Association of Gestational Age at Birth and Changes on MRI With Prevalence and Spectrum of Comorbidities in Children With Cerebral Palsy.

BACKGROUND AND OBJECTIVES: For individuals with cerebral palsy (CP) and caregivers, comorbidities may be a greater challenge than neuromotor impairment. Clinicians may make assumptions regarding risk of comorbidities based simply on term vs preterm birth, but this has not been well examined. To better understand factors affecting comorbidity pattern, we investigated the relationship between gestational age (GA) and imaging pattern on the presence of specific comorbidities. METHODS: This is a cross-sectional study of data extracted from the Canadian Cerebral Palsy Registry of children with CP. Multivariable analysis was used to evaluate the relationship between brain injury, GA, and comorbidities. Comorbidities included in the analysis were communication, cognitive, visual, and auditory impairment, seizures in the past year, and gavage feeding. Each comorbidity was assessed as a separate nonexclusive outcome, with GA, MRI pattern, birth weight, postneonatal insult, 5-minute Apgar score, and male sex considered as potential modifiers. RESULTS: The only comorbidity affected by GA on multivariable analysis was seizures within the past year that were more prevalent in term children (odds ratio [OR] 1.1 95% CI 1.0-1.2) and was also affected by Apgar score (OR 0.9 95% CI 0.85-0.94), but not MRI pattern. MRI pattern appeared important for communication impairment (deep gray OR 4.2 95% CI 1.8-10.0; total brain injury OR 8.5, 95% CI 3.2-22.6; malformation OR 2.7, 95% CI 1.3-5.7) and cognitive impairment (deep gray OR 5.6, 95% CI 2.4-13.2; total brain injury OR 10.1, 95% CI 4.0-25.3; malformation OR 3.3, 95% CI 1.6-6.8; watershed OR 3.6, 95% CI 1.4-8.9). Focal injury compared with normal MRI was associated with reduced odds of visual impairment (OR 0.24, 95% CI 0.12-0.48), auditory impairment (OR 0.2195% CI 0.10-0.46) and communication impairment (OR 0.46, 95% CI 0.26-0.82), and overall number of comorbidities (coefficient -0.73, 95% CI -1.2 to -0.31). The number of comorbidities was increased by total brain injury pattern (coefficient 0.65, 95% CI 0.15-1.13) and reduced by focal brain injury (coefficient -0.73, 95% CI -1.2 to -0.31) and increasing 5-minute Apgar score (coefficient -0.11, 95% CI -0.16 to -0.07). DISCUSSION: In those with brain injuries sufficient to cause CP, development of additional comorbidities is less affected by GA at birth and more related to the underlying cause of CP as reflected by MRI patterns.

Risk Factors for Perinatal Arterial Ischemic Stroke: A Machine Learning Approach.

BACKGROUND AND OBJECTIVES: Perinatal arterial ischemic stroke (PAIS) is a focal vascular brain injury presumed to occur between the fetal period and the first 28 days of life. It is the leading cause of hemiparetic cerebral palsy. Multiple maternal, intrapartum, delivery, and fetal factors have been associated with PAIS, but studies are limited by modest sample sizes and complex interactions between factors. Machine learning approaches use large and complex data sets to enable unbiased identification of clinical predictors but have not yet been applied to PAIS. We combined large PAIS data sets and used machine learning methods to identify clinical PAIS factors and compare this data-driven approach with previously described literature-driven clinical prediction models. METHODS: Common data elements from 3 registries with patients with PAIS, the Alberta Perinatal Stroke Project, Canadian Cerebral Palsy Registry, International Pediatric Stroke Study, and a longitudinal cohort of healthy controls (Alberta Pregnancy Outcomes and Nutrition Study), were used to identify potential predictors of PAIS. Inclusion criteria were term birth and idiopathic PAIS (absence of primary causative medical condition). Data including maternal/pregnancy, intrapartum, and neonatal factors were collected between January 2003 and March 2020. Common data elements were entered into a validated random forest machine learning pipeline to identify the highest predictive features and develop a predictive model. Univariable analyses were completed post hoc to assess the relationship between each predictor and outcome. RESULTS: A machine learning model was developed using data from 2,571 neonates, including 527 cases (20%) and 2,044 controls (80%). With a mean of 21 features selected, the random forest machine learning approach predicted the outcome with approximately 86.5% balanced accuracy. Factors that were selected a priori through literature-driven variable selection that were also identified as most important by the machine learning model were maternal age, recreational substance exposure, tobacco exposure, intrapartum maternal fever, and low Apgar score at 5 minutes. Additional variables identified through machine learning included in utero alcohol exposure, infertility, miscarriage, primigravida, meconium, spontaneous vaginal delivery, neonatal head circumference, and 1-minute Apgar score. Overall, the machine learning model performed better (area under the curve [AUC] 0.93) than the literature-driven model (AUC 0.73). DISCUSSION: Machine learning may be an alternative, unbiased method to identify clinical predictors associated with PAIS. Identification of previously suggested and novel clinical factors requires cautious interpretation but supports the multifactorial nature of PAIS pathophysiology. Our results suggest that identification of neonates at risk of PAIS is possible.

Risk Factors and Outcomes for Cerebral Palsy With Hypoxic-Ischemic Brain Injury Patterns Without Documented Neonatal Encephalopathy.

BACKGROUND AND OBJECTIVES: Perinatal hypoxic-ischemic brain injury is a leading cause of term-born cerebral palsy, the most common lifelong physical disability. Diagnosis is commonly made in the neonatal period by the combination of neonatal encephalopathy (NE) and typical neuroimaging findings. However, children without a history of neonatal encephalopathy may present later in childhood with motor disability and neuroimaging findings consistent with perinatal hypoxic-ischemic injury. We sought to determine the prevalence of such presentations using the retrospective viewpoint of a large multiregional cerebral palsy registry. METHODS: Patient cases were extracted from the Canadian Cerebral Palsy Registry with gestational age >36 weeks, an MRI pattern consistent with hypoxic-ischemic injury (HII, acute total, partial prolonged, or combined), and an absence of postnatal cause for HII. Documentation of NE was noted. Maternal-fetal risk factors, labor and delivery, neonatal course, and clinical outcome were extracted. Comparisons were performed using χ2 tests and multivariable logistic regression with multiple imputation. Propensity scores were used to assess for bias. RESULTS: Of the 170 children with MRI findings typical for HII, 140 (82.4%, 95% confidence interval [CI] 75.7%-87.7%) had documented NE and 29 (17.0%, 95% CI 11.7%-23.6%) did not. The group without NE had more abnormalities of amniotic fluid volume (odds ratio [OR] 15.8, 95% CI 1.2-835), had fetal growth restriction (OR 4.7, 95% CI 1.0-19.9), had less resuscitation (OR 0.03, 95% CI 0.007-0.08), had higher 5-minute Apgar scores (OR 2.2, 95% CI 1.6-3.0), were less likely to have neonatal seizures (OR 0.004, 95% CI 0.00009-0.03), and did not receive therapeutic hypothermia. MRI was performed at a median 1.1 months (interquartile range [IQR] 0.67-12.8 months) for those with NE and 12.2 months (IQR 6.6-25.9) for those without (p = 0.011). Patterns of injury on MRI were seen in similar proportions. Hemiplegia was more common in those without documented NE (OR 5.1, 95% CI 1.5-16.1); rates of preserved ambulatory function were similar. DISCUSSION: Approximately one-sixth of term-born children with an eventual diagnosis of cerebral palsy and MRI findings consistent with perinatal hypoxic-ischemic brain injury do not have documented neonatal encephalopathy, which was associated with abnormalities of fetal growth and amniotic fluid volume, and a less complex neonatal course. Long-term outcomes seem comparable with their peers with encephalopathy. The absence of documented neonatal encephalopathy does not exclude perinatal hypoxic-ischemic injury, which may have occurred antenatally and must be carefully evaluated with MRI.

Evaluation of Individuals with Non-Syndromic Global Developmental Delay and Intellectual Disability.

Global Developmental Delay (GDD) and Intellectual Disability (ID) are two of the most common presentations encountered by physicians taking care of children. GDD/ID is classified into non-syndromic GDD/ID, where GDD/ID is the sole evident clinical feature, or syndromic GDD/ID, where there are additional clinical features or co-morbidities present. Careful evaluation of children with GDD and ID, starting with detailed history followed by a thorough examination, remain the cornerstone for etiologic diagnosis. However, when initial history and examination fail to identify a probable underlying etiology, further genetic testing is warranted. In recent years, genetic testing has been shown to be the single most important diagnostic modality for clinicians evaluating children with non-syndromic GDD/ID. In this review, we discuss different genetic testing currently available, review common underlying copy-number variants and molecular pathways, explore the recent evidence and recommendations for genetic evaluation and discuss an approach to the diagnosis and management of children with non-syndromic GDD and ID.

Randomized placebo-controlled crossover trial of memantine in children with epileptic encephalopathy.

Memantine is an N-methyl-D-aspartate receptor antagonist, approved for dementia treatment. There is limited evidence of memantine showing benefit for paediatric neurodevelopmental phenotypes, but no randomized placebo-controlled trials in children with developmental and epileptic encephalopathy. In this randomized double-blind placebo-controlled crossover trial (Trial registration: https://clinicaltrials.gov/ct2/show/NCT03779672), patients with developmental and epileptic encephalopathy received memantine and placebo, each for a 6-week period separated by a 2-week washout phase. Electroencephalography, seizure diary, patient caregivers' global impression, serum inflammatory markers and neuropsychological evaluation were performed at baseline and after each treatment phase. The primary outcome measure was classification as a 'responder', defined as ≥2 of: >50% seizure frequency reduction, electroencephalography improvement, caregiver clinical impression improvement or clear neuropsychological testing improvement. Thirty-one patients (13 females) enrolled. Two patients withdrew prior to initiating medication and two (twins) had to be removed from analysis. Of the remaining 27 patients, nine (33%) were classified as responders to memantine versus two (7%) in the placebo group (P < 0.02). Electroencephalography improvement was seen in eight patients on memantine compared to two on placebo (P < 0.04). Seizure improvement was observed in eight patients on memantine and two on placebo (P < 0.04). Caregivers reported overall clinical improvement in 10 patients on memantine compared to seven on placebo (not significant). Statistical analysis of neuropsychological evaluation suggested improvements in symptoms of attention-deficit hyperactivity disorder and autism. Memantine is a safe and effective treatment for children with developmental and epileptic encephalopathy, having the potential to improve both seizure control and cognitive function.

Risk Factors for Term-Born Periventricular White Matter Injury in Children With Cerebral Palsy: A Case-Control Study.

OBJECTIVE: The aim of this study was to identify possible risk factors associated with term-born children with cerebral palsy (CP) and periventricular white matter injury (PVWMI) on imaging. METHODS: This is a case-controlled study restricted to term-born children with CP with the cases extracted from the Canadian Cerebral Palsy Registry and controls from Alberta Pregnancy Outcomes and Nutrition (APrON) study. A diagnosis of PVWMI was performed based on expert categorization of MRI reports. Risk factor variables were selected a priori; these included pregnancy complications, antenatal toxin exposure, perinatal infection, sex, small for gestational age, and perinatal adversity (i.e., neonatal encephalopathy presumably on the basis of intrapartum hypoxia-ischemia). We used multivariable analyses to calculate odds ratios (ORs) and their 95% CIs. RESULTS: A total of 160 cases (7.06% of the registry sample) were compared with 1,950 controls. Of the term-born PVWMI participants, 59.4% were male and 13.5% were born to mothers of extreme maternal age. Multivariable analysis of each risk factor controlled for weight showed PVWMI is associated with pregnancy complications (OR = 3.35; 95% CI = 2.23-4.94), antenatal toxin exposure (OR = 2.45; 95% CI = 1.67-3.55), perinatal infection (OR = 3.61; 95% CI = 1.96-6.29), and perinatal adversity (OR = 2.03; 95% CI = 1.42-2.94). Term-born male participants were not more likely to experience PVWMI compared with female participants (OR = 1.37; 95% CI = 0.98-1.93). Multiple regression analyses suggested independent associations between PVWMI and pregnancy complications (OR = 3.75; 95% CI 2.46-5.62), antenatal toxin exposure (OR = 2.80; 95% CI 1.88-4.12), perinatal infection (OR = 4.62; 95% CI 2.46-8.42), and perinatal adversity (OR = 2.49; 95% CI = 1.71-3.69). DISCUSSION: Risk factors such as pregnancy complications, antenatal toxin exposure, perinatal infection, and perinatal adversity are associated with PVWMI in term-born children, suggesting perhaps variable interactions between antenatal and perinatal factors to yield this under-recognized CP phenotype.

Copy number variation in genetic epilepsy with febrile seizures plus.

AIM: Genetic epilepsy with febrile seizures plus (GEFS+) is a familial epilepsy syndrome in which affected individuals may have a variety of epilepsy phenotypes, the most common being febrile seizures (FS) and febrile seizures plus (FS+). We investigated the possible contribution of copy number variation to GEFS+. METHOD: We searched our epilepsy research database for patients in GEFS + families who underwent chromosomal microarray analysis. We reviewed the clinical features and results of genetic testing in these families. RESULTS: Of twelve families with available microarray data, four had at least one copy number variant (CNV) identified. In Family 1, the proband had a maternally-inherited 15q11.2 deletion. In Family 5, four different CNVs were identified, variably present in the affected individuals; this included a 19p13.3 deletion affecting CACNA1A. Finally, in both Families 9 and 10, the proband had Dravet syndrome with pathogenic SCN1A variant, as well as a CNV (10q11.22 duplication in Family 9 and 22q11.2 deletion in Family 10). INTERPRETATION: The significance of these specific variants is difficult to precisely determine; however, there appeared to be an overrepresentation of CNVs in this small cohort. These findings suggest chromosomal microarray analysis could have clinical utility as part of the workup in GEFS + families.

Sudden unexpected death in GEFS+ families with sodium channel pathogenic variants.

We aimed to describe families with genetic epilepsy with febrile seizures plus (GEFS+) in which individuals suffered sudden unexpected death. The Epilepsy Pharmacogenomics Research Database was reviewed for GEFS + families in which at least one individual had suffered sudden death, and two families were identified. In Family A, five males had febrile seizures and one girl had febrile seizures plus. The latter died at 22 months of age and was classified as definite SUDEP. Molecular genetic testing identified a pathogenic SCN1B variant. In Family B, two brothers had recurrent focal status epilepticus with fever, and were classified as having atypical multifocal Dravet syndrome. The elder brother died suddenly at seven years of age, but was not classified SUDEP because the event occurred following status epilepticus. SCN1A sequencing in the surviving brother identified a likely pathogenic variant. These two cases of sudden death in GEFS + families with likely pathogenic variants in sodium channel genes demonstrate that sudden death may occur in GEFS+, even with mild phenotypes. The presence of sodium channel variants may have further increased the sudden death risk, particularly in the case of SCN1B, a gene which has also been associated with cardiac conditions including Brugada syndrome and long QT.

Developmental outcomes in children with congenital cerebellar malformations.

AIM: Neurodevelopmental outcomes in children with congenital cerebellar malformations (CCMs) remain poorly defined. We aimed to assess whether specific neuroimaging features in CCM patients correlate with neurodevelopmental outcomes. METHOD: Hospital records and neuroimaging of 67 children with CCMs were systematically reviewed. Logistic regression analyses were used to assess associations between specific imaging features and neurodevelopmental outcomes. RESULTS: CCM categories were distributed as follows: 28 percent isolated vermis hypoplasia (n=19), 28 percent global cerebellar hypoplasia (n=19), 15 percent Dandy-Walker malformation (n=10), 13 percent pontocerebellar hypoplasia (PCH, n=9), 9 percent molar tooth malformation (n=6), 3 percent rhombencephalosynapsis (n=2), and 3 percent unilateral cerebellar malformation (n=2). Overall, 85 percent (55/65) of the cohort had global developmental delay (GDD). Intellectual disability was present in 61 percent (27/43) and autism spectrum disorder (ASD) in 12 percent (6/52). Adjusting for supratentorial malformations and presence of genetic findings, severe GDD was associated with cerebellar hypoplasia (p=0.049) and PCH (p=0.030), whereas children with vermis hypoplasia were less likely to have severe GDD (p=0.003). Presence of supratentorial abnormalities was not significantly associated with worse neurodevelopmental outcome but was associated with epilepsy. INTERPRETATION: Children with CCMs have high prevalence of neurodevelopmental deficits. Specific features on imaging can aid prognostication and establish early intervention strategies. WHAT THIS PAPER ADDS: Atypical long-term neurodevelopmental outcome is very common in patients with congenital cerebellar malformations (CCMs). Involvement of the brainstem and cerebellar hemispheres predicts more severe neurodevelopmental disability. Most patients with vermis hypoplasia have language delay but are verbal. Supratentorial abnormalities are not significantly associated with worse neurodevelopmental outcome but are associated with epilepsy. Comorbidities are common in CCMs, especially ophthalmological issues in cerebellar hypoplasia and sensorineural hearing loss in pontocerebellar hypoplasia.

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.

Two Novel KCNQ2 Mutations in 2 Families With Benign Familial Neonatal Convulsions.

Benign familial neonatal convulsion is a rare autosomal dominant inherited epilepsy syndrome characterized by unprovoked seizures in the first few days of life, normal psychomotor development, and a positive intergenerational family history of neonatal seizures. Over 90% of the affected individuals have inherited causal mutations in KCNQ2, which encodes for the potassium voltage-gated channel subfamily Q, member 2. Mutations in KCNQ2 are also associated with a severe neonatal encephalopathy phenotype associated with poor seizure control and neurodevelopmental deficits. The authors report the clinical presentations, response to medication, and intrafamilial phenotypic variability in 2 families with benign familial neonatal convulsions, carrying previously unreported heterozygous missense mutations, c.1066C>G (p.Leu356Val) and c.1721G

Clinical and Radiologic Spectrum of Septo-optic Dysplasia: Review of 17 Cases.

We retrospectively reviewed the clinical and radiologic characteristics of 17 individuals with septo-optic dysplasia (SOD) and attempted to identify correlations between imaging findings, clinical features, and neurodevelopmental outcome. Surprisingly, only 1 (6%) individual was classified as classic SOD (with septum pellucidum/corpus callosum dysgenesis), 3 (18%) as SOD-like (with normal septum pellucidum/corpus callosum) and the majority, 13 (76%), as SOD-plus (with cortical brain malformation). Cortical abnormalities included schizencephaly, polymicrogyria, and gray matter heterotopias. All individuals had optic nerve hypoplasia, 11 (65%) had endocrinologic deficits, and 13 (76%) had abnormal cerebral midlines. Seven individuals (41%) had all 3 features. Neurodevelopmental outcome was abnormal in 13 (78%), ranging from mild to severe developmental delay. Individuals with SOD-plus did not have more severe neurologic deficits than individuals with classic or SOD-like subgroups. Thus, SOD is clinically and radiologically heterogeneous, and cortical abnormalities are very common. Neurodevelopmental deficits are very prevalent, and of wide-ranging severity.

The 'ouR-HOPE' approach for ethics and communication about neonatal neurological injury.

Predicting neurological outcomes of neonates with acute brain injury is an essential component of shared decision-making, in order to guide the development of treatment goals and appropriate care plans. It can aid parents in imagining the child's future, and guide timely and ongoing treatment decisions, including shifting treatment goals and focusing on comfort care. However, numerous challenges have been reported with respect to evidence-based practices for prognostication such as biases about prognosis among clinicians. Additionally, the evaluation or appreciation of living with disability can differ, including the well-known disability paradox where patients self-report a good quality of life in spite of severe disability. Herein, we put forward a set of five practice principles captured in the "ouR-HOPE" approach (Reflection, Humility, Open-mindedness, Partnership, and Engagement) and related questions to encourage clinicians to self-assess their practice and engage with others in responding to these challenges. We hope that this proposal paves the way to greater discussion and attention to ethical aspects of communicating prognosis in the context of neonatal brain injury.

Perinatal Regionalization and Implications for Long-Term Health Outcomes in Cerebral Palsy.

BACKGROUND: Perinatal regionalization is linked to improved neonatal outcomes; however, the effects on long-term outcomes in cerebral palsy (CP) are not known. We estimate the effect of highest levels of neonatal care available at delivery on the risk of developing a nonambulatory CP status. METHODS: Children with CP born in Quebec from the Canadian CP Registry excluding postneonatal causes were included (N=360). We estimate the effect of level of care available at delivery on risk of nonambulatory status among children with CP using propensity score matching and instrumental variables methods to adjust for differences in case mix among the three groups of hospitals. The outcome variable is an indicator for CP nonambulation assigned according to Gross Motor Function Classification System (levels IV and V). This study used data that predated therapeutic hypothermia in Quebec. RESULTS: Propensity score estimates of change in the adjusted risk of having a nonambulatory CP status because of birth at level II versus level I is -0.081, 95% confidence interval (CI; -0.2182 to 0.0562); level III versus level I is -0.072 95% CI (-0.225 to 0.08), and level III versus level II is 0.157 95% CI (0.027 to 0.286). CONCLUSIONS: Differences in levels of neonatal care available at hospital where the delivery was carried out are not associated with the risk of a nonambulatory CP phenotype. This suggests that level of care and associated medical technology within the Quebec regionalized neonatal-perinatal system is used efficiently because it does not offer any further marginal benefit in the reduction of severe CP outcomes. The system works well as it is, which is supportive of the perinatal regionalization. The success of the neonatal resuscitation program and referral of high-risk births to regional hospitals with sufficient obstetric and perinatal competence and resources may contribute to this lack of variability.

Cerebral palsy after neonatal encephalopathy: do neonates with suspected asphyxia have worse outcomes?

AIM: We sought to investigate how brain injury and severity, and neurological subtype of cerebral palsy (CP) differed in term-born children with CP after neonatal encephalopathy, between those with suspected birth asphyxia and those without. METHOD: Using the Canadian CP Registry, which included 1001 children, those with CP born at ≥ 36 wks after moderate or severe neonatal encephalopathy, were dichotomized according to the presence or absence of suspected birth asphyxia. Gross Motor Function Classification System (GMFCS) scores, neurological subtypes, comorbidities, and magnetic resonance imaging findings were compared. RESULTS: Of the 147 term-born children with CP (82 males, 65 females; median age 37 months, interquartile range [IQR] 26-52.5) who after moderate or severe neonatal encephalopathy had the required outcome data, 61 (41%) met criteria for suspected birth asphyxia. They had a higher frequency of non-ambulatory GMFCS status (odds ratio [OR] 3.4, 95% confidence interval [CI] 1.72-6.8), spastic quadriplegia (OR 2.8, 95% CI 1.4-5.6), non-verbal communication skills impairment (OR 4.2, 95% CI 2.0-8.6), isolated deep grey matter injury (OR 4.1, 95% CI 1.8-9.5), a lower frequency of spastic hemiplegia (OR 0.17, 95% CI 0.07-0.42), focal injury (OR 0.20; 95% CI 0.04-0.93), and more comorbidities (p=0.017) than those who did not meet criteria. INTERPRETATION: Term-born children who develop CP after neonatal encephalopathy with suspected birth asphyxia have a greater burden of disability than those without suspected birth asphyxia.

Clinically relevant copy number variations detected in cerebral palsy.

Cerebral palsy (CP) represents a group of non-progressive clinically heterogeneous disorders that are characterized by motor impairment and early age of onset, frequently accompanied by co-morbidities. The cause of CP has historically been attributed to environmental stressors resulting in brain damage. While genetic risk factors are also implicated, guidelines for diagnostic assessment of CP do not recommend for routine genetic testing. Given numerous reports of aetiologic copy number variations (CNVs) in other neurodevelopmental disorders, we used microarrays to genotype a population-based prospective cohort of children with CP and their parents. Here we identify de novo CNVs in 8/115 (7.0%) CP patients (∼1% rate in controls). In four children, large chromosomal abnormalities deemed likely pathogenic were found, and they were significantly more likely to have severe neuromotor impairments than those CP subjects without such alterations. Overall, the CNV data would have impacted our diagnosis or classification of CP in 11/115 (9.6%) families.

Cerebral Palsy after Neonatal Encephalopathy: How Much Is Preventable?

OBJECTIVES: To determine the expected proportion of term cerebral palsy (CP) after neonatal encephalopathy (NE) that could theoretically be prevented by hypothermia and elucidate the perinatal factors associated with CP after NE in those who do not meet currently used clinical criteria required to qualify for hypothermia ("cooling criteria"). STUDY DESIGN: Using the Canadian CP Registry, we categorized children born at ≥ 36 weeks with birth weight ≥ 1800 g with CP after moderate or severe NE according to the presence or absence of cooling criteria. Maternal, perinatal, postnatal, and placental factors were compared between the 2 groups. A number needed to treat of 8 (95% CI 6-17) to prevent one case of CP was used for calculations. RESULTS: Among the 543 term-born children with CP, 155 (29%) had moderate or severe NE. Sixty-four of 155 (41%) met cooling criteria and 91 of 155 (59%) did not. Shoulder dystocia was more common in those who did not meet cooling criteria (OR 8.8; 95% CI 1.1-71.4). Low birth weights (20% of all singletons), small placentas (42%), and chorioamnionitis (13%) were common in both groups. CONCLUSIONS: The majority of children with CP after NE did not meet cooling criteria. An estimated 5.1% (95% CI 2.4%-6.9%) of term CP after NE may be theoretically prevented with hypothermia. Considering shoulder dystocia as an additional criterion may help recognize more neonates who could potentially benefit from cooling. In all cases, a better understanding of the antenatal processes underlying NE is essential in reducing the burden of CP.

Somatosensory evoked potentials in neonates with hypoxic-ischemic encephalopathy treated with hypothermia.

OBJECTIVE: Somatosensory evoked potentials (SEPs) are reported to have high positive predictive value (PPV) for neurodevelopmental impairment (NDI) in neonates with moderate or severe hypoxic-ischemic encephalopathy (HIE). Our objective was to assess if this predictive value remains high with the use of therapeutic hypothermia. METHODS: A cohort of HIE neonates treated with hypothermia was recruited between September 2008 and September 2010. SEPs were elicited after hypothermia and classified as bilateral absent N19, abnormal N19 (i.e., delayed or unilateral absent), or normal. Qualitative evaluation of MRI was also performed. The primary outcome was moderate or severe NDI around 2 years of age. RESULTS: SEPs were performed after hypothermia in 26 of 34 neonates submitted to hypothermia with adequate follow-up at a median day of life 11 (IQR 9, 13). Twenty-three (88%) had moderate encephalopathy. Eleven neonates (42%) had bilateral absent N19, 4 of whom had NDI, while fifteen neonates (58%) had either abnormal or normal N19, of whom only one had NDI. SEPs thus had a PPV of 0.36 (4/11) and a negative predictive value (NPV) of 0.93 (14/15). Eighteen neonates (69%) had brain injury on MRI. MRI thus had a PPV of 0.28 (5/18) and an NPV of 1.00 (8/8). CONCLUSIONS: Neonates with HIE treated with hypothermia with bilateral absent N19 potentials may have a better prognosis than reported in the pre-hypothermia era. MRI also had a low PPV and high NPV. SEPs should be interpreted with caution in this new population and need to be re-evaluated in larger studies.

Autism spectrum disorder in a term birth neonatal intensive care unit population.

BACKGROUND: Nonspecific perinatal risk factors have been revealed to be associated with the development of autism spectrum disorder. However, term at-risk infants, as a distinct population, are underrepresented in the literature. This study examines the incidence and neonatal risk factors for autism spectrum disorder in term neonatal intensive care unit survivors. METHODS: We performed a retrospective analysis from a single university-practice database of neonates admitted to the neonatal intensive care unit and followed by a single pediatric neurologist. Term infants (≥ 37 weeks), born between 1991 and 2011, with at least 2 years (or 1 year if found to be neurologically normal) of follow-up were included. Principle outcomes were autism spectrum disorder, cerebral palsy, global developmental delay, and epilepsy. RESULTS: One hundred eighty infants were included from a database of 564 neonates. Twelve (6.6%) developed autism spectrum disorder, 53 (29.4%) cerebral palsy, 77 (42.7%) global developmental delay, and 47 (26.1%) epilepsy. Seventy-one (39.4%) developed no adverse outcomes. Nine patients with autism spectrum disorder (75%) were diagnosed with at least one other adverse outcome. No neonatal or perinatal variables were evident to be significantly associated with later autism spectrum disorder. CONCLUSIONS: In term neonatal intensive care unit survivors, autism spectrum disorder occurs at a greater frequency than in the general population and often develops alongside comorbid conditions. This highlights the importance of screening term neonatal intensive care unit survivors for autism spectrum disorder, particularly when comorbidities are present.