Congenital non-central nervous system malformations in cerebral palsy: a distinct subset?

Evaluation of risk factors for cerebral palsy

Background

Cerebral palsy (CP) has been identified as one of the most important and common causes of childhood disabilities worldwide and is often accompanied by multiple comorbidities. CP is defined as a group of disorders of the development of movement and posture, causing activity limitation that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The objective of our study was to describe main clinical pattern and motor impairments of our patients, and to evaluate the presence of risk factors and if there is a relation to the type of cerebral palsy.

Methods

Children with cerebral palsy were retrospectively enrolled over 2 years from the neurology outpatient clinics. Cerebral palsy risk factors and motor impairments were determined through caregiver interviews, review of medical records, and direct physical examination.

Results

One thousand children with cerebral palsy were enrolled. Subjects were 64.4% male, with a median age of 2.5 years. The risk factors for cerebral palsy in our study were antenatal (21%), natal and post-natal (30.5%), post-neonatal (17.1%), and unidentified (31.4%). Antenatal as CNS malformation (26.6%), maternal DM (17.6%), prolonged rupture of membrane (11.9%), maternal hemorrhage (10.4%), and pre-eclampsia (4.7%). Natal and post-natal as hypoxic ischemic encephalopathy (28.5%), infection (16.3%), hyperbilirubinemia (12.7%), cerebrovascular accidents (8.8%), meconium aspiration (6.2%), and intracranial hemorrhage. Post-neonatal as CNS infection (34.5%), cerebrovascular accidents (28.6%), sepsis (23.9%), and intracranial hemorrhage (8.7%).

Conclusions

Cerebral palsy has different etiologies and risk factors. Further studies are necessary to determine optimal preventative strategies in these patients.

Congenital Malformations in Children With Cerebral Palsy: Is Prematurity Protective?

BACKGROUND

Congenital malformations are more common in children who are born prematurely, and prematurity is the leading risk factor for cerebral palsy. The primary objective of this study was to describe the profile of congenital malformations in a Canadian cohort of children with cerebral palsy. The secondary objectives were to compare the profiles of children with cerebral palsy with and without a congenital malformation and explore the possible role of prematurity.

METHODS

This retrospective cohort study utilized data from the Canadian Cerebral Palsy Registry, a population based registry of children with a confirmed diagnosis of cerebral palsy. Differences between groups were compared using Pearson's chi-square and Student t test as appropriate. Odds ratios and 95% confidence intervals were calculated RESULTS: Congenital malformations were present in 23% participants. In term-born children, brain malformations were the most common, whereas heart and gastrointestinal malformations were more common in children born prematurely. Children with a malformation had higher odds of being born at term (odds ratio 1.57, 95% confidence interval 1.20 to 2.04); having hypotonic, ataxic, or dyskinetic cerebral palsy (odds ratio 1.92, 95% confidence interval 1.35 to 2.72; being nonambulatory (odds ratio 1.70, 95% confidence interval 1.29 to 2.25); and having cerebral palsy-associated comorbidities.

CONCLUSIONS

One in four children with cerebral palsy have an associated congenital malformation. Their profile of term birth, higher Apgar scores, and lower frequency of perinatal seizures suggests a distinct causal pathway.

Congenital anomalies in children with cerebral palsy in rural Bangladesh

AIM

To determine the proportion of children with cerebral palsy (CP) who had major congenital anomalies, describe the types of disorders, and report on the children's functional outcomes.

METHOD

Data were extracted from the Bangladesh Cerebral Palsy Register (BCPR). Descriptive analyses were conducted on children with CP and major congenital anomalies. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to measure the association between major congenital anomalies, clinical severity, and presence of comorbidities.

RESULTS

Between January 2015 and December 2016, 726 children with CP were newly registered with the BCPR (277 females, 449 males; mean age [SD] at registration 90mo [54mo], 4mo-18y). Seventy-eight children (11%) had a major congenital anomaly. Neurological (86%) and musculoskeletal congenital anomalies (10%) were the most common. Microcephaly was the most common congenital anomaly (83%). The odds of severe functional motor limitations (OR=2.4, 95% CI=1.9-2.9), epilepsy (OR=1.6, 95% CI=1.1-2.1), visual impairment (OR=2.6, 95% CI=2.0-3.2), presence of strabismus (OR=3.9, 95% CI=3.8-4.4), hearing (OR=1.2, 95% CI=0.6-1.9), speech (OR=5.4, 95% CI=4.6-6.2), and intellectual impairments (OR=2.3, 95% CI=1.8-2.8) were higher in children with congenital anomalies compared to children without.

INTERPRETATION

The proportion of children with major congenital anomalies in the BCPR (11%) was lower than that identified in higher-income countries. This may be because of differences in how congenital anomalies are diagnosed as well as the impact of survival bias. In Bangladesh, children with CP and major congenital anomalies are more likely to have severe functional motor limitations and associated comorbidities.

WHAT THIS PAPER ADDS

Eleven per cent of children with cerebral palsy (CP) in Bangladesh had major congenital anomalies. Neurological and musculoskeletal congenital anomalies were the most common. Severe functional motor limitations and associated comorbidities were more common in children presenting with CP and major congenital anomalies.

Suckling, Feeding, and Swallowing: Behaviors, Circuits, and Targets for Neurodevelopmental Pathology

All mammals must suckle and swallow at birth, and subsequently chew and swallow solid foods, for optimal growth and health. These initially innate behaviors depend critically upon coordinated development of the mouth, tongue, pharynx, and larynx as well as the cranial nerves that control these structures. Disrupted suckling, feeding, and swallowing from birth onward-perinatal dysphagia-is often associated with several neurodevelopmental disorders that subsequently alter complex behaviors. Apparently, a broad range of neurodevelopmental pathologic mechanisms also target oropharyngeal and cranial nerve differentiation. These aberrant mechanisms, including altered patterning, progenitor specification, and neurite growth, prefigure dysphagia and may then compromise circuits for additional behavioral capacities. Thus, perinatal dysphagia may be an early indicator of disrupted genetic and developmental programs that compromise neural circuits and yield a broad range of behavioral deficits in neurodevelopmental disorders.

Congenital Anomalies in Children With Cerebral Palsy: A Systematic Review

Congenital anomalies are a strong risk factor for cerebral palsy, particularly for children born at term. This systematic review aimed to address gaps in our understanding of the association between congenital anomalies and cerebral palsy. Eight population-based studies (n = 10 081) were identified. Congenital anomalies were reported in 12% to 32% of children with pre/perinatal brain injury and 20% of children with postneonatal brain injury. Variation between studies included study cohort inclusion criteria and the definitions and classification of included anomalies. The most common cerebral anomalies were microcephaly and hydrocephaly, whereas circulatory system anomalies were the most common noncerebral anomalies. The proportion of congenital anomalies was higher in children born at term than preterm. Synthesizing the highest quality data published, this review identified that congenital anomalies are common in cerebral palsy. New collaborative research, addressing sources of variation, is vital to identify pathways to cerebral palsy that include specific congenital anomalies, and explore opportunities for prevention.

Comprehensive investigation of congenital anomalies in cerebral palsy: protocol for a European-Australian population-based data linkage study (The Comprehensive CA-CP Study)

INTRODUCTION

Cerebral palsy (CP), an umbrella term for non-progressive conditions of cerebral origin resulting in motor impairments, is collectively the most common cause of physical disability in childhood. Cerebral and/or non-cerebral congenital anomalies are present in 15%-40% of children with CP. In order to identify effective prevention strategies for this substantial proportion of CP, a comprehensive understanding of the epidemiology of these congenital anomalies is required. International collaboration is needed, as previous attempts have fallen short due to a lack of power, since the anomalies are individually rare and CP comprises many clinical descriptions. The aim of this study is to generate new knowledge about the aetiologies of CP through a focused investigation into the role of congenital anomalies.

METHODS AND ANALYSIS

This collaborative, population-based data linkage study includes nine geographic regions (six in Europe, three in Australia) served by both congenital anomaly and CP registers. Register data for children with CP (both with and without congenital anomalies) and children with specific congenital anomalies (without CP) born between 1991 and 2009 will be linked and de-identified within each region. The resulting linked data sets will be quality assured, recoded, harmonised and then pooled into one data set. Analysis of the combined data set will include: frequencies/proportions of congenital anomalies and outcomes (type of CP, severity, impairments); descriptive analyses comparing timing of congenital anomaly development and brain injury/abnormality responsible for CP; ORs to calculate the odds of CP following a specific congenital anomaly; and identification of anomalies on causal pathways to CP.

ETHICS AND DISSEMINATION

Ethics approval for this collaborative study, The Comprehensive CA-CP Study, has been obtained from the Cerebral Palsy Alliance Human Research Ethics Committee (EC00402). Study findings will be disseminated at conferences and published in peer-reviewed journals, and recommendations will be made regarding the collection and classification of congenital anomaly data by CP registers.

The Association Between Maternal Age and Cerebral Palsy Risk Factors

BACKGROUND

Advanced maternal age is associated with higher frequencies of antenatal and perinatal conditions, as well as a higher risk of cerebral palsy in offspring. We explore the association between maternal age and specific cerebral palsy risk factors.

METHODS

Data were extracted from the Canadian Cerebral Palsy Registry. Maternal age was categorized as ≥35 years of age and less than 20 years of age at the time of birth. Chi-square and multivariate logistic regressions were performed to calculate odds ratios and their 95% confidence intervals.

RESULTS

The final sample consisted of 1391 children with cerebral palsy, with 19% of children having mothers aged 35 or older and 4% of children having mothers below the age of 20. Univariate analyses showed that mothers aged 35 or older were more likely to have gestational diabetes (odds ratio 1.9, 95% confidence interval 1.3 to 2.8), to have a history of miscarriage (odds ratio 1.8, 95% confidence interval 1.3 to 2.4), to have undergone fertility treatments (odds ratio 2.4, 95% confidence interval 1.5 to 3.9), and to have delivered by Caesarean section (odds ratio 1.6, 95% confidence interval 1.2 to 2.2). These findings were supported by multivariate analyses. Children with mothers below the age of 20 were more likely to have a congenital malformation (odds ratio 2.4, 95% confidence interval 1.4 to 4.2), which is also supported by multivariate analysis.

CONCLUSIONS

The risk factor profiles of children with cerebral palsy vary by maternal age. Future studies are warranted to further our understanding of the compound causal pathways leading to cerebral palsy and the observed greater prevalence of cerebral palsy with increasing maternal age.

Cryptorchidism in Boys With Cerebral Palsy Is Associated With the Severity of Disease and With Co-Occurrence of Other Congenital Anomalies

BACKGROUND

Cryptorchidism is reported in 40-50% of small case series of cerebral palsy (CP) and attributed to hypothalamic-pituitary-gonadal axis abnormalities, intellectual disability (ID), or cremaster spasticity. We collected demographic and clinical data to define the frequency of cryptorchidism and clinical comorbidities in a large CP population.

METHODS

Electronic health record data were collected for all male patients ≥7 years of age seen in a large, multidisciplinary CP clinic between 2000 and 2016. Variables including age, testicular position, surgical findings, CP severity, birth history, and comorbidities were tested for association using univariable and stepwise backward logistic regression analyses.

RESULTS

Of 839 established patients, testis position was scrotal in 553, undescended in 185 (24%), retractile in 38 (5%), and undocumented in 63 cases. Cryptorchidism were diagnosed at a mean age of 5.8 years, with 20% documented as acquired, and testes were most commonly in the superficial inguinal pouch (41%) and associated with an inguinal hernia (56%). Severity was bilateral in 114/166 (69%) undescended and 24/36 (66%) retractile cases, respectively. Mean birth weight and the frequency of prematurity (55, 58, and 54%) and multiple birth (14, 13, and 9%) were not significantly different among the three groups. We observed a strong ordinal trend in the frequency of comorbidities, including quadriplegia, syndromic features/known genetic disease, intrauterine growth restriction (IUGR), death, brain malformations, seizures, gastrostomy, absent continence, ID and hearing, speech or visual impairment, with the retractile group holding the intermediate position for the majority. The stepwise multivariable analysis showed independent positive associations of cryptorchidism with quadriplegia, syndromic features/known genetic disease, hearing loss, and absent continence, and inverse associations with gestational age and multiple birth.

CONCLUSION

These data suggest that cryptorchidism is less common than previously reported in CP cases, but most strongly associated with quadriplegia. Delayed diagnosis may be related to an acquired condition or to the multiple additional functional deficits that occur in this population. Our data suggest that UDT and CP may both be components of malformation syndromes occurring in singleton births whose clinical features are more likely to include earlier delivery, IUGR, hearing loss, and/or global spasticity.

Congenital anomalies and the severity of impairments for cerebral palsy

AIM

To study the prevalence of congenital anomalies among children with cerebral palsy (CP) born at term or late preterm, and if CP subtypes and clinical manifestations differ between children with and without congenital anomalies.

METHOD

This was a cross-sectional study using data from the Cerebral Palsy Register of Norway and the Medical Birth Registry of Norway. All children with congenital CP born at and later than 34 weeks' gestation in Norway from 1999 to 2009 were included. Anomalies were classified according to the European Surveillance of Congenital Anomalies classification guidelines. Groups were compared using Fisher's exact test, Kruskal-Wallis test, and the Mann-Whitney U test.

RESULTS

Among 685 children with CP, 169 (25%) had a congenital anomaly; 125 within the central nervous system. Spastic bilateral CP was more prevalent in children with anomalies (42%) than in children without (34%; p=0.011). Children with anomalies less frequently had low Apgar scores (p<0.001), but more often had severe limitations in gross- and fine-motor function, speech impairments, epilepsy, severe vision, and hearing impairments than children without anomalies (p<0.03).

INTERPRETATION

Although children with CP and anomalies had low Apgar scores less frequently, they had more severe limitations in motor function and more associated problems than children with CP without anomalies.

WHAT THIS PAPER ADDS

One in four children with cerebral palsy (CP) born at term or late preterm has a congenital anomaly. The added value of neuroimaging to detect central nervous system anomalies in children with CP. Children with anomalies have more severe motor impairments. More severe clinical manifestations are not explained by perinatal complications as indicated by low Apgar scores.

Congenital anomalies in cerebral palsy: where to from here?

Proportions of cases of cerebral palsy (CP) with congenital anomalies recorded in Australian CP registers range from 15% to 40%. The anomalies seen in CP are extremely variable. We have identified that CP registers often do not have quality data on congenital anomalies, necessitating linkage with congenital anomaly registers. However, a lack of unified processes and definitions in congenital anomaly registers and data collections means that linkages are complex, need to be carefully planned, and limitations acknowledged. Historically in CP research, congenital anomalies have been classified by International Classification of Disease codes, then combined into brain and other major and minor anomalies. Systems have been developed to classify congenital anomalies into aetiologically related groups, but such a classification has yet to be trialled in CP. It is anticipated that primary prevention of a small proportion of cases of CP is possible through the primary prevention of congenital anomalies, especially those due to teratogens. Owing to the anticipated low prevalence of each subgroup, global collaboration will be required to further these lines of enquiry.

Systematic Review of Cerebral Palsy Registries/Surveillance Groups: Relationships between Registry Characteristics and Knowledge Dissemination

The aims of this study were to provide a comprehensive summary of the body of research disseminated by Cerebral Palsy (CP) registries and surveillance programs from January 2009 through May 2014 in order to describe the influence their results have on our overall understanding of CP. Secondly, registries/surveillance programs and the work they produced were evaluated and grouped using standardized definitions and classification systems.

METHOD

A systematic review search in PubMed, CINAH and Embase for original articles published from 1 January 2009 to 20 May 2014 originating from or supported by population based CP registries and surveillance programs or population based national registries including CP were included. Articles were grouped by 2009 World CP Registry Congress aim, registry/surveillance program classification, geographical region, and the International Classification of Function, Disability and Health (ICF) domain. Registry variables were assessed using the ICF-CY classification.

RESULTS

Literature searches returned 177 articles meeting inclusion criteria. The majority (69%) of registry/surveillance program productivity was related to contributions as a Resource for CP Research. Prevention (23%) and Surveillance (22%) articles were other areas of achievement, but fewer articles were published in the areas of Planning (17%) and Raising the Profile of CP (2%). There was a range of registry/surveillance program classifications contributing to this productivity, and representation from multiple areas of the globe, although most of the articles originated in Europe, Australia, and Canada. The domains of the ICF that were primarily covered included body structures and function at the early stages of life. Encouragingly, a variety of CP registry/surveillance program initiatives included additional ICF domains of participation and environmental and personal factors.

INTERPRETATION

CP registries and surveillance programs, including novel non-traditional ones, have significantly contributed to the understanding of how CP affects individuals, families and society. Moving forward, the global CP registry/surveillance program community should continue to strive for uniformity in CP definitions, variables collected and consistency with international initiatives like the ICF so that databases can be consolidated for research use. Adaptation to new technologies can improve access, reduce cost and facilitate information transfer between registrants, researchers and registries/surveillance programs. Finally, increased efforts in documenting variables of individuals with CP into adulthood should be made in order to expand our understanding of CP across the lifespan.