Early Brain development

Development of the Brain’s Wiring Neurogenesis: Manufacturing of brain cells. Migration: Moving cells to their pre-determined place on the cortex. Neuronal differentiation and pathfinding: Growing axons and dendrites to link with other neurons. Synaptogenesis: Developing synapses with other cells. Maturation and pruning: Refining synapses. Gliagenesis (Myelination): Forming of supportive tissue that surrounds neurons and promotes communication between cells. Neurons to Neighborhoods, 2000

Fetal Brain Development Neurogenesis & Neurulation Migration Neuronal Differentiation and Pathfinding Synaptogenesis Maturation and Pruning Glialgenesis/ Mylenination Drawing by Tom Prentiss, Cowan MW 1979. The development of the brain. Scientific American 113; 113-133 3

Migration Forms elevations (gyri) and depressions (sulci) 2 hemispheres bridge 6 layers of cerebral cortex divide into frontal, parietal, temporal and occipital lobes

Synapse Formation Begins about 8 weeks gestation and continues as neurons proliferate, differentiate, and migrate Both axons and dendrites grow and “branch” making connections for transmission of information This is a prerequisite for interaction to occur in the CNS

Migration Forms elevations (gyri) and depressions (sulci) 2 hemispheres bridge 6 layers of cerebral cortex divide into frontal, parietal, temporal and occipital lobes

Synapse Formation Begins about 8 weeks gestation and continues as neurons proliferate, differentiate, and migrate Both axons and dendrites grow and “branch” making connections for transmission of information This is a prerequisite for interaction to occur in the CNS

Synaptogenesis Rapid overproduction of synapses Synapse elimination Experience dependent Synapses are eliminated if they are not used and therefore the frequently used connection are the ones to survive. The effect of experience (normal or abnormal) on this process is increasingly irreversible over time. Volpe,JJ: Neurology of the Newborn, 4th ed. Phiildelphia: WB Saunders, 2001

Neuronal differentiation and pathfinding Experience dependent Effected by myelination The stability and strength of synapses is largely determined by the firing of these connections. The speed of the conduction of the impulses is determined by the development of myelin. The rate and amount of myelination is also effected by experience Volpe,JJ: Neurology of the Newborn, 4th ed. Phiildelphia: WB Saunders, 2001

Myelination Begins at 6 months gestation & continues into adulthood Glial cells produce myelin Fatty covering coats & insulates axons Speeds conduction of impulses Allows more complex functioning True maturity of CNS only occurs after myelineation process has fully developed Volpe,JJ: Neurology of the Newborn, 4th ed. Phiildelphia: WB Saunders, 2001

Plasticity The capactiy to adapt in very specific ways to the changing demands Reorganization of the brains structure and/or function Plasticity refers to the brains capacty to reorganize the structure and/or function in response to specific events Often occurs as a result of a change in the environment Volpe, 2001

“In full term infants, axonal and dendritic proliferation … and cell growth and differentiation … occurs in an environment of mother mediated protection from environmental perturbations, with a steady supply of nutrients, temperature control, and the presence of multiple hormonal regulating systems …” Als, 1997 12

STRATEGIES FOR INDIVIDUALIZED DEVELOPMENTAL CARE

Key Components of Developmentally Supportive Care •Positioning •Feeding support •Kangaroo care •Pain management •Environmental considerations •Parent support •Consistency in caregiving •Structuring caregiving •Pacing of caregiving •Support during transitions in care The once-routinely hourly tasks such as pain assessment and ventilator checks are now carried out while observing and responding to the infant’s behavior.

Why are caregiving approaches so critical? The newborn responds to changes in the environment and to caregiving interventions with: Behavioral changes Physiological changes

NURSERY ENVIRONMENT weather stripping on cabinets and doors, • increase space for each bedside area, weather stripping on cabinets and doors, sound absorbent materials on all surfaces that are appropriate, rubber trash cans carpet incubator covers single patient rooms. Suggestions for environmental changes to decrease the noise level in the NICU environment include increase space for each bedside area, weather stripping on cabinets and doors, sound absorbent materials on all surfaces that are appropriate, rubber trash cans, carpet, incubator covers, single patient rooms.

Collaboration of Care Providers Primary team- includes the family, nursing, medicine, respiratory therapy, social work, OT/SP Developmental specialist support primary teams in developmental care planning and implementation; provide resources

DIRECT INTERVENTION BODY POSITIONING Infants born prematurely will have an immature musculoskeletal system that can be influenced by their positioning In utero---- the uterine walls provide ongoing containment, facilitate trunk and extremity flexion and tucking and provide reactionary forces in response to fetal movements (#55) Preterm infants-----deal with effects of gravity, lack of fluidto support movement and no reactionary forces to support bone and joint formation *** exposture to prolonged atypical postioning in the nicu has been associated with torticollis, positioinal plagiocephaly, reduced ;movement quality and lower extremity malalignment (59,61-63) ***** Developmentally supportive positioing on the other hand, may allow development of normal skeletal alignment and provide opportunities leading to normal movement patterns #59

Positioning for Optimal development of the Neonate Improves alertness and assists with organization Improves alignment of hips and shoulders Comfort Promotes normal development Minimizes abnormal movement patterns Encourage balance between flex/ext Promote symmetry

Developmental Abnormalities caused by poor positioning Elevated and retracted scapula “W” position “Frog” position Hyperextension Show each of these positions and discuss the consequences in the long run. All of these positions do not allow the infant the ability to be in a tucked and rounded position, therefore making it extremely difficulty to self-regulate and obtain deep sleep and comfort. If these positions persist, these will be the synapses and connections that are re-enforced, and will effect later development and motor skills

PRONE Helps develop flexion pattern (Connaly, Montgomery 1987) Facilitates development of early head control (Bobath 1972) Improves oxygenation (Martin et al 1979)

PRONE Hips and knees flexed with knees under hips Arms flexed with hands near head Hand to mouth Head turned to one side Boundaries at sides and feet with foot support to allow neutral position of ankle If not positioned correctly, infants may develop “flat” trunks with hyperextended and excessively rotated cervical spines, as well as abducted hips (horizontal roll upnder the pelvis)