Preserved speed of processing and memory in infants with a history of moderate neonatal encephalopathy treated with therapeutic hypothermia

Co-occurring impairments in several domains of memory following neonatal hypoxic-ischaemic encephalopathy have real-life implications

BACKGROUND

Neonatal Hypoxic-Ischaemic Encephalopathy (HIE) increases the risk for neurodevelopmental impairment. Information on school-age memory function is limited in children who received hypothermia treatment (TH) for neonatal HIE.

OBJECTIVES

To evaluate memory function in school-aged children who had neonatal HIE and TH and survived without major neuromotor impairment.

METHOD

Fifty-one children with neonatal HIE and 41 typically developing (TD) peers participated. At age 6-8 years general cognitive abilities (FSIQ) were assessed with Wechsler Intelligence Scale for Children (WISC-V), immediate and delayed visual and verbal memory with Children's Memory Scale (CMS), everyday memory with Rivermead Behavioural Memory Test for Children (RBMT-C), and working memory with WISC-V. Real-life implications were assessed with Behavior Rating Inventory for Executive Function (BRIEF; Parent and Teacher). Group differences were examined and correlations calculated to assess associations between memory measures. Relationship maps illustrate co-occurring impairments.

RESULTS

FSIQ was in the normal range for both groups but significantly lower in the HIE group. Children with HIE had significantly more deficits in working memory (20.4 % vs 0 %), verbal immediate (20.0 % vs 2.5 %), verbal delayed (17.8 % vs 2.5 %), visual immediate (28.9 % vs 7.5 %), and everyday memory (38.8 % vs 5.6 %). Relationship maps identified more co-occurring clinical/borderline impairments in children with HIE (45.1 % vs 4.9 %) and more frequent clinical impairments in real-world memory measures.

CONCLUSION

Despite hypothermia treatment, and with general cognitive abilities in the normal range, children with neonatal HIE are at risk of memory impairments in multiple domains, affecting everyday functioning at home and school. Timely identification is important for individually targeted support.

Reduced Hippocampal Volumes in Children with History of Hypoxic Ischemic Encephalopathy after Therapeutic Hypothermia

Hypoxic ischemic encephalopathy (HIE) remains a significant cause of disability despite treatment with therapeutic hypothermia (TH). Many survive with more subtle deficits that affect daily functioning and school performance. We have previously shown an early indication of hippocampal changes in infants with HIE despite TH. The aim of this study was to evaluate the hippocampal volume via MRI and memory function at 5 years of age. A cohort of children followed from birth returned for a 5-year follow-up (n = 10 HIE treated with TH, n = 8 healthy controls). The children underwent brain MRI and neurodevelopmental testing to assess their brain volume, general development, and memory function. Children with HIE had smaller hippocampal volumes than the controls despite no differences in the total brain volume (p = 0.02). Children with HIE generally scored within the average range on developmental testing. Though there was no difference in the memory scores between these groups, there was a positive within-group correlation between the hippocampal volume and memory scores in children with HIE (sentence recall r = 0.66, p = 0.038). There was no relationship between newborn memory function and 5-year hippocampal size. Children with HIE treated with TH experienced significant and lasting changes to the hippocampus despite improvements in survival and severe disability. Future studies should target diminishing injury to the hippocampus to improve overall outcomes.

Preterm Brain Injury and Neurodevelopmental Outcomes: A Meta-analysis

CONTEXT

Preterm brain injuries are common; neurodevelopmental outcomes following contemporary neonatal care are continually evolving.

OBJECTIVE

To systematically review and meta-analyze neurodevelopmental outcomes among preterm infants after intraventricular hemorrhage (IVH) and white matter injury (WMI).

DATA SOURCES

Published and grey literature were searched across 10 databases between 2000 and 2021.

STUDY SELECTION

Observational studies reporting 3-year neurodevelopmental outcomes for preterm infants with IVH or WMI compared with preterm infants without injury.

DATA EXTRACTION

Study characteristics, population characteristics, and outcome data were extracted.

RESULTS

Thirty eight studies were included. There was an increased adjusted risk of moderate-severe neurodevelopmental impairment after IVH grade 1 to 2 (adjusted odds ratio 1.35 [95% confidence interval 1.05-1.75]) and IVH grade 3 to 4 (adjusted odds ratio 4.26 [3.25-5.59]). Children with IVH grade 1 to 2 had higher risks of cerebral palsy (odds ratio [OR] 1.76 [1.39-2.24]), cognitive (OR 1.79 [1.09-2.95]), hearing (OR 1.83 [1.03-3.24]), and visual impairment (OR 1.77 [1.08-2.9]). Children with IVH grade 3 to 4 had markedly higher risks of cerebral palsy (OR 4.98 [4.13-6.00]), motor (OR 2.7 [1.52-4.8]), cognitive (OR 2.3 [1.67-3.15]), hearing (OR 2.44 [1.42-4.2]), and visual impairment (OR 5.42 [2.77-10.58]). Children with WMI had much higher risks of cerebral palsy (OR 14.91 [7.3-30.46]), motor (OR 5.3 [3-9.36]), and cognitive impairment (OR 3.48 [2.18-5.53]).

LIMITATIONS

Heterogeneity of outcome data.

CONCLUSIONS

Mild IVH, severe IVH, and WMI are associated with adverse neurodevelopmental outcomes. Utilization of core outcome sets and availability of open-access study data would improve our understanding of the nuances of these outcomes.