Differential diagnosis of premature brain injury

• Injury in the perinatal period
  — In-utero neonatal intraventricular hemorrhage
  — Neonatal intraventricular hemorrhage grade I-III
  — Periventricular hemorrhage / intraventricular hemorrhage grade IV
  — Periventricular leukomalacia
• Injury in later life
  — Focal parenchymal loss due to periventricular hemorrhage or periventricular leukomalacia = porencephalic cyst
  — Diffuse white matter loss due to periventricular leukomalacia

Approach to the differential diagnosis of premature brain injury:

• Neonatal intraventricular hemorrhage grade I can develop in utero and present after birth as a resolving subependymal cyst in the germinal matrix
• Neonatal intraventricular hemorrhage grade I-III is confined to the germinal matrix and the ventricular system and has an etiology distinct from…
• …Periventricular hemorrhage (also known rather mistakenly as neonatal intraventricular hemorrhage grade IV) which is a wet (hemorrhagic) infarct and is most commonly unilateral
• Periventricular leukomalacia is a dry (ischemic) infarct and is most commonly bilateral