Development of the Nervous System & Clinical Correalates in Padiatrics - Part 2

Question 1

In general terms what is the overall role of the prenatal and then postnatal periods in brain development ?

Answer 1

• Prenatal - serves to establish the core components of the CNS
• Postnatal - the mature organisation of the brain

Question 2

How does enrichment and deprivation affect brain development ?

Answer 2

Basically in postnatal kids if an eye is blocked for some reason it can cause the bands or coloums representing the deprived eye to shrink and also alter patterns organisation within the primary visual cortex. This can result in poor vision in the affected eye or blindness i think.

Question 3

What are some of the things that can cause defects and affect development ?

Answer 3

• Faulty genes, chemical messaging and glial guides
• Intrauterine insults
• Extrauterine insult and exposures
• Timing

Question 4

What is anencephaly ?

Answer 4

A severe congenital condition in which a large part of the skull is absent along with the cerebral hemispheres of the brain.

Question 5

What is spina bifida ?

Answer 5

A congenital defect of the spine in which part of the spinal cord and its meninges are exposed through a gap in the backbone. It often causes paralysis of the lower limbs, and sometimes learning difficulties

Question 6

What is holoprosencephaly?

Answer 6

Disorder in which the prosencephalon (the forebrain of the embryo) fails to develop into two hemispheres.

Question 7

What condition is shown here ?

Answer 7

Holoprosencephaly

Question 8

What are some of the disorders of myelination ?

Answer 8

• Hypomyelination
• Dysmyelination
• Demyelination

Question 9

What does the PLP1 gene do?

Answer 9

Encodes for the predominant myelin protein present in the CNS. Responsible for compaction, stabilization, and maintenance of myelin sheaths, oligodendrocyte development and axonal survival.

Question 10

What can mutations in the PLP1 gene result in ?

Answer 10

Can cause a spectrum of disorders:

Pelizaeus –Merzbacher the most severe:

• Presents in infancy or early childhood with nystagmus, hypotonia, and cognitive impairment
• Progresses to severe spasticity and ataxia.
• Life span is shortened.

Spastic paraparesis 2 - manifests as spastic paraparesis with or without CNS involvement and usually normal life span.

Question 11

Can malnutrition affect brain growth and development ?

Answer 11

Yes!

• Impact on brain growth and volume
• Impact on myelination
• Lack of energy and deprivation > lack of post natal stimulation and experiences