ICL 3.0: Pediatric Brain Imaging Flashcards
when does the neural tube close?
completed by 28 days of gestation
what is prosencephalization? when does it happen?
formation of the cerebral hemispheres and diencephalon
1-2 months gestational age
when does neuronal proliferation happen?
2-4 months gestational age
when does neuronal migration happen?
3-5 months gestation –> so if moms are exposed to a virus or something around this time it can lead to problems
it’s when the neurons start moving to the cerebral cortex
this is what leads to gyrus and sulcus formation!
when do gyrus and sulcus formation happen?
5-9 months gestation
when does neuronal organization and myelination happen?
3rd trimester through the 2-3rd decades of life!!!
by around 36 weeks gestation, the vast majority of neuronal proliferation is complete
neurons begin to grow and form synapses with other neurons to form neural networks
when is the most rapid period of myelination?
Myelination begins early in the 3rd trimester but the most rapid period of myelination is the first 2 years of life
if you notice, this parallels important developmental milestones!!
what is the pattern of myelin formation? QUIZ QUESTION
- myelination starts centrally from the brain stem and out to the periphery –> because think about it, a baby can only do basic tasks like being breathing, feeding, heartbeat etc.
- it goes caudal to rostral so brainstem to the cortex
- it goes dorsal to ventral so occipital to frontal
- sensory then to motor
what’s the difference between T1, T2 and T2 FLAIR MRI?
T1 has dark CSF and white myelin
T2 and white CSF and dark myelin
T2 FLAIR looks a lot like T1 because unmyelinated white matter is dark; as the myelin forms it becomes immature myeline which will look bright BUT then as the myelin matures the myelin turns dark = triphasic pattern
what is the perirolandic region?
pre and post central gyrus
why can’t 6 month olds walk if they have myelin in the corticospinal tract and posterior limb of the internal capsule of the brain?
they don’t have peripheral myelination yet! their legs and arms don’t have any myelin
