Carotid Artery Disease

• What is it?
• How is it diagnosed?
• Who are at risk?
• What is the treatment?

What is it?

Carotid arteries (left and right) situated inside the neck are responsible for majority of the blood supply to the brain. The common carotid artery branches into two arteries
 

• the internal carotid artery that goes into the brain
• the external carotid artery that supplies the head and face.

Atherosclerotic disease commonly affects the carotid bifurcation. Atherosclerotic plaques deposited over the inner surface of the artery causes narrowing (stenosis) of the vessel.
 

• Small fragments of the atherosclerotic plaque may break off and pass along the artery into the smaller vessels inside the brain.
• This causes transient ischaemic attack or stroke (see below).
• Studies showed around 20% -30% of all strokes in the population are related to carotid artery disease.
• The possibility of fragments released from the plaque depends on
   
  • the severity of the atherosclerotic disease (ie degree of narrowing/stenosis of the carotid artery)
  • the composition of the plaque.

Transient Ischaemic Attack (TIA) and Stroke

Transient Ischaemic Attack (TIA): occlusion (closure or blockage) of blood vessel of the brain causing lack of blood supply (ischaemia) to the brain cell for a short period of time.

• When the blood vessel get obstructed, the body will try to correct it by either of the following methods:
  • dissolving the obstructed lesion with blood components 
  • dilating the other vessel that supply the same region of the brain so as to prevent permanent brain cell death.

• If the salvage is successful, patient will experience temporary neurological symptoms including
  • numbness
  • tingling sensation
  • weakness of one side of the body
  • loss vision over one eye
  • one sided facial weakness
  • speech difficulty

• Symptoms usually resolved within 24 hours.

Stroke (ischaemic): occlusion (closure or blockage) of the blood vessel of the brain and cannot be corrected by the body resulting in permanent brain cell death over certain region. }

• The symptoms are similar to Transient Ischaemic Attack but they persist beyond 24 hours.
• Occlusion of a major blood vessel in the brain will result in a large area brain cell death and could be fatal or severely disabling.
• Patients' disability after stroke can be improved by rehabilitation exercise as the surrounding viable brain will take over part of the work of the ischaemic brain cells.

Stroke is the third most common cause of death and the leading cause of disability in many developed countries.