ISCHEMIC STROKE / CLASSIFICATION AND ETIOPATHOGENESIS

Dolichoectasia

Created 27.01.2020, last update 16.12.2021

  • a progressive disease characterized by dilatation + tortuosity of the arteries; sometimes called dilated arteriopathy
    • the vertebrobasilar artery is most commonly affected (⇒ vertebrobasilar dolichoectasia or megadolichobasilar artery)
    • ICA is also at high risk of being affected
  • incidence 0.06-6% [Brutto, 2021]
  • poses an increased risk of stroke recurrence (up to 19%/2 years) [Chen, 2019]
  • may cause some “cryptogenic” strokes [Brutto, 2021]
  • the characteristics listed below also apply to large fusiform aneurysms

Pathophysiology

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Etiology

  • atherosclerosis (atherosclerotic dolichoectasia)
    • affects both intracranial and extracranial arteries
    • usually age > 40 years
    • typical vascular risk factors (e.g., hypertension) are present
  • congenital disorders  (non-atherosclerotic dolichoectasia)
    • age < 40 years, more common in women, distal branches of the posterior circulation are affected
    • Marfan syndrome, Ehler-Danlos, Fabry disease
  • dolichoectasia secondary to dissection

Clinical presentation

  • ischemic stroke/TIA (30%/5y)
  • intracranial bleeding, subarachnoid hemorrhage
  • brainstem compression (basilar dolichoectasia), hydrocephalus
  • neurovascular compression syndrome (NVCS)
    • compression of the optic nerve at the optic chiasma (ICA)
    • impairment of one or more cranial nerves is associated with a tortuous and elongated BA (n. VII, VIII, VI)
  • factors affecting the clinical outcome:
    • severity of arterial dilation and lateral shift
    • signs and symptoms at the time of the diagnosis
    • presence of mural thrombi
    • ectasia progression on follow-up imaging

Diagnostic evaluation

  • CTA/MRA/DSA
    • enlargement and kinking of the artery with lateral shift
      • basilar arterial diameter > 4.5 mm
    • sometimes intraluminal thrombi can be detected
    • distinguish fusiform aneurysm   Fusiform aneurysm on basilar artery (CTA)
  • neurosonology
    • decreased flow velocity
Dolichoectasia of basilar artery on MRA
Basilar artery dolichoectasia (CTA)

Dolichoectasia of basilar artery on CTA

Management

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Prognosis

  • from asymptomatic to malignant forms
  • progression is more common in younger patients with ectasia in the anterior circulation
  • a relatively high risk of stroke recurrence (up to 60% / 11 years)
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