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Early detection and diagnosis of cerebral palsy
The early identification of infants at risk of cerebral palsy (CP), and their prompt enrolment into appropriate intervention, can help reduce the severity and impact of the associated motor impairment as a child develops. Here, Brian Hoare describes the early signs of CP, the clinical tools that can be used to detect CP in infants as young as three months old, and when to refer to medical and allied health professionals.
WHAT IS CEREBRAL PALSY? Cerebral palsy (CP) is defined as a disorder of movement and posture, causing activity limitation, attributed to non-progressive disturbances related to brain injury early in development (Rosenbaum et al, 2007). It is considered one of the most common causes of childhood physical disability (Oskoui et al, 2013). The motor disorders are often accompanied by disturbances of sensation, cognition, communication, perception and behaviour, and seizures.
Preterm birth is the most important risk factor for CP, although half of children with CP do not have a complicated birth history (Hubermann et al, 2016). Term births are the largest gestational age group, accounting for 59% of all children (Australian Cerebral Palsy Register [ACPR] Group, 2016). In these children, risk factors include placental abnormalities, birth defects, low birthweight, meconium aspiration, instrumental/emergency caesarean delivery, birth asphyxia, neonatal seizures, respiratory distress syndrome, hypoglycaemia and neonatal infection (McIntyre et al, 2013).
The cause of CP is unclear in approximately 80% of cases (Nelson, 2008). In the past, CP was believed to be caused by birth asphyxia; however, this is not the case. In a populationbased study, only 6% of children with CP had a recognised birth complication capable of interrupting oxygen supply (Grether and Nelson, 1997). New evidence suggests that 14% of cases have a genetic component (McMichael et al, 2015; Novak et al, 2017).
In approximately 90% of cases, CP results from damage to healthy brain tissue rather than from abnormalities in brain development (Bax et al, 2006). The stage of brain maturation during which the damage occurs defines the type and site of the brain lesion, as well as the specific response to injury (Graham et al, 2016).
PRESENTATION OF CP CP is a clinical diagnosis based on a combination of clinical and neurological signs (Novak et al, 2017). It covers a wide range of clinical presentations. The distribution of impairment can be described topographically as:
Unilateral – hemiplegia, seen in 38% of cases;
Bilateral – including diplegia, where the lower limbs are affected more than the upper limbs, seen in 37% of cases; and quadriplegia, with all four limbs and trunk affected, seen in 24% of cases (ACPR Group, 2016). BRIAN HOARE Brian Hoare is director of the Cerebral Palsy Group and CPToys, Melbourne, and adjunct associate professor at La Trobe University, Melbourne. Since 2012, he has taught over 1,800 therapists across more than 85 courses that focus on the implementation of evidence-based motorlearning models of therapy in clinical practice. His research interests include cognition and skill acquisition in young children with cerebral palsy.
In addition, four motor types exist that may emerge and change during the first two years of life. These include spasticity, dyskinesia (including dystonia and athetosis), ataxia and mixed (Rosenbaum et al, 2007).
The subjective terms ‘mild’, ‘moderate’ and ‘severe’ are no longer used to describe the severity of CP.
An improving picture
Recent data from the Australian Cerebral Palsy Register, the largest CP register worldwide, indicate that the rate of CP has fallen from one in 400 to one in 700 live births, a 30% reduction (ACPR Group, 2016). The severity of CP has also become milder in the most recently reported birth years. Two out of three children living with CP can walk without assistive equipment and more than half do not have an intellectual disability (ACPR Group, 2016). There are multiple reasons for these reductions in rates and severity, including improvements in education around healthy pregnancies, maternal and neonatal care especially in high-risk pregnancies, neuroprotection, brain repair, early detection and diagnosis, and early therapy intervention.
Classifying functional status A suite of classification tools has been developed to describe a child’s functioning across a range of domains, including the Gross Motor Function Classification System (Palisano et al, 1997), Manual Ability Classification System (Eliasson et al, 2006) and Communication Function Classification System (Hidecker et al, 2011). The introduction of these tools not only provides a common framework and language to describe the functional status of children with CP, but also allows evidence-based prognostication about functional progress in each domain of function, providing parents and clinicians with a means to plan interventions and to judge progress over time (Rosenbaum et al, 2002).
WHY IS EARLY DETECTION AND DIAGNOSIS OF CP IMPORTANT? While the associated brain injury or malformation is non-progressive in children with CP, symptoms, including motor impairment, may worsen over time, leading to varying levels of disability and difficulties with skill development (Hedberg-Graff et al, 2019). As a result, there is a strong shift in current practice away from the ‘wait and see’ approach towards the early detection of infants at risk of CP and facilitating timely access to early intervention (McIntyre et al, 2011). When a diagnosis of CP is suspected but cannot be made with certainty, experts recommend that an interim diagnosis of high risk of CP be given (Novak et al, 2017).
Prompt referral by care providers for early occupational therapy and physiotherapy is critical (Boychuck et al, 2020) as the most rapid gains in gross motor and bimanual abilities for most children with CP have been found to occur in the first two years of development (Rosenbaum et al, 2002; Nordstrand et al, 2016). Maximising this early period of development is important as neurological pathways which remain intact can be harnessed, and enhanced through the mechanism of activity-based or experiencedependent neural plasticity (Friel et al, 2014). Early detection is also important so that parents can receive appropriate psychological and financial support (when available) following diagnosis (Novak et al, 2017). EARLY SIGNS OF CP AND WHEN TO REFER It is critical to acknowledge parental concerns about an infant. Eighty-six per cent of parents of a child with CP suspect it before the diagnosis is made (Baird et al, 2000). In 2020, a group of international experts developed a list of clinical features that should prompt referral for diagnostic assessment of CP (Boychuck et al, 2020). These include:
Early handedness before 12 months of age;
Stiffness or tightness in the legs between six and 12 months of age (e.g., unable to bring toes to mouth);
Persistent fisting of the hands beyond four months of age;
Persistent head-lag beyond four months of age;
Unable to sit without support beyond nine months of age;
Any asymmetry in posture or movement.
Advances in early detection and diagnosis Diagnosis of CP typically occurs between 12 and 24 months of age (Hubermann et al, 2016). However, recent advances in science and clinical assessment provide the opportunity to diagnose CP as early as three months corrected age (a premature baby’s chronological age minus the number of weeks or months it was born before full term), with an accuracy of more than 97%.
A recently published international clinical guideline (Novak et al, 2017) recommends the use of magnetic resonance imaging (MRI), Prechtl’s General Movements Assessment (GMA) and the Hammersmith Infant Neurological Examination (HINE) for early detection of CP (Romeo et al, 2016; Kwong et al, 2018). Each of these assessments has demonstrated high sensitivity and specificity for detecting CP as early as three months corrected age.
The guideline presents two pathways. The first is for infants younger than five months corrected age who have newborn-detectable risks for CP that warrant screening (such as prematurity, atypical intrauterine growth, encephalopathy, genetic abnormalities and seizures) (Novak et al, 2017). This pathway recommends the use of MRI plus the GMA or the HINE.
The second pathway is for infants older than five months corrected age where the pregnancy appeared to be uneventful. Children on this pathway are typically those with unilateral CP. In this group, MRI (where possible) and the HINE are recommended (Novak et al, 2017). More recently the Hand Assessment for Infants (HAI) has been introduced to help accurately predict the risk of unilateral (hemiplegic) CP in infants aged between three and 12 months.
TOOLS FOR THE EARLY DETECTION OF CP
Prechtl’s GMA General movements (GMs) are part of the spontaneous movement repertoire that is present from early fetal stages until the end of the first six months of life (Prechtl, 1990; Kwong et al, 2018). They involve movements of the whole body in a variable sequence of arm, leg, neck and trunk.
The General Movements Trust (general-movements-trust.info) offers training courses in Prechtl’s GMA, which allows clinicians to detect abnormalities in GMs. Two distinct movement patterns can be observed from term age: writhing movements (WMs) and fidgety movements (FMs) (Morgan et al, 2019). WMs are present from term age up to about nine weeks. FMs appear at approximately seven to eight weeks of age and can be present until about 20 weeks (Morgan et al, 2019). Following a brain injury or abnormality, GMs lose their complex and variable character and become monotonous and poor.
During the writhing period abnormal GMs are described as either poor repertoire, cramped-synchronised or chaotic (Morgan et al, 2019). Abnormal GMs at the fidgety age are classified as:
Absent FMs, when normal FMs are never observed;
Abnormal FMs, when FMs can be detected but their amplitude, speed and jerkiness are moderately or greatly exaggerated.
Cramped-synchronized GMs in the writhing period and an absence of fidgety GMs in the fidgety period are predictive of CP with high sensitivity and specificity (Einspieler et al, 2012; Bosanquet et al, 2013). Outcomes from the GMA can also indicate the topography of CP in infants (Novak et al, 2017).
HINE The HINE is a clinical tool designed for evaluating infants between two months and 24 months of age (Romeo et al, 2016). It includes 26 items and can be completed in five to 10 minutes. The global score can range from a minimum of 0 to a maximum of 78. Global scores are reported as optimal if they are 73 or more at nine to 12 months of age, or at least 70 and 67 at six months and three
months of age, respectively. A score of 57 is recommended by the international guideline as the cutoff for predicting CP at the age of three months (Romeo et al, 2013; Novak et al, 2017). HINE scores can also indicate the topography of CP in infants (Novak et al, 2017).
HAI The recently developed HAI quantifies asymmetric hand function by measuring each hand separately as well as both hands together in infants from three to 12 months of age (Krumlinde-Sundholm et al, 2017). For infants presenting with upper limb asymmetry, the HAI can be used to help accurately predict the risk of unilateral CP as early as three months of age (Ryll et al, 2019).
EARLY DIAGNOSIS, IMPROVED OUTCOMES There have been significant recent advances in the ability to accurately detect and diagnose infants with CP. Improved understanding of the mechanisms for activity-based or experience-dependent neural plasticity provides strong support for moving away from a ‘wait and see’ approach and warrants immediate referral to suitably qualified paediatric occupational therapists and physiotherapists to commence a range of evidence-based models of therapy as early as possible (Morgan et al, 2021). Any medical needs of the child should also be managed by a medical specialist.
References
Australian Cerebral Palsy Register Group (2016) Report of the Australian Cerebral Palsy Register, Birth Years 1993–2009. www.cpregister.com/pubs/pdf/ACPRReport_Web_2016.pdf, last accessed 23 April 2022 Baird, G., McConachie, H., Scrutton, D. (2000) Parents’ perceptions of disclosure of the diagnosis of cerebral palsy. Archives of Disease in Childhood 83(6), 475–480. DOI: 10.1136/adc.83.6.475
Bax, M., Tydeman, C., Flodmark, O. (2006) Clinical and MRI correlates of cerebral palsy: the European Cerebral Palsy Study. JAMA 296(13), 1602–1608. DOI: 10.1001/jama.296.13.1602 Bosanquet, M., Copeland, L., Ware, R., Boyd, R. (2013) A systematic review of tests to predict cerebral palsy in young children. Developmental Medicine & Child Neurology 55(5), 418–426. DOI: 10.1111/dmcn.12140 Boychuck, Z., Andersen, J., Bussieres, A., Fehlings, D., Kirton, A., Li, P., OskouI, M., et al (2020) International expert recommendations of clinical features to prompt referral for diagnostic assessment of cerebral palsy. Developmental Medicine & Child Neurology 62(1), 89–96. DOI: 10.1111/dmcn.14252
Einspieler, C., Marschik, P.B., Bos, A.F., Ferrari, F., Cioni, G., Prechtl, H.F. (2012) Early markers for cerebral palsy: insights from the assessment of general movements. Future Neurology 7(6), 709–717. DOI: 10.2217/fnl.12.60
Eliasson, A.C., Krumlinde-Sundholm, L., Rösblad, B., Beckung, E., Arner, M., Ohrvall, A.M., Rosenbaum, P. (2006) The Manual Ability Classification System (MACS) for children with cerebral palsy: scale development and evidence of validity and reliability. Developmental Medicine & Child Neurology 48(7), 549–554. DOI: 10.1017/S0012162206001162
Friel, K.M., Williams, P.T.J.A., Serradj, N., Chakrabarty, S., Martin, J.H. (2014) Activity-based therapies for repair of the corticospinal system injured during development. Frontiers in Neurology 5, 229. DOI: 10.3389/fneur.2014.00229
Graham, H.K., Rosenbaum, P., Paneth, N., Dan, B., Lin, J.P., Damiano, D.L., Becher, J.G., et al (2016) Cerebral palsy. Nature Review Disease Primers 2, 1–24. DOI: 10.1038/nrdp.2015.82 Grether, J.K., Nelson, K.B. (1997) Maternal infection and cerebral palsy in infants of normal birth weight. Journal of the American Medical Association 278(3), 207–211. doi:10.1001/jama.1997.03550030047032 Hedberg-Graff, J., Granström, F., Arner, M., Krumlinde-Sundholm, L. (2019) Upper-limb contracture development in children with cerebral palsy: a population-based study. Developmental Medicine & Child Neurology 61(2), 204–211. DOI: 10.1111/dmcn.14006
Hidecker, M.J.C., Paneth, N., Rosenbaum, P.L., Kent, R.D., Lillie, J., Eulenberg, J.B., Chester Jr, K., et al (2011) Developing and validating the Communication Function Classification System for individuals with cerebral palsy. Developmental Medicine & Child Neurology 53(8), 704–710. DOI: 10.1111/j.14698749.2011.03996.x
Hubermann, L., Boychuck, Z., Shevell, M., Majnemer, A. (2016) Age at referral of children for initial diagnosis of cerebral palsy and rehabilitation: current practices. Journal of Child Neurology 31(3), 364–369. DOI: 10.1177/0883073815596610
Krumlinde-Sundholm, L., Ek, L., Sicola, E., Sjöstrand, L., Guzzetta, A., Sgandurra, G., Cioni, G., Eliasson, A-C. (2017) Development of the Hand Assessment for Infants: evidence of internal scale validity. Developmental Medicine & Child Neurology 59(12), 1276–1283. DOI: 10.1111/dmcn.13585
Kwong, A.K.L., Fitzgerald, T.L., Doyle, L.W., Cheong, J.L.Y., Spittle, A.J. (2018) Predictive validity of spontaneous early infant movement for later cerebral palsy: a systematic review. Developmental Medicine & Child Neurology 60(5), 480–489. DOI: 10.1111/ dmcn.13697
McIntyre, S., Morgan, C., Walker, K., Novak, I. (2011) Cerebral palsy—don’t delay. Developmental Disabilities Research Reviews 17(2), 114–129. DOI: 10.1002/ ddrr.1106
McIntyre, S., Taitz, D., Keogh, J., Goldsmith, S., BadawI, N., Blair, E. (2013) A systematic review of risk factors for cerebral palsy in children born at term in developed countries. Developmental Medicine & Child Neurology 55(6), 499–508. DOI: 10.1111/dmcn.12017 McMichael, G., Bainbridge, M.N., Haan, E., Corbett, M., Gardner, A., Thompson, S., Van Bon, B.W., et al (2015) Whole-exome sequencing points to considerable genetic heterogeneity of cerebral palsy. Molecular Psychiatry 20(2), 176–182. DOI: 10.1038/mp.2014.189 Morgan, C., Fetters, L., Adde, L., Badawi, N., Bancale, A., Boyd, R.N., Chorna, O., et al (2021) Early intervention for children aged 0 to 2 years with or at high risk of cerebral palsy. JAMA Pediatrics 175(8), 846–858. DOI: 10.1001/ jamapediatrics.2021.0878 Morgan, C., Romeo, D.M., Chorna, O., Novak, I., Galea, C., Del Secco, S., Guzzetta, A. (2019) The pooled diagnostic accuracy of neuroimaging, general movements, and neurological examination for diagnosing cerebral palsy early in high-risk infants: a case control study. Journal of Clinical Medicine 8(11), 1879. DOI: 10.3390/jcm8111879 Nelson, K.B. (2008) Causative factors in cerebral palsy. Clinical Obstetrics and Gynecology 51(4), 749–762. DOI: 10.1097/GRF.0b013e318187087c
Nordstrand, L., Eliasson, A.C., Holmefur, M. (2016) Longitudinal development of hand function in children with unilateral spastic cerebral palsy aged 18 months to 12 years. Developmental Medicine & Child Neurology 58(10), 1042–1048. DOI: 10.1111/ dmcn.13106
Novak, I., Morgan, C., Adde, L., Blackman, J., Boyd, R.N., Brunstrom-Hernandez, J., Cioni, G., et al (2017) Early, accurate diagnosis and early intervention in cerebral palsy: advances in diagnosis and treatment. JAMA Pediatrics 171(9), 897–907. DOI: 10.1001/ jamapediatrics.2017.1689 Oskoui, M., Coutinho, F., Dykeman, J., Jetté, N., Pringsheim, T. (2013) An update on the prevalence of cerebral palsy: a systematic review and meta-analysis. Developmental Medicine & Child Neurology 55(6), 509–519. DOI: 10.1111/dmcn.12080
Palisano, R., Rosenbaum, P., Walter, S., Russell, D.J. (1997) Gross Motor Function Classification System for cerebral palsy. Developmental Medicine & Child Neurology 39(4), 214–223. DOI: 10.1111/j.14698749.1997.tb07414.x
Prechtl, H.F.R. (1990) Qualitative changes of spontaneous movements in fetus and preterm infant are a marker of neurological dysfunction. Early Human Development 23(3), 151–158. DOI: 10.1016/03783782(90)90011-7
Romeo, D.M., Ricci, D., Brogna, C., Mercuri, E. (2016) Use of the Hammersmith Infant Neurological Examination in infants with cerebral palsy: a critical review of the literature. Developmental Medicine & Child Neurology 58(3), 240–245. DOI: 10.1111/ dmcn.12876
Romeo, D.M.M., Cioni, M., Palermo, F., Cilauro, S., Romeo, M.G. (2013) Neurological assessment in infants discharged from a neonatal intensive care unit. European Journal of Paediatric Neurology 17(2), 192–198. DOI: 10.1016/j.ejpn.2012.09.006 Rosenbaum, P., Paneth, N., Leviton, A., Goldstein, M., Bax, M., Damiano, D., Dan, B., Jacobsson, B. (2007) A report: the definition and classification of cerebral palsy April 2006. Developmental Medicine & Child Neurology Supplement 109, 8–14 Rosenbaum, P.L., Walter, S.D., Hanna, S.E., Palisano, R.J., Russell, D.J., Raina, P., Wood, E., et al (2002) Prognosis for gross motor function in cerebral palsy: creation of motor development curves. JAMA 288(11), 1357–1363. DOI: 10.1001/jama.288.11.1357 Ryll, U.C., Wagenaar, N., Verhage, C.H., Blennow, M., De Vries, L.S., Eliasson, A-C. (2019) Early prediction of unilateral cerebral palsy in infants with asymmetric perinatal brain injury – model development and internal validation. European Journal of Paediatric Neurology 23(4), 621–628. DOI: 10.1016/j. ejpn.2019.04.004
