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Stroke

What is a Stroke? A stroke, also known as a cerebrovascular accident, is cerebral injury caused by an acute compromise of blood flow to the brain. Strokes are medical emergencies and require immediate assessment and treatment. Strokes are the leading cause of long-term disability and fourth leading cause of death in the Unites States. They also account for 50% of neurological hospitalizations.

Types of Stroke

Strokes are classified according to the mechanism by which the disruption of blood flow takes place. 

Ischemic Strokes account for most of the strokes and are caused by a blockage in a vessel that prevents adequate blood flow. Ischemic strokes can be caused by a few etiologies:

  • Thrombotic strokes stem from the development of atherosclerotic plaques leading to the formation of blood clots that can partially or completely obstruct the blood vessel affected. 
  • Embolic strokes are the consequence of obstructed blood flow by an embolus- a particle that has traveled in the bloodstream from another part of the body. Emboli can be blood clots, pieces of plaque, or air bubbles. 
  • Transient ischemic attacks (TIA) are caused by temporary blockages to blood flow that manifest as short-lived symptoms of a stroke but do not show evidence of a stroke on imaging. TIAs are indications of a high risk of a subsequent stroke and should be assessed urgently.
  • Cryptogenic strokes refer to strokes in which the cause, whether embolic or thrombotic, is unclear. Cryptogenic strokes make up one-third of ischemic strokes and half of them are caused by emboli from an unknown source.

Hemorrhagic strokes result from a rupture of a vessel, leading to bleeding into the surrounding tissue. The symptoms of hemorrhagic strokes are usually a consequence of the accumulation of the blood that irritates and causes inflammation of the surrounding tissue while increasing intracranial pressure. Hemorrhagic strokes can be classified as:

  • Intracerebral hemorrhages (ICH) occur within the brain and can be caused by traumatic injury, high blood pressure, and structural abnormalities in the blood vessels.
  • Subarachnoid hemorrhages occur in the subarachnoid space between pia and arachnoid membranes of the meninges. While subarachnoid hemorrhages may be caused by trauma, they usually result from the unexpected rupture of arteriovenous malformations or aneurysms

Risk Factors of Stroke

  • History of TIA
  • Previous history of clots
  • Age over 40 years
  • Family history 
  • Hypercholesterolemia
  • Hypertension
  • Diabetes Mellitus
  • Smoking
  • Obesity and sedentary lifestyle
  • Recreational drug use
  • Clotting disorders
  • Recent childbirth
  • Oral contraceptive pills
  • Weakness or abnormalities of blood vessels, such as aneurysms

Symptoms of Stroke

Classic symptoms of stroke include:

  • Facial drooping
  • Arm weakness
  • Speech difficulties

Other symptoms can include acute onset of:

  • Numbness or weakness of one side or limb of the body.
  • Confusion or problems with cognition.
  • Visual changes or loss.
  • Trouble with walking, balance, or coordination
  • Severe headache- this is especially characteristic of subarachnoid hemorrhages, which are often described as being the worst headache ever experienced.

Source: About Stroke. (n.d.). Www.Stroke.Org. Retrieved May 19, 2022, from https://www.stroke.org/en/about-stroke