Updated: Feb 12
Why is early intervention so significant? Why is it that everywhere you look as a therapist you see the words "early childhood development", "early intervention" and "first 1000 days of life"? Is it really THAT important? And what if I missed the boat?
In order to comprehend why early intervention is so effective, one must first understand how the brain develops. It is important to note that the young brain actually overproduces synapses between neurons, up to twice as many as will eventually make it to adulthood (1). Even though synaptogenesis (the production of synapses) continues until the corrected age of three years and beyond, there is a period of exuberant synaptogenesis during the first year of life (2). This overabundance of synapses allows for high variability during early development, as the most active synapses will be retained, while unused synapses will be eliminated through synaptic pruning.
Synapses which are used and strengthened during the synaptogenesis phase have a better chance of being retained during the pruning phase, and synapses which are not used may be eliminated. This is specifically relevant for children with cerebral palsy. They often do not develop basic abilities without external input, and if the synapses for these basic abilities are not established, they may be pruned. This is not to say that it is impossible for children with CP to learn new skills at a later age, but it definitely becomes more difficult, and more intense stimulation is needed for new learning to occur (3). Secondary complications such as contractures and deformities also impede the effectiveness of later intervention. This strengthens the case for early intervention during the first two years of life, prior to the increase in synaptic pruning at about corrected age 24 months.
Parallel to the above processes, the neurons in the central nervous system are being myelinated. Myelin is a lipid substance that forms a sheath around the axons of certain neurons through a process called myelination. Myelinated axons have the ability to conduct impulses hundreds of times faster than unmyelinated axons, and as such myelination has an important effect on the formation of neural pathways.
It has been found that electrical impulse activity within a neuron can affect myelination and that practising certain activities (playing the piano in the specific study) resulted in an increase in myelination in specific brain areas when compared to a control group (4). This implies that axons that are fired more frequently might stand a better chance at myelination.
Myelination commences during the second trimester of gestation, specifically around 16 weeks gestational age (5&6) and then continues on into adulthood (7). However, Johnson states that the “most rapid changes (in myelination) occur during the first 2 years” of a child’s life (8 p.476). This serves to further strengthen the case for early intervention during the first two years of life, as it seems that early experiences are important for both synapse retention and myelination of the axons of specific neurons.
Both synaptic pruning and myelination can be seen as underlying processes to neural plasticity in the young brain (4&9) and could be the reasons why specific interventions have a greater impact when applied during this sensitive period than at an older age. Furthermore, this implies that the damaged brain has the potential for change at a neuronal level, especially so in the infant and young child.
So what does this mean for a child with CP? Cerebral palsy is considered to be the leading cause of motor disability in childhood worldwide (10), and yet the process of diagnosing a child can still be long and drawn out - often spanning across the first 18-24 months of the child’s life. Seeing as so many important neural processes are playing out during the first two years of a child’s life, receiving a diagnosis only at two years could severely impact on a child’s potential for optimal development. This is especially relevant in the South African context, where numerous people do not have easy access to specialists, or even basic medical health care, and where the diagnosing of CP oftentimes rely on developmental milestone screenings.
A recent review by Novak et. al (11) recommends specific tools for the accurate early detection of cerebral palsy. In children under 5 months (corrected age), the General Movement Assessment (GMA) is recommended in conjunction with neonatal MRIs. In the event that an MRI is unavailable, the GMA is recommended in conjunction with the Hammersmith Infant Neurological Examination (HINE). However, not all early intervention practitioners are trained in the use of these tools, and many have not even heard of them! How can we provide effective early services if we do not know who to provide them to?
The past few years have yielded many exciting studies on early identification and intervention for children at risk of cerebral palsy, and globally we are seeing a shift in what people perceive as “early intervention” to include the first year of life. However, South Africa is still far behind on this trend, with late diagnoses, lacking human resources for early intervention and no standard care models in place for this vulnerable group of infants.
As clinicians, it is our responsibility to stay on top of the newest evidence and to apply it to our practice. It is our duty to read articles, attend courses and be conscious in our decision making when choosing treatment and assessment methods. Furthermore, we have the task of applying first world research in a third world country, and sometimes we have to be very creative about it!
It is time that South Africa steps up to the plate and really accepts the challenge that is TRUE early intervention. We cannot let the first few months of life pass by with a "wait-and-see" attitude anymore - we know better than that! Our country's babies depend on us, and we cannot let them down. In the words of late former President Nelson Mandela: "It always seems impossible until it's done."
Are you ready to take up the challenge?
Eliot, L. (1999). What’s going on in there: How the brain and mind develop in the first five years of life. New York: Bantam Books.
Huttenlocher, P., R. (1994). Synaptogenesis, synapse elimination, and neural plasticity in human cerebral cortex. In C. A. Nelson (Ed.), Threats to optimal development: Integrating biological, psychological, and social risk factors (pp. 35-54). New Jersey: Lawrence Erlbaum Associates, Inc.
Farran, D. C. (2001). Critical Periods and early intervention. In D. B. Bailey, J. T. Bruer, F. J. Symons,& J. W. Lichtman (Eds.), Critical thinking about critical periods (pp. 233-265). Baltimore: Paul H. Brookes. Pub. Co.
Fields, R. D. (2005). Myelination: An overlooked mechanism of synaptic plasticity? Neuroscientist 11(6), 528-531.
Hadders-Algra, M. (2014). Early diagnosis and early intervention in cerebral palsy. Frontiers in Neurology 5, 9-21. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4173665/pdf/fneur-05-00185.pdf
van der Knaap, M. S., Valk, J. (1995). Magnetic resonance of myelin, myelination, and myelin disorders (2nd ed.). Berlin: Springer-Verlag.
Lenroot, R. K., Giedd, J.N. (2004). Brain development in children and adolescents: Insights from anatomical magnetic resonance imaging. Neuroscience and biobehavioral review 30(2006), 718-729.
Johnson, M. H. (2001). Functional brain development in humans. Nature reviews: Neuroscience 2, 475-483.
Nelson, C. A. (2000). The neurobiological bases of early intervention. In J. P. Shonkoff, & S. J. Meisels (Eds.), Handbook of early childhood intervention (2nd ed., pp. 204-227). Cambridge: Cambridge University Press.
Stavsky M, Mor O, Mastrolia SA, Greenbaum S, Than NG, Erez O. (2017). Cerebral palsy – Trends in epidemiology and recent development in prenatal mechanisms of disease, treatment, and prevention. Frontiers in Pediatrics 5, 21. Retrieved from: 10.3389/fped.2017.00021
Novak I, Morgan C, Adde L, Blackman J, Roslyn N, Brunstrom-Hernandez J et al. (2017). Early, accurate diagnosis and early intervention in cerebral palsy: Advances in diagnosis and treatment. JAMA Pediatrics 171(9), 897-907. Retrieved from: 10.1001/jamapediatrics.2017.1689.