Normal Development of the Neonatal and Infant Brain, Skull, and Spine

Question 1

Gyral development proceeds most rapidly in the area of:

Answer 1

Sensorimotor and visual pathways (same areas in which myelination occurs earliest, glucose uptake increases earliest, relative cerebral perfusion increases earliest, cortical microstructure matures most rapidly.

Question 2

In what portions of the brain is there late maturation (gyro development, myelination, metabolically)

Answer 2

Frontobasal, Frontopolar, Anterior Temporal regions

Question 3

True or false? Sulcal development occurs earlier in utero than ex utero?

Answer 3

True Sulci are seen earlier in fetuses still in the uterus than in neonates of similar postonceptional ages that have been born prematurely We don’t know why.

Question 4

Prenatal Cerebral Cortex Development: What are 4 areas of signal intensity seen before 24 weeks?

Answer 4

• Germinal Zone (low intensity rim around ventricles)
• Intermediate Zone (intermediate signal intensity adjacent to germinal zone - represents developing white matter full of axons and glial cells)
• Subplate (most T2 hyperintense) beneath the cortex, contains afferent thalamocortical axons waiting to move into the cortex to form synapses
• Cerebral Cortex
• (image from Bkvc)

Question 5

Terminal Zones - persistent areas of non-myelinated white matter along the lateral ventricles.

How long do they take to myelinate and why?

How are they different from WM injury of prematurity?

Answer 5

Can take up to 10 years (association areas of the parrietal/temporal lobes)

Differ from WM injury of prematurity - less well defined, layer of normal white matter b/w the ventricle. WM injury of prematurity should be lower, brigher, more well defined, and associated with volume loss (deeper gyri and decreased size of CC)

Question 6

T1 meylination points: Used up to 6 months

Splenium

Genu

Adult pattern minus most subcortical White matter

Answer 6

Splenium 4 months

Genu 6 months

Adult pattern minus most subcortical white matter - 8 months

Question 7

T2 myelination pattern: Used after 6 months

Splenium 6 months

Genu 8 months

Ant Limb of IC :

Entire brain minus subcortical by:

Answer 7

Ant Limb of IC: 11 months

Entire brain minus subcortical by 14 months.

Who brain by 30 months.