Posterior inferior cerebellar artery (PICA) infarct

Posterior inferior cerebellar artery (PICA) occlusion may cause infarction of any of the vascular territory of the PICA, namely the posterior inferior cerebellum, inferior cerebellar vermis and lateral medulla.

Typically considered the most common territory involved in cerebellar infarction, although at least one study 1 has demonstrated similar frequencies of PICA and SCA infarcts.

Vertigo, nausea and truncal ataxia are the most common presenting features. Signs of a lateral medullary syndrome may coexist in ~30% 2

Headache and neck pain are normally the result of full PICA tertiary infarcts and represent swelling and mass effect 3. There are multiple eponymous posterior stroke syndromes, often presenting incompletely 4. Variations are common and the PICA syndrome for example, often present with facial pain as the initial symptoms and hypoalgesia, affecting either side of face 5.

As with all cases of suspected stroke, CT or MRI is required urgently to exclude hemorrhagic stroke. CT angiography should be utilized if the patient fits thrombolysis therapy guidelines 6. MRI angiography and CT angiography both have very high sensitivity for vessel occlusion identification, at 87% and 100% respectively 7. MRI is far more superior to CT in the sensitivity of acute ischemic stroke across all vascular territories. In the first twenty-four hours, studies show approximately 75-95% sensitivity for MRI diffusion weighted images, compared to CT of 16% 8.

Treatment of PICA and posterior circulation strokes in general, depend upon the nature, timing and severity of symptoms. If timing of diagnosis fits within the 4.5 hours of onset of symptoms, then thrombolysis can be used 9. Acute endovascular therapies, often in the form of lysis or clot removal, can be used, particularly in basilar artery occlusion 10. In large volume cerebellar infarcts, neurosurgical treatment with decompression or external ventricular drainage can be lifesaving in patients who have acute hydrocephalus or raised intracranial pressure causing reduces consciousness 11. In PICA infarction, the outcomes are generally expected to be good 12.


Stroke and intracranial haemorrhage
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Article information

rID: 19247
Section: Gamuts
Tag: stroke
Synonyms or Alternate Spellings:
  • PICA infarct
  • Posterior inferior cerebellar arterial infarct
  • Posterior inferior cerebellar artery (PICA) infarction
  • Posterior inferior cerebellar artery infarction
  • Posterior inferior cerebellar arterial infarction
  • PICA stroke
  • PICA infarction

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Cases and figures

  • Figure 1: vascular territories
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  • Case 1
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  • PICA infarct
    Case 2
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  • Case 9
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