Pathology of stroke

Cornell notes

Stroke Pathological View – Cornell Notes

🌟 Cues

Definition of Stroke
Risk Factors (Modifiable & Non-modifiable)
Pathophysiology of Stroke
Types of Stroke (Ischemic vs Hemorrhagic)
Repair Mechanisms

🗒 Notes

Definition:

A stroke is a sudden onset of a focal neurological deficit caused by a pathological process in the blood vessels, often due to ischemia or hemorrhage. The brain, although only 1-2% of body weight, receives about 15% of resting cardiac output and consumes 20% of the body’s oxygen.

Epidemiology:

750,000 cases annually in the USA.
Prevalence is increasing drastically in Saudi Arabia (29/100,000/year).
Third leading cause of death globally, with a mortality rate of 25% within a year of the first stroke.

Risk Factors:

Non-modifiable: Age (doubles every decade after 55), gender (higher mortality in women), race (higher incidence in African Americans, Hispanics, Asians), family history.

Modifiable: Hypertension, smoking, high cholesterol, diabetes, obesity, and physical inactivity.

Pathophysiology:

The primary cause of ischemic stroke is atherosclerosis, where plaques form in arteries leading to occlusion. This leads to hypoxia and eventual cell death, particularly in neurons, which are highly sensitive to oxygen deprivation.

Key stages in ischemia: Loss of ATP production, excitotoxicity from excess glutamate, and free radical formation.

📝 Summary

A stroke occurs when blood flow to a part of the brain is blocked or when a blood vessel bursts, leading to brain cell death. The condition is a major cause of death and disability worldwide. Stroke risk increases with age, and while some factors such as age and family history are non-modifiable, lifestyle changes like managing blood pressure and cholesterol levels can significantly reduce risk.

The pathophysiology of stroke involves a complex cascade of cellular events, including hypoxia, excitotoxicity, and free radical damage. Treatment focuses on preventing further damage and promoting repair, with mechanisms like neurogenesis, angiogenesis, and glial scarring playing key roles in recovery.