Brain and Spine Injuries in Infancy and Childhood

Question 1

While there is overlap b/w TMI injury on the brain and injury related to physical trauma, hypoxic-ischemic injury, hypoglycemia, hyperbilirubinemia, etc - what is a main difference?

Answer 1

TMI injuries tend to be progressive, while these other injuries typically are static - and a result of one or two well-defined events

Question 2

What are 3 specific end-stage patterns of tissue destruction after a defined injurious event:

Answer 2

• Porencephaly
• Hydranencephaly
• Encephalomalacia

Question 3

Patterns of brain injury: How do they change from fetus - neonate/infant - adult?

Answer 3

• Fetus
  
  • First 2 trimesters, does not mount an astrogiliotic response - instead, necrotic brain liquifies forming cysts.
• Neonate/Infant
  
  • In between fetus/adult - brain can mount a 15% response - will usually be cystic with septae.
• Adult
  
  • Encephalomalacia (soft brain), with gliotic lining - made up of astrocytes with a wall of reactive astrocytes.

Question 4

What is this? and what does it occur?

Answer 4

• Porencephaly (focal)
• Reponse to injury in the trimester fetus and neonate (doesn’t develop a reactive astrogliotic response) so instead of encephalomalacia/gliosis there is only liquifaction of necrotic brain with a smooth walled cyst.
• 3rd trimester fetus and Neonates can mount a response about 15% b/w 1st/2nd trimester fetus and adult.

Question 5

What is this?

Answer 5

• Porencephaly (presumed venous infarction)
• Smooth walled cystic cavity
• Can become part of the ventricle (as in this case). Try to differntiate from ex-vacuo ventricular dilatation if possible.

Question 6

What is this? Why does it develop?

Answer 6

• Hydrancencephaly​
• Really is diffuse porencephaly (likely from insult in 1st/2nd trimester)
• Diffuse liquifaction of cerebral mantle (gray & white matter)
• Sacs of CSF that enlarge - and are lined by 2 layers
  
  • thin outer leptomeninges
  • inner layer of remnant of G/W tissue and astrogliosis - but very thin.
• Small amount of inferior frontal/occipital white matter is spared
• Thalamus/Cerebellum usually spared
• Should try to differentiate from severe hydrocephalus (will be a rim of true G/W tissue)

Question 7

​Name 4 parts of the cerebral mantle that may be spared in hydranencephaly

Answer 7

• Inferomedial frontal lobe
• Inferomedial Occipital lobe
• Thalamus
• Cerebellum
• Falx is present.

Question 8

What is encephalomalacia

Answer 8

• Damaged brain with astroglial proliferation
• Surrounded by reactive astrogliosis “gliosis” - bright T2
• Can range from cystic to microcystic to non-cystic (from increasing to decreasing amounts of diffusivity) - although all encephalomalacia will show higher diffusivity than normal brain.

Question 9

What is this?

Answer 9

• Encephalomalacia
• Characterized by astroglial proliferation and reactive astrogliosis
• Abnormally increased T2 within injuried brain parenchyma with multiseptated/cystic areas - related to degerated brain.