Lecture 1 - Normal Development Flashcards
What ages does a Paediatric neuropsychology deal with?
birth-18years. In practice, from 3or4 till 16.
How does brain damage affect children that differs from the way it affects adults?
Brain damage in children DISRUPTS normal development - as it disrupts foundational skills and brain areas essential for further development.
THEREFORE:
* difficulties may manifest during later stages of brain or cognitive development - when foundational skills or brain areas come into play
- AND, the impact of brain impairment is thus typically more generalised
In what three ways can brain damage disrupt normal development in children?
(i.e., it may ___ development, or make it ____, or lead to _____)
- it may delay development (set it back by X time)
- it may make development abnormal (i.e., fundamentally different)
- it may lead to the loss of previously acquired skills
In what way is the paediatric neuropsychology model SIMILAR to adult neuropsychology model?
It uses many of the same foundations as adult neuropsychology model
e. g.,
* localisation of function
- similar causes of brain impairment
- similar range of functional impairment
- ‘dose-response’ relationship remains (i.e., more damage –> worse outcomes)
- Intervention/rehabilitation is still very important
KEY QUESTION: why might a young child with an ABI at a young age only have 5% (difference) in impairment from their peers — but then have this difference increases with age? (i.e., small gap at a young age –> large gap later in development?)
The immediate effects on the child’s brain functioning may be relatively mild, but nevertheless affect fundamental abilities and may damage previously learnt skills.
This leads to cascading effects such as failure to active experience dependant or expectant cognitive functions –> resulting in either delayed or abnormal development trajectories; and more generalised impairment than what you would see in adults.
Prenatal CNS development is mainly concerned with (1)________;
Whilst, postnatal CNS development is mainly concerned with (2)_______>
(1) structural formation, aka the basic ‘hardware’ of the CNS
(2) elaboration of the CNS or establishing connectivity
When does the fastest rate of CNS growth occur?
Prenatally
Describe the prenatal order of structural CNS development: 1. Conception 2. week 2 3. week 3 4, week 4 5. week 5
- Rapid cell-division
- formation of embryonic disc
- Neural plate forms (neuralation)
- Neural tube forms
- cell proliferation of neural tube
What are the three layers of the embryonic disc and what do they become?
- endoderm (bottom layer, becomes internal organs like the respiratory and digestive systems.
- mesoderm (middle layer, becomes skelatal and muscular structure.
- Extoderm (outer layer, skin surface and CNS)
What is neurulation?
The formation of the neural plate in week 3/4 of prenatal development.
[AKA: The folding process in vertebrate embryos, which includes the transformation of the neural plate into the neural tube.]
What is the process whereby the neural plate/neural tube forms?
Neurulation
What are the 3 dimensions along which the neural tube develops?
- Length
- Circumference
- Radial differentiation
How does each of the 3 dimensions of the neural tube relate to features of the CNS?
- Length - Major structural aspects: the forebrain, midbrain, & spinal cord
- Circumference - differentiation between sensory and motor sysmptoms (i.e., the dorsal and ventral stream)
- Radial differentiation - different layers and cell types observed in the braion
Describe the order in which the structural components of the CNS develop?
cerebellar/brainstem –> posterior regions –> anterior regions –> frontal cortex
During week 5 of gestation the neural tube, what three primary vesicles does the neural tube divide into during cell proliferation?
- Prosencephalon
- Mesencephalon
- Rhombencephalon
What are the 3 primary vesicles the neural tube proliferates into. and what are the 5 sub-divisions.
+ what areas of the brain do these divisions become?
- Prosencephalon
a. Telencephalon (forebrain/ i.e., cerebral cortex/cerebrum)
b. Diencephalon (thalamus, hypothalamus, optic vesicles) - Mesencephalon (mid-brain)
- Rhombencephalon
a. Metencephalon (pons and cerebellum)
b. Myelencephalon (medulla oblongata - Spinal cord (the remainder)
What are the openings of the neural tube called? Where are they? When do they close?
Neuropores.
For a short time the neural tube is open both cranially (Top) and caudally (bottom). These openings, called neuropores, close during the 4th week in humans. Improper closure of the neuropores can result in neural tube defects such as anencephaly or spina bifida.
List some possible malformations of the neural tube.
- Anencephaly (malformation at the top end of the neural tube)
- Holoprocenphaly
- Carniosynostosis
- Encephalocelese
- Spina bifida (malformation at the bottom end of the neural tube)
- Arnold-Chiari Malformation
The dorsal part of the neural tube contains the (1) ______ plate ; which is associated primarily with (2)_____.
- Alar
2. Sensation
The ventral part of the neural tube contains the (1) ______ plate ; which is associated primarily with (2)_____.
- Basal
2. Motor control (i.e., muscle control)
What are the four MAIN important processes in prenatal brain CELL development?
- Proliferation - rapid cell divisions and generation of neurons and glial cells
- Migration - cells move to their permanent location
- Differentiation - neurons differentiate into distinct cell types (4 substages)
- Myelination - axons are surrounded by a myelin sheath
