User Tools

Site Tools


dissection_carotid

internal carotid artery dissection

see also:

introduction

  • carotid dissection is an uncommon event occurring in ~2 in 100,000 population per annum
  • along with vertebral artery dissection, it accounts for ~20% of ischaemic stroke (CVA) in young adults
  • most common age is the mid-forties
  • extracranial carotid dissections typically occur >=2 cm beyond the bifurcation (at level of the skull base)
  • intracranial carotid dissections are most frequent in the supraclinoid segment
  • 10% are bilateral
  • 14% have aneurysmal dilatation

clinical features

risk factors

  • mechanical trauma in prior month - often minor (~30% cases)
    • sports, yoga
    • chiropractic neck manipulation
    • amusement park rides
  • Valsalva events:
    • childbirth
    • coughing
    • sneezing
    • sexual intercourse
  • predisposing factors:

Ix

  • if sudden onset headache, Mx initially as per suspected subarachnoid haemorrhage (SAH)
  • if clinical features suggest dissection then consider:
    • urgent MRA or CT angiography (both have similar sensitivity and specificity for dissection)
    • signs include:
      • long tapered arterial stenosis
      • a tapered occlusion
      • a dissecting aneurysm (pseudoaneurysm)
      • an intimal flap
      • a double lumen
      • an intramural hematoma

Rx

  • if acute ischaemic stroke (CVA) without subarachnoid haemorrhage (SAH) within 3-4hrs onset is present, consider thrombolysis - although this is quite controversial, may increase extension of the dissection, and risks may exceed the benefits
  • other patients with [stroke]] and without subarachnoid haemorrhage (SAH):
    • if large ischaemic area or intracranial dissection
    • if extracranial dissection and small stroke area and no SAH:
  • if extracranial, consider vascular opinion for repair or stenting, particularly if recurrent transient ischaemic attack (TIA) on antiplatelet Rx
  • avoid:
    • contact sports
    • chiropractic neck manipulation
    • any activity that involves abrupt rotation and flexion-extension of the neck

prognosis

  • extracranial carotid dissection:
    • >70% have excellent recovery
    • 10-25% have major disabling neurologic deficits
    • 5-10% die
    • most dissecting extracranial aneurysms do not resolve with angiographic follow-up
    • residual headache may indicate persistent vascular abnormalities
    • ~1% recur annually
    • 0.3% recurrent stroke risk per annum over next 4 years
    • 0.6% recurrent stroke risk per annum over next 4 years
  • intracranial carotid dissection:
    • ~33% have recurrence of neurologic events over next 8yrs
dissection_carotid.txt · Last modified: 2014/05/29 16:01 (external edit)