Classification of events contributing to postneonatal cerebral palsy: Development, reliability, and recommendations for use.

AIM: This paper introduces the Surveillance of Cerebral Palsy in Europe (SCPE) classification of events contributing to postneonatally acquired cerebral palsy, presents its interrater reliability, and describes the cases identified in the SCPE database. METHOD: The development of the classification, based on literature review and expert discussions, resulted in six main categories and 19 subcategories. The first chronological event designated as the primary event was mainly reported. Interrater reliability was assessed through online exercise providing 24 clinical vignettes representing single/complex pathways. Percent agreement and Gwet's AC1 index of reliability were estimated. Primary events were described using data of 221 children born between 2008 and 2012. RESULTS: Thirty-nine professionals (21 registries) participated in the reliability exercise. Substantial overall agreement was reached (0.75), with some contrast between complex (0.48, moderate agreement) and single events involved (0.89, almost perfect). The distribution of primary events showed that 32.1% were infections (category A), 23.1% head injuries (B), 15.4% related to surgery or medical interventions (C), 13.1% cerebrovascular accidents (D), 9.1% hypoxic brain damaging events of other origins (E), and 7.2% miscellaneous (F). INTERPRETATION: This classification allows all the events involved to be recorded while consistently reporting the primary event, and may be used in different settings. WHAT THIS PAPER ADDS: A standardized classification enables the description of the events contributing to postneonatal cerebral palsy (CP). The first chronological event in complex pathway leading to CP is coded. Category choice and coding of the primary event identify preventable situations. The detailed 2-level classification is easy to use in various settings. Substantial overall interrater reliability shows that main categories can be consistently differentiated.

Working Memory Training in Norwegian Children with Cerebral Palsy (CP) Show Minimal Evidence of Near and No Far Transfer Effects.

In children with cerebral palsy (CP), learning disabilities are well documented, and impairments in executive functions, such as attention, inhibition, shifting and working memory, represent significant burdens on patients, their families and the society. The aim of this study was to evaluate whether Cogmed RM working memory training could improve working memory in children with CP and investigate whether increased working memory capacity would generalize to other cognitive functions. Twenty-eight children completed the training and the results were compared to a waitlist control group (n = 32). The results yielded three main findings. First, children with CP improved with practice on trained working memory tasks. Second, the intervention group showed minimal near transfer effects to non-trained working memory tasks. Third, no effects on cognitive and behavioral far transfer measures were found.

Association between gestational levels of toxic metals and essential elements and cerebral palsy in children.

Introduction: Cerebral palsy (CP) is the most common motor disability in childhood, but its causes are only partly known. Early-life exposure to toxic metals and inadequate or excess amounts of essential elements can adversely affect brain and nervous system development. However, little is still known about these as perinatal risk factors for CP. This study aims to investigate the associations between second trimester maternal blood levels of toxic metals, essential elements, and mixtures thereof, with CP diagnoses in children. Methods: In a large, population-based prospective birth cohort (The Norwegian Mother, Father, and Child Cohort Study), children with CP diagnoses were identified through The Norwegian Patient Registry and Cerebral Palsy Registry of Norway. One hundred forty-four children with CP and 1,082 controls were included. The relationship between maternal blood concentrations of five toxic metals and six essential elements and CP diagnoses were investigated using mixture approaches: elastic net with stability selection to identify important metals/elements in the mixture in relation to CP; then logistic regressions of the selected metals/elements to estimate odds ratio (OR) of CP and two-way interactions among metals/elements and with child sex and maternal education. Finally, the joint effects of the mixtures on CP diagnoses were estimated using quantile-based g-computation analyses. Results: The essential elements manganese and copper, as well as the toxic metal Hg, were the most important in relation to CP. Elevated maternal levels of copper (OR = 1.40) and manganese (OR = 1.20) were associated with increased risk of CP, while Hg levels were, counterintuitively, inversely related to CP. Metal/element interactions that were associated with CP were observed, and that sex and maternal education influenced the relationships between metals/elements and CP. In the joint mixture approach no significant association between the mixture of metals/elements and CP (OR = 1.00, 95% CI = [0.67, 1.50]) was identified. Conclusion: Using mixture approaches, elevated levels of copper and manganese measured in maternal blood during the second trimester could be related to increased risk of CP in children. The inverse associations between maternal Hg and CP could reflect Hg as a marker of maternal fish intake and thus nutrients beneficial for foetal brain development.

Cerebral palsy in children born after assisted reproductive technology in Norway: Risk, prevalence, and clinical characteristics.

INTRODUCTION: The aim was to investigate the risk, prevalence, and clinical characteristics of cerebral palsy among children born after assisted reproductive technology (ART) in Norway. MATERIAL AND METHODS: All liveborn children from 2002 to 2015 were included. Information was collected from the Medical Birth Registry of Norway, linked to the Norwegian Quality and Surveillance Registry for Cerebral Palsy as of December 31, 2022. Logistic regression analyses were used to calculate the prevalence of cerebral palsy per 1000 live births after ART and natural conception with birth year as covariate, crude odds ratios (OR) for cerebral palsy among children born after ART using children born after natural conception as reference, and OR adjusted for potential confounders, with 95% confidence intervals (CI). Potential mediators of the association were studied in stratified analyses. Descriptive statistics were used to compare proportions in clinical characteristics among children with cerebral palsy born after ART and natural conception. RESULTS: Among 833 645 livebirths, 23 645 children were born after ART and of the latter 97 were diagnosed with cerebral palsy. The overall prevalence of cerebral palsy after ART was 4.10 per 1000 live births (95% CI 3.36-5.00), decreasing from 7.79 per 1000 in 2002 to 3.55 in 2015. Compared with children born after natural conception, the OR for cerebral palsy was 2.01 (95% CI 1.63-2.47) adjusted for mother's age at birth, parity, and pre-pregnancy health. When restricted to singletons born at term, the adjusted OR for cerebral palsy was 1.13 (95% CI 0.76-1.69). The distribution of cerebral palsy subtypes and the severity of gross and fine motor function and associated impairments did not differ significantly between children with cerebral palsy born after ART and natural conception. CONCLUSIONS: Children born after ART had a risk of cerebral palsy that was twice that of children born after natural conception. The increased risk of cerebral palsy after ART is likely attributed to multiple pregnancies and preterm births. The prevalence of cerebral palsy after ART decreased significantly during the study period, despite an increased use of ART in the population. The distribution of clinical characteristics did not differ between children with cerebral palsy born after ART and those born after a natural conception, suggesting that the risk factors for, and causes of cerebral palsy were similar.

Prevalence, birth, and clinical characteristics of dyskinetic cerebral palsy compared with spastic cerebral palsy subtypes: A Norwegian register-based study.

AIM: To study the prevalence, birth, and clinical characteristics of children with dyskinetic cerebral palsy (CP) in Norway compared with spastic quadriplegic CP and other spastic CP subtypes. METHOD: Data on children born from 1996 to 2015 were collected from the Norwegian Quality and Surveillance Registry for Cerebral Palsy and the Medical Birth Registry of Norway. RESULTS: One hundred and seventy (6.8%) children had dyskinetic CP. The birth prevalence decreased during 1996 to 2015 from 0.21 to 0.07 per 1000 livebirths (p < 0.001). Dyskinetic CP was more often associated with term/post-term birth, and motor and associated impairments were more severe compared with spastic bilateral and unilateral CP, but less severe than spastic quadriplegic CP. On neuroimaging, grey matter injuries were most prevalent in dyskinetic CP (mainly basal ganglia/thalamus) and spastic quadriplegic CP (mainly cortico-subcortical), white matter injuries in spastic bilateral, and white and grey matter injuries were equally common in spastic unilateral CP. Normal neuroimaging and brain maldevelopment were present in 25% of children with dyskinetic CP. INTERPRETATION: The decrease in birth prevalence of dyskinetic CP was probably due to improved antenatal and perinatal care. Potential sentinel events at term were more common in dyskinetic CP than other spastic CP subtypes. However, probable antenatal aetiologies were most prevalent. Motor and associated impairments were less severe in children with dyskinetic CP compared with spastic quadriplegic CP. WHAT THIS PAPER ADDS: Birth prevalence of those with dyskinetic and spastic bilateral cerebral palsy (CP) in Norway decreased between 1996 and 2015. Potential sentinel events at term were more common in dyskinetic CP. Nonetheless, probable antenatal aetiologies were most prevalent in dyskinetic CP. Basal ganglia/thalamus lesions were more common in dyskinetic than spastic quadriplegic CP. Motor and associated impairments were milder in dyskinetic than spastic quadriplegic CP.

Norwegian paediatric habilitation centres judge their own competence on cerebral visual impairment as limited.

AIM: Cerebral visual impairment (CVI), a frequently occurring functional impairment in children with neurodevelopmental disorders, leads to communicative, social and academic challenges. In Norway, children with neurodevelopmental disorders are assessed at paediatric habilitation centres. Our aims were to explore how CVI is identified, how paediatric habilitation centres assess their CVI competence and the reported prevalence of CVI among children with cerebral palsy. METHODS: An electronic questionnaire was sent to all 19 Norwegian paediatric habilitation centre leaders in January 2022. The results were analysed quantitatively and qualitatively. The prevalence of CVI among children with cerebral palsy was estimated using register-based data. RESULTS: The questionnaire was answered by 17. Only three judged their habilitation centre as having sufficient competence on CVI. None of the centres used screening questionnaires systematically, and 11 reported that CVI assessment was not good enough. Awareness that a child may have CVI typically occurred during examinations for other diagnoses. The prevalence of CVI among children with cerebral palsy was only 8%, while CVI status was unknown in 33%. CONCLUSION: Better knowledge and assessment of CVI at Norwegian paediatric habilitation centres are needed. CVI appears to be often overlooked in children with neurodevelopmental disorders.

Household income, fetal size and birth weight: an analysis of eight populations.

BACKGROUND: The age at onset of the association between poverty and poor health is not understood. Our hypothesis was that individuals from highest household income (HI), compared to those with lowest HI, will have increased fetal size in the second and third trimester and birth. METHODS: Second and third trimester fetal ultrasound measurements and birth measurements were obtained from eight cohorts. Results were analysed in cross-sectional two-stage individual patient data (IPD) analyses and also a longitudinal one-stage IPD analysis. RESULTS: The eight cohorts included 21 714 individuals. In the two-stage (cross-sectional) IPD analysis, individuals from the highest HI category compared with those from the lowest HI category had larger head size at birth (mean difference 0.22 z score (0.07, 0.36)), in the third trimester (0.25 (0.16, 0.33)) and second trimester (0.11 (0.02, 0.19)). Weight was higher at birth in the highest HI category. In the one-stage (longitudinal) IPD analysis which included data from six cohorts (n=11 062), head size was larger (mean difference 0.13 (0.03, 0.23)) for individuals in the highest HI compared with lowest category, and this difference became greater between the second trimester and birth. Similarly, in the one-stage IPD, weight was heavier in second highest HI category compared with the lowest (mean difference 0.10 (0 .00, 0.20)) and the difference widened as pregnancy progressed. Length was not linked to HI category in the longitudinal model. CONCLUSIONS: The association between HI, an index of poverty, and fetal size is already present in the second trimester.

High occurrence of perinatal risk factors and more severe impairments in children with postneonatal cerebral palsy in Norway.

AIM: To describe causal events, perinatal risk factors and clinical characteristics in children with postneonatal cerebral palsy (PNCP). METHODS: Population-based registry study of Norwegian children born 1999-2013. Prevalence, causal events and clinical characteristics of PNCP were described. The occurrence of perinatal risk factors for CP was compared with the general population. RESULTS: Among 1710 children with CP, 67 had PNCP (3.9%; 0.75 per 10,000 livebirths [95%CI: 0.59-0.96]). The prevalence of PNCP decreased during the study period. Leading causal events were cerebrovascular events (32.8%), head injuries/other accidents (22.4%), infections (19.4%) and hypoxic events (14.9%). Spastic hemiplegic (53.7%) or spastic quadriplegic/dyskinetic CP (31.3%) was more common in children with PNCP than non-PNCP (42.3% and 20.1%, respectively; p < 0.001). Children with PNCP had more severe motor and associated impairments. Perinatal risk factors for CP were more common in children with PNCP than in the general population. CONCLUSION: The prevalence of PNCP among Norwegian children was low and decreasing. The main causes were cerebrovascular events and head injuries/other accidents. Although spastic hemiplegic CP was the dominating subtype, children with PNCP had more severe motor and associated impairments than children with non-PNCP, as well as a higher occurrence of perinatal risk factors than in the general population.

Interobserver Reliability for Identifying Specific Patterns of Placental Injury as Defined by the Amsterdam Classification.

CONTEXT.­: Placental pathology is an essential tool for understanding neonatal illness. The recent Amsterdam international consensus has standardized criteria and terminology, providing harmonized data for research and clinical care. OBJECTIVE.­: To evaluate the interobserver reliability of these criteria between pathologists at different levels of experience using digitally scanned slides from placentas in a birth population including a large proportion of normal deliveries. DESIGN.­: This was a secondary analysis of selected placentas from a large case-control study of placental lesions associated with neonatal encephalopathy. Histologic slides from 80 placentas were digitally scanned and blindly evaluated by 6 pathologists. Interobserver reliability was assessed by positive and negative agreement, Fleiss κ, and interrater correlation coefficients. RESULTS.­: Overall agreement on the diagnosis, grading, and staging of acute chorioamnionitis and villitis of unknown etiology was moderate to good for all observers and good to excellent for a subset of 4 observers. Agreement on the diagnosis and subtyping of fetal vascular malperfusion was poor to fair for all observers and fair to moderate for the subset of 4 pathologists. Agreement on accelerated villous maturation was poor. CONCLUSIONS.­: This study critically evaluates interobserver reliability for lesions defined by the Amsterdam consensus using scanned images with a low frequency of pathologic lesions. Although reliability was good to excellent for inflammatory lesions, lower reliability for vascular lesions emphasizes the need to more explicitly define the specific histologic features and boundaries for these patterns.

External validity of the Both Hands Assessment for evaluating bimanual performance in children with bilateral cerebral palsy.

AIM: To investigate the external validity of the Both Hands Assessment (BoHA), a new test evaluating bimanual performance in children with bilateral cerebral palsy (CP), by analysing its relationship to established measurements of hand function and self-care skills. METHOD: In this cross-sectional study, we recruited children with bilateral CP and manual ability corresponding to Manual Ability Classification System (MACS) levels I to III attending three habilitation units in Norway. All participants completed the BoHA. Unimanual capacity was assessed using the Bimanual Fine Motor Function (BFMF) classification, the Box and Block Test (BBT), and the Melbourne Assessment 2 (MA2). Self-care skills were assessed with the Pediatric Evaluation of Disability Inventory (PEDI). RESULTS: Thirty-nine children (19 males, 20 females; mean age 8y 2mo, SD 2y 8mo; age range 2y 8mo-12y 6mo) were included. Spearman's correlation coefficient (ρ) suggested high correlation between the BoHA and MACS (p=0.89; 95% confidence interval [CI] 0.79-0.94), BFMF classification (p=0.84; 95% CI 0.71-0.91), and BBT for the non-dominant (p=0.85; 95% CI 0.68-0.95) and dominant hand (p=0.72; 95% CI 0.53-0.85). The Spearman's ρ between the BoHA and the MA2 subscales varied between 0.48 and 0.83, while the PEDI's ρ was 0.51 (95% CI 0.33-0.67). INTERPRETATION: The BoHA provides valid measures of hand use as suggested by its high correlation with other activity-based measures of hand function.

Incidence of invasive Group B Streptococcal infection and the risk of infant death and cerebral palsy: a Norwegian Cohort Study.

BACKGROUND: Group B Streptococcus (GBS) is the leading cause of invasive neonatal infection worldwide. In high-income countries mortality rates are 4-10%, and among survivors of GBS meningitis 30-50% have neurodevelopmental impairments. We hypothesized that invasive GBS infection was associated with increased risk of infant mortality and cerebral palsy (CP). METHODS: All children born alive in Norway during 1996-2012 were included. Data were collected from three national registers. Invasive GBS infection during infancy was categorized into early-onset disease (EOD), late-onset disease (LOD), and very late-onset disease (VLOD). Primary outcomes were infant mortality and CP. RESULTS: Invasive GBS infection was diagnosed in 625 children (incidence: 0.62 per 1000 live births; 95% confidence interval (CI): 0.57-0.67). The incidence of EOD was 0.41 (0.37-0.45), of LOD 0.20 (0.17-0.23), and of VLOD 0.012 (0.007-0.021). The annual incidence of LOD increased slightly. Among infected infants, 44 (7%) died (odds ratio (OR): 24.5; 95% CI: 18.0-33.3 compared with the background population). Among survivors, 24 (4.1%) children were later diagnosed with CP, compared with 1887 (0.19%) in the background population (OR: 22.9; 95% CI: 15.1-34.5). CONCLUSION: Despite a relatively low incidence of invasive GBS infection in Norway, the risk of death and CP remains high. Improvements in prevention strategies are needed. IMPACT: During the first decade of the twenty-first century, invasive GBS disease in infancy is still associated with high mortality. Despite the overall low incidence of invasive GBS disease, the incidence of LOD increased during the study period. The finding that invasive GBS infection in the neonatal period or during infancy is associated with an excess risk of CP, comparable to the risk following moderate preterm birth and moderate low Apgar scores, adds to the existing literature. The results of this study emphasize the importance of adhering to guidelines and the need for better prevention strategies.

Does caesarean delivery in the first pregnancy increase the risk for adverse outcome in the second? A registry-based cohort study on first and second singleton births in Norway.

OBJECTIVE: To explore if newborns in the second pregnancy following a previous caesarean delivery (CD) have higher risk of perinatal mortality or cerebral palsy than newborns in pregnancies following a previous vaginal delivery (VD). DESIGN: Cohort study with information from the Medical Birth Registry of Norway and the Cerebral Palsy Registry of Norway. SETTING: Births in Norway. PARTICIPANTS: 294 598 women with their first and second singleton delivery during 1996-2015. MAIN OUTCOME MEASURES: Stillbirth, perinatal mortality, neonatal mortality and cerebral palsy. RESULTS: Among 294 598 included women, 42 962 (15%) had a CD in their first pregnancy while 251 636 (85%) had a VD. Compared with the second delivery of mothers with a previous VD, the adjusted OR (adjOR), for stillbirth in the second pregnancy following a previous CD was 1.45, 95% CI 1.22 to 1.73; for perinatal death the adjOR was 1.42 (1.22 to 1.73) and for neonatal death 1.13 (0.86 to 1.49). Among children who survived the neonatal period, the adjOR for cerebral palsy was 1.27 (0.99 to 1.64). Secondary outcomes, including small for gestational age, preterm and very preterm birth, uterine rupture and placental complications (eg, postpartum haemorrhage and pre-eclampsia) were more frequent in the subsequent pregnancy following a previous CD compared with a previous VD, in particular for uterine rupture adjOR 86.7 (48.2 to 156.1). Adjustment for potential confounders attenuated the ORs somewhat, but the excess risk in the second pregnancy persisted for all outcomes. CONCLUSION: A previous CD was in this study associated with increased risk for stillbirth and perinatal death compared with a previous VD. Although less robust, we also found that a previous CD was associated with a slightly increased risk of cerebral palsy among children surviving the neonatal period. The aetiology behind these associations needs further investigation.

Access to Intrathecal Baclofen Treatment for Children with Cerebral Palsy in European Countries: An SCPE Survey Reveals Important Differences.

AIM: The aim is to study access to intrathecal baclofen (ITB) for children with cerebral palsy (CP) in Europe, as an indicator of access to advanced care. METHODS: Surveys were sent to CP registers, clinical networks, and pump manufacturers. Enquiries were made about ITB treatment in children born in 1990 to 2005 by sex, CP type, level of gross motor function classification system (GMFCS) and age at the start of treatment. Access to ITB was related to the country's gross domestic product (GDP) and % GDP spent on health. RESULTS: In 2011 population-based data from Sweden, Norway, England, Portugal, Slovenia, and Denmark showed that 114 (3.4%) of 3,398 children with CP were treated with ITB, varying from 0.4 to 4.7% between centers. The majority of the children were at GMFCS levels IV-V and had bilateral spastic CP. In Sweden, dyskinetic CP was the most commonly treated subtype. Boys were more often treated with ITB than girls (p = 0.014). ITB was reported to be available for children with CP in 25 of 43 countries. Access to ITB was associated with a higher GDP and %GDP spent on health (p < 0.01). Updated information from 2019 showed remaining differences between countries in ITB treatment and sex difference in treated children was maintained. CONCLUSION: There is a significant difference in access to ITB for children with CP across Europe. More boys than girls are treated. Access to ITB for children with CP is associated with GDP and percent of GDP spent on health in the country.

Prelabor rupture of membranes and the association with cerebral palsy in term born children: a national registry-based cohort study.

BACKGROUND: Guidelines regarding management of prelabor rupture of membranes (PROM) at term vary between immediate induction and expectant management. A long interval between PROM and delivery increases the risk for perinatal infections. Severe perinatal infections are associated with excess risk for cerebral palsy (CP) and perinatal death. We investigated if increasing intervals between PROM and delivery were associated with perinatal death or CP. METHODS: Eligible to participate in this population-based cohort-study were term born singletons without congenital malformations born in Norway during 1999-2009. Data was retrieved from the Medical Birth Registry of Norway (MBRN) and the Cerebral Palsy Register of Norway. In line with the registration in the MBRN, intervals between PROM and delivery of more than 24 h was defined as 'prolonged' and intervals between 12 and 24 h as 'intermediate'. Outcomes were stillbirth, death during delivery, neonatal mortality and CP. Logistic regression was used to calculate odds ratio (OR) with 95% confidence intervals (CI) for adverse outcomes in children born after prolonged and intermediate intervals, compared with a reference group comprising all children born less than 12 h after PROM or without PROM. RESULTS: Among 559,972 births, 34,759 children were born after intermediate and 30,332 were born after prolonged intervals. There was no association between increasing intervals and death during delivery or in the neonatal period, while the prevalence of stillbirths decreased with increasing intervals. Among children born after intermediate intervals 38 (0.11%) had CP, while among those born after prolonged intervals 46 (0.15%) had CP. Compared with the reference group, the OR for CP was 1.16 (CI; 0.83 to 1.61) after intermediate and 1.61 (CI; 1.19 to 2.18) after prolonged intervals. Adjusting for antenatal factors did not affect these associations. Among children with CP the proportion with diffuse cortical injury and basal ganglia pathology on cerebral MRI, consistent with hypoxic-ischemic injuries, increased with increasing intervals. CONCLUSION: Intervals between PROM and delivery of more than 24 h were associated with CP, but not with neonatal mortality or death during delivery. The inverse association with stillbirth is probably due to reverse causality.