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Ischaemic Stroke classifications

Learning objectives

  • Learning
  • Understand
  • Integrate
  • Reflect

There have been attempts to classify strokes beyond the simple differentiation into infarctions and haemorrhagic. Each attempt has its own particular uses whether based on cause or clinical findings. The TOAST classification shown below has been well reference as it introduced a well quoted stroke classification. It would be wise to have heard of it. TOAST trial ( Trial of Org 10172 in Acute Stroke Treatment).

TOAST classification
  • large-artery atherosclerosis
  • cardioembolism
  • small-vessel occlusion
  • stroke of other determined aetiology
  • stroke of undetermined aetiology

The number of different mechanism involved in stroke are significant and are listed below. These will be dealt with in more detail in the next chapter.

Some of the many Pathological Processes involved in Stroke
  • Atherosclerosis : intracellular collections of lipid within smooth muscle cells and macrophages.
  • Arteriosclerosis: small vessel disease affecting arterioles associated with hypertension. Sub-endothelial hyaline (from mucopolysaccharides and matrix proteins) collection and Lipohyalinolysis which can lead to a weakened vessel and formation of small aneurysms. This can lead to either vessel obstruction or bleeding.
  • Thromboembolism: Plaque rupture and partial or total vessel occlusion by thrombus can then embolise and cane a much more distal obstruction downstream.
  • Amyloid deposition
  • Fibromuscular dysplasia
  • Vasculitis: Giant cell arteritis, Primary Angiitis of the CNS
  • Infiltration/Deposition: Sarcoid, Fabry's disease, CADASIL
  • Migraine - cortical spreading depression
  • Connective tissue disease : intimal dissection/haematoma formation
  • Thrombophilia - malignancy, inherited or acquired defects
  • Thrombocytosis
  • Berry aneurysm - SAH
  • Arteriovenous malformation - SAH and intracerebral haemorrhage
  • Cavernous haemangiomas - SAH and intracerebral haemorrhage
  • Vasospasm - Cocaine/SAH
  • Cardioembolism: Endocarditis