Global hypoxic-ischaemic injury

Case contribution: Dr Radhiana Hassan


  • An 18 years old boy with epilepsy
  • Recent admission for status epilepticus
  • Found unconscious at home, CPR by parents
  • In ED GCS=E1V2M2, also had 2 episodes of GTC seizures
  • Intubated and admitted to ICU
  • Poor GCS recovery after 10 days in ICU

CT Findings:

  • CT scan of the brain shows bilateral almost symmetrical hypodensities involving the basal ganglia.
  • The changes were not seen on previous CT scan done during admission.


MRI findings:

  • MRI shows signal abnormalities in both basal ganglia (yellow arrows) as noted on CT scan.
  • Subtle hyperintensities are also seen at cortical region of both occipital lobe (red arrows).

Diagnosis: Global hypoxic-ischaemic injury


  • also known as adult hypoxic-ischaemic encephalopathy
  • typically present following an acute event causing hypoxaemia or hypoperfusion such as near drowning, asphyxia, cardiac or respiratory arrest
  • primarily affects the grey matter structures; basal ganglia, thalami, cerebral cortex, cerebellum and hippocampi
  • As seen in this case, CT can be normal at early stage
  • CT findings include diffuse edema with effacement of the CSF-containing spaces, decreased cortical gray matter attenuation with loss of normal gray-white differentiation, and decreased bilateral basal ganglia attenuation
  • The reversal sign and the white cerebellum sign may be seen and indicate severe injury with a poor prognosis
  • Diffusion-weighted MR imaging is the earliest imaging modality to become positive, usually within the first few hours after a hypoxic-ischemic event.
  • T2-weighted images typically become positive during early subacute period (24 hours–2 weeks)
  • Gray matter signal intensity abnormalities at conventional MR imaging may persist into the end of the 2nd week.
  • In the chronic stage, T2-weighted images may demonstrate some residual hyperintensity in the basal ganglia, and T1-weighted images may show cortical necrosis


Author: radhianahassan