemorrhage into the brain that results in death of brain cells
  • Functions controlled by the part of the brain with tissue death (left or right) are lost or impaired (eg: movement, sensation, emotions). The severity of the loss varies according to location and extent of the brain involved
  • The most common location for stroke is the middle cerebral artery. Other locations include the internal carotid artery or the vertebral artery.
  • Non modifiable factors
    • advanced age
    • gender
    • ethnicity
    • family history
    • prior TIA or stroke
  • Modifiable risk factors:
    • HTN
    • diabetes mellitus
    • atrial fibrillation
    • dyslipidemia
    • carotid stenosis
    • oral contraceptive use
    • smoking
  • Transient ischemic attack (TIA) is a transient episode of neurological dysfunction without acute infarction (cell death) of the brain. Symptoms typically last less than an hour but is a big risk factor for strokes
  • Types of stroke
    1. ischemic: can be thrombotic (clot formed in brain) or embolic (clot travels to brain)
    2. hemorrhagic (bleeding in brain)
  • Thrombotic strokes occur when a thrombus (blood clot) forms in diseased and narrowed blood vessel in the brain. It is often associated with HTN or diabetes
  • Embolic strokes occur when an embolus lodges in and occludes a cerebral artery. Heart conditions associated with emboli are atrial fibrillation and valvular prostheses
  • Hemorrhagic strokes result from bleeding into the brain tissue itself or into the subarachnoid space or ventricles. This happens through a cerebral artery aneurysm that bursts and releases blood
  • Hemorrhagic strokes are classified according to where the bleed is located. For examples a subarachnoid stroke is a bleed over the arachnoid meninge.
  • Stroke clinical manifestations
    • hemiplegia (paralysis) or hemiparesis (weakness)
    • impaired swallowing or gag reflex = dysphagia
    • numbness of face, arm or leg
    • visual disturbance = hemianopsia (loss of half the visual field)
  • The left side of the brain sees te right side of the world meaning that if the left side of the brain is damaged, your right visual field is affected
  • Stroke patients may experience aphasia (understanding) or dysarthria (speech) when a stroke damages the dominant hemisphere of the brain
  • Impaired communication
    • Broca’s aphasia: difficulty in expressing thoughts
    • Wernicke’s aphasia: difficulty understanding language
    • Dysarthria: disturbance of muscular control of speech
  • Intellectual clinical manifestations
    • difficulty controlling their emotions
    • exaggerated or unpredictable emotional responses
    • impaired memory or judgement
    • spatial perceptual: difficulty judging distances or neglect
  • Stroke pts may initially have urinary and bowel elimination problems
  • Motor deficits are contralateral (opposite) because motor pathways cross at the brain stem. A stroke affecting the left side of the brain will lead to motor deficits on the right side
  • Right brain damage manifestations
    • left side hemiplegia or neglect
    • spatial perceptual deficits
    • deny or minimize problems
    • rapid performance and short attention span
    • impulsive and impaired judgement
    • impaired time concepts
  • Left brain damage manifestations
    • right side hemiplegia
    • aphasias
    • slow performance, cautious
    • aware of deficits = depression and anxiety
    • impaired math and language comprehension
    • impaired right left discrimination