Prospective and episodic memory in relation to hippocampal volume in adults with spina bifida myelomeningocele

Duration of fetoscopic spina bifida repair does not affect the central nervous system in fetal lambs

BACKGROUND

Prenatal spina bifida aperta repair improves neurologic outcomes yet comes with a significant risk of prematurity and uterine scar-related complications. To reduce such complications, different fetoscopic techniques, for example, with varying numbers of ports, are being explored. This has an effect on the duration of the procedure, potentially affecting central nervous system development. Both the condition and anesthesia can affect the central nervous system, particularly the hippocampus, a region crucial for prospective and episodic memory. Previous animal studies have shown the potential influence of anesthesia, premature delivery, and maternal surgery during pregnancy on this area.

OBJECTIVE

This study aimed to compare the effects of 2- vs 3-port fetoscopic spina bifida aperta repair in the fetal lamb model using neuron count of the hippocampus as the primary outcome.

STUDY DESIGN

Based on the hippocampal neuron count from previous lamb experiments, we calculated that we required 5 animals per group to achieve a statistical power of ≥ 80%. A spina bifida aperta defect was developed in fetal lambs at 75 days of gestation (term: 145 days). At 100 days, fetuses underwent either a 2-port or 3-port fetoscopic repair. At 143 days, all surviving fetuses were delivered by cesarean delivery, anesthetized, and transcardially perfused with a mixture of formaldehyde and gadolinium. Next, they underwent neonatal brain and spine magnetic resonance imaging after which these organs were harvested for histology. Hippocampus, frontal cortex, caudate nucleus, and cerebellum samples were immunostained to identify neurons, astrocytes, microglia, and markers associated with cell proliferation, myelination, and synapses. The degree of hindbrain herniation and the ventricular diameter were measured on magnetic resonance images and volumes of relevant brain and medulla areas were segmented.

RESULTS

Both treatment groups included 5 fetuses and 9 unoperated littermates served as normal controls. The durations for both skin-to-skin (341±31 vs 287±40 minutes; P=.04) and fetal surgery (183±30 vs 128±22; P=.01) were longer for the 2-port approach than for the 3-port approach. There was no significant difference in neuron density in the hippocampus, frontal cortex, and cerebellum. In the caudate nucleus, the neuron count was higher in the 2-port group (965±156 vs 767±92 neurons/mm2; P=.04). There were neither differences in proliferation, astrogliosis, synaptophysin, or myelin. The tip of the cerebellar vermis was closer to the foramen magnum in animals undergoing the 2-port approach than in animals undergoing the 3-port approach (-0.72±0.67 vs -2.47±0.91 mm; P=.009). There was no significant difference in the ratio of the hippocampus, caudate nucleus, or cerebellar volume to body weight. For the spine, no difference was noted in spine volume-to-body weight ratio for the lower (L1-L2), middle (L3-L4), and higher (L5-L6) levels. Compared with controls, in repaired animals, the cerebellar vermis tip laid closer to the foramen magnum, parietal ventricles were enlarged, and medulla volumes were reduced.

CONCLUSION

In the experimental spina bifida fetal lamb model, a 2-port repair took 40% longer than a 3-port repair. However, there was no indication of any relevant morphologic differences in the fetal brain.

Hydrocephalus and school-age neurodevelopmental outcomes in the management of myelomeningocele prenatal surgery trial: a secondary analysis

OBJECTIVE

The purpose of this secondary analysis was to assess the role of hydrocephalus on neurodevelopmental outcomes in a cohort of school-age children enrolled in the Management of Myelomeningocele Study (MOMS) clinical trial.

METHODS

The sample analyzed in this report consisted of 150 of 183 children aged 5-10 years (mean ± SD 7 years 8 months ± 1.2) who were randomly assigned between 20 and 26 weeks of gestational age to undergo either prenatal or postnatal surgery and were enrolled in the school-age follow-up study of MOMS. These 150 children (76 prenatal and 74 postnatal) were placed into three groups: no hydrocephalus (n = 22), unshunted hydrocephalus (n = 31), and shunted hydrocephalus (n = 97). Comparisons were made on the basis of measures of adaptive behavior, intelligence, reading and math skills, verbal and nonverbal memory, fine motor dexterity, and sensorimotor skills. Parent ratings of executive functions, inattention, and hyperactivity-impulsivity were also compared.

RESULTS

There were no statistically significant differences in neurodevelopmental outcomes between the groups with no hydrocephalus and unshunted hydrocephalus, or between the prenatal and postnatal groups with shunted hydrocephalus, so these groups were combined (no/unshunted vs shunted hydrocephalus). The no/unshunted group showed significantly better performance (p < 0.05) than the shunted group in terms of adaptive behavior, intelligence, verbal and nonverbal memory, reading skills (but not math), fine motor dexterity, sensorimotor skills (but not visual-motor integration), and inattention (but not hyperactivity-impulsivity or executive function ratings). An assessment of the prenatal surgery group showed that the combined no/unshunted group performed better than the shunted group in terms of adaptive behavior and verbal memory skills. Both the prenatal and postnatal surgery subgroups with unshunted hydrocephalus performed as well as the group with no hydrocephalus despite significantly enlarged ventricles.

CONCLUSIONS

Although the primary assessment of school-age outcomes in the MOMS clinical trial did not show better adaptive behavior and cognitive skills in the prenatal group, hydrocephalus and shunting were associated with poorer neurodevelopmental outcomes (both prenatal and postnatal groups). Disease severity and dynamic changes in hydrocephalus status may be the primary factors in the need for shunting and a major determinant of adaptive behavior and cognitive outcomes after prenatal surgery.

Potentially Preventable Hospitalizations Among Adults With Pediatric-Onset Disabilities

OBJECTIVE

To examine the risk of any and specific potentially preventable hospitalizations (PPHs) for adults with cerebral palsy (CP) or spina bifida (SB). We hypothesize that PPH risk is greater among adults with CP/SB compared with the general population.

PATIENTS AND METHODS

Using January 1, 2007, to December 31, 2017, national private administrative claims data (OptumInsight) in the United States, we identified adults with CP/SB (n=10,617). Adults without CP/SB were included as controls (n=1,443,716). To ensure a similar proportion in basic demographics, we propensity-matched our controls with cases in age and sex (n=10,617). Generalized estimating equation models were applied to examine the risk of CP/SB on PPHs. All models were adjusted for age, sex, race/ethnicity, health indicators, US Census Division data, and socioeconomic variables. Adjusted odds ratios were compared within a 4-year follow-up.

RESULTS

Adults with CP/SB had higher risk for any PPH (odds ratio [OR], 4.10; 95% CI, 2.31 to 7.31), and PPHs due to chronic obstructive pulmonary disease/asthma (OR, 1.85; CI, 1.23 to 2.76), pneumonia (OR, 3.01; 95% CI, 2.06 to 4.39), and urinary tract infection (OR, 6.48; 95% CI, 3.91 to 10.75). Cases and controls who had an annual wellness visit had lower PPH risk (OR, 0.52; 95% CI, 0.41 to 0.67); similarly, adults with CP/SB who had an annual wellness visit compared with adults with CP/SB who did not had lower odds of PPH (OR, 0.75; 95% CI, 0.60 to 0.94).

CONCLUSION

Adults with pediatric-onset disabilities are at a greater risk for PPHs. Providing better access to preventive care and health-promoting services, especially for respiratory and urinary outcomes, may reduce PPH risk among this patient population.

A spatio-temporal atlas of the developing fetal brain with spina bifida aperta

Background: Spina bifida aperta (SBA) is a birth defect associated with severe anatomical changes in the developing fetal brain. Brain magnetic resonance imaging (MRI) atlases are popular tools for studying neuropathology in the brain anatomy, but previous fetal brain MRI atlases have focused on the normal fetal brain. We aimed to develop a spatio-temporal fetal brain MRI atlas for SBA. Methods: We developed a semi-automatic computational method to compute the first spatio-temporal fetal brain MRI atlas for SBA. We used 90 MRIs of fetuses with SBA with gestational ages ranging from 21 to 35 weeks. Isotropic and motion-free 3D reconstructed MRIs were obtained for all the examinations. We propose a protocol for the annotation of anatomical landmarks in brain 3D MRI of fetuses with SBA with the aim of making spatial alignment of abnormal fetal brain MRIs more robust. In addition, we propose a weighted generalized Procrustes method based on the anatomical landmarks for the initialization of the atlas. The proposed weighted generalized Procrustes can handle temporal regularization and missing annotations. After initialization, the atlas is refined iteratively using non-linear image registration based on the image intensity and the anatomical land-marks. A semi-automatic method is used to obtain a parcellation of our fetal brain atlas into eight tissue types: white matter, ventricular system, cerebellum, extra-axial cerebrospinal fluid, cortical gray matter, deep gray matter, brainstem, and corpus callosum. Results: An intra-rater variability analysis suggests that the seven anatomical land-marks are sufficiently reliable. We find that the proposed atlas outperforms a normal fetal brain atlas for the automatic segmentation of brain 3D MRI of fetuses with SBA. Conclusions: We make publicly available a spatio-temporal fetal brain MRI atlas for SBA, available here:  https://doi.org/10.7303/syn25887675. This atlas can support future research on automatic segmentation methods for brain 3D MRI of fetuses with SBA.

A scoping review of cognition in spina bifida and its consequences for activity and participation throughout life

Aim

The aim of this scoping review was to summarise findings concerning cognitive characteristics in people with spina bifida and explain how cognitive factors influence activities and participation in different areas and stages of life.

Methods

PubMed, Psych INFO, ERIC, Scopus, CINAHL and the Cochrane Library were searched for English language papers published in 2000–2018. A total of 92 papers were selected and quality was assessed according to the McMaster criteria. The results were presented related to body functions, activity and participation from the International Classification of Function and Health, ICF.

Results

People with spina bifida tended to have a lower IQ than those without. The majority also had cognitive difficulties manifested in problems with language, perception, memory, executive and attentional functions. Those difficulties affected activity and participation in all life domains in ICF. This may affect medical adherence and responsibility and by extension the prevention of secondary complications.

Conclusion

It is important for caregivers, professionals and especially individuals with spina bifida themselves to understand and handle both physical and cognitive consequences in all life circumstances. Having insight into one’s own assets and difficulties paves the way to managing life challenges, which could enhance health, self‐management and participation in society.

Scribble Controls Social Motivation Behavior through the Regulation of the ERK/Mnk1 Pathway

Social behavior is a basic domain affected by several neurodevelopmental disorders, including ASD and a heterogeneous set of neuropsychiatric disorders. The SCRIB gene that codes for the polarity protein SCRIBBLE has been identified as a risk gene for spina bifida, the most common type of neural tube defect, found at high frequencies in autistic patients, as well as other congenital anomalies. The deletions and mutations of the 8q24.3 region encompassing SCRIB are also associated with multisyndromic and rare disorders. Nonetheless, the potential link between SCRIB and relevant social phenotypes has not been fully investigated. Hence, we show that Scribcrc/+ mice, carrying a mutated version of Scrib, displayed reduced social motivation behavior and social habituation, while other behavioral domains were unaltered. Social deficits were associated with the upregulation of ERK phosphorylation, together with increased c-Fos activity. Importantly, the social alterations were rescued by both direct and indirect pERK inhibition. These results support a link between polarity genes, social behaviors and hippocampal functionality and suggest a role for SCRIB in the etiopathology of neurodevelopmental disorders. Furthermore, our data demonstrate the crucial role of the MAPK/ERK signaling pathway in underlying social motivation behavior, thus supporting its relevance as a therapeutic target.

A Systematic Review of Cognitive Function in Adults with Spina Bifida

Background: Though much research has been done on the cognitive profiles of children, the abilities of patients with SBM as they age into adulthood are not well understood.Objective: Determine if adults with SBM have impairments in overall cognition, attention, executive function, and memory compared to typically developing adults or a standardized population mean.Methods: A medical librarian composed a search of spina bifida, adults, and cognitive function. 549 results were screened using title and abstract. Data were extracted using Covidence review software, including risk of bias assessments. 24 studies were included.Results: Memory impairments, notably working and prospective, have been reported. Results in other domains varied. Average VIQ or PIQ did not imply lack of impairment in other specific domains.Conclusion: Memory impairments should be accounted for and neuropsychological testing should be considered when providing care to adults with SBM. Future longitudinal cognitive aging and interventional studies are needed.

Prospective Memory Deficits in Multiple Sclerosis: Voxel-based Morphometry and Double Inversion Recovery Analysis

Objective Prospective memory (PM) is an important social cognitive function in everyday life. PM is one of the most affected cognitive domains in multiple sclerosis (MS) patients. Gray matter (GM) atrophy and plaques have been attracting attention for various cognitive impairments in MS patients. This study aimed to clarify the atrophic GM regions associated with PM deficits and investigate the relationship between the atrophic GM regions and GM plaques. Methods Twenty-one MS patients and 10 healthy controls (HCs) underwent neuropsychological tests and MRI. PM was assessed using subtests of the Rivermead Behavioural Memory Test. A lesion symptom analysis was performed using voxel-based morphometry (VBM). We then evaluated GM plaques in the corresponding areas using double inversion recovery (DIR). Results MS patients showed lower PM scores than HCs (p=0.0064). The GM volume of MS patients tended to be lower than those of HCs. VBM analyses revealed correlations of the PM score with the orbital part of the left inferior frontal gyrus, the left hippocampus, and the right parahippocampus. There was no GM plaque in the orbital part of the left inferior frontal gyrus and the right parahippocampus. Only one patient (4.8%) had GM plaque in the left hippocampus. Conclusion The left inferior frontal gyrus, the left hippocampus, and the right parahippocampus were associated with PM in MS, whereas these atrophic GM regions were not associated with GM plaque. Regardless of the location of plaques on DIR, both PM deficit and GM atrophy should be detected using neuropsychological tests and VBM in MS patients.

Neurobehavioral outcomes in patients with myelomeningocele

This paper describes some of the more common patterns in neurobehavioral deficits and their underlying neuroanatomical basis in myelomeningocele (MMC). Patients with MMC can face a lifetime of specific organ system dysfunction, chief among them spinal cord malformations, orthopedic issues, hydrocephalus, and urological disabilities. In addition, patients can experience specific patterns of neurobehavioral difficulties due to the changes in neuroanatomy associated with the open spinal defect. Although there is variability in these patterns, some trends have been described among MMC patients. It is thought that early recognition of these potential neurobehavioral deficits by treating neurosurgeons and other members of the treatment team could lead to earlier intervention and positively impact the overall outcome for patients. Neurodevelopmental and neurobehavioral follow-up assessments are recommended to help guide planning for relevant treatments or accommodations.

The impact of cerebral anomalies on cognitive outcome in patients with spina bifida: A systematic review

BACKGROUND

Spina bifida is the most common congenital birth defect affecting the central nervous system. Given the frequent association of cerebral anomalies, spina bifida is not a single developmental abnormality of the central nervous system. Patients with spina bifida typically perform below average on cognitive tasks. It has been hypothesized that associated cerebral anomalies as well negatively affect cognition in spina bifida patients.

OBJECTIVE

This study aims to review the impact of cerebral anomalies on cognitive outcome in patients with spina bifida.

METHODS

A systematic search of multiple databases, including Pubmed, Embase, Web of Science and The Cochrane Central Register of Controlled Trials, was performed. All relevant primary research articles were included. All included articles were methodologically evaluated using a critical appraisal checklist.

RESULTS

In total 27 articles were included in this systematic review. A significant impact of different cerebral anomalies on cognition was found. More specifically, hydrocephalus, Chiari malformation type II and anomalies of the corpus callosum, central executive network, default mode network, cortical thickness and gyrification, fornix, grey matter volume and total brain volume were found to have a significant impact on cognitive outcome. The presence of a CSF shunt was also negatively associated with cognition. The results on Chiari malformation type II decompression and CSF shunt complications are inconsistent.

CONCLUSION

Associated cerebral anomalies have a significant impact on cognitive outcome in patients with spina bifida. The interrelatedness of the different cerebral anomalies makes it difficult to distinguish their individual impact on cognition.

Long-Term Intellectual and Fine Motor Outcomes in Spina Bifida Are Related to Myelomeningocele Repair and Shunt Intervention History

OBJECTIVE

Lifespan outcomes of simultaneous versus sequential myelomeningocele repair and shunt placement or effects of repeated shunt revisions on specific domains of IQ or fine motor dexterity are largely unknown. The current study addressed these gaps in a large cohort of children and adults with spina bifida myelomeningocele (SBM).

METHODS

Participants between 7 and 44 years of age with SBM and shunted hydrocephalus were recruited from international clinics at two time points. Each participant completed a standardized neuropsychological evaluation that included estimates of IQ and fine motor dexterity. Simultaneous versus sequential surgical repair and number of shunt revisions were examined in relation to long-term IQ and fine motor scores.

RESULTS

Simultaneous myelomeningocele repair and shunting were associated with more frequent shunt revisions, as well as to lower Full Scale and verbal IQ scores, controlling for number of shunt revisions. More shunt revisions across study time points were associated with higher nonverbal IQ (NVIQ) scores. No effects were observed on fine motor dexterity.

CONCLUSIONS

Findings indicate generally greater influence of surgery type over shunt revision history on outcomes in well-managed hydrocephalus. Findings supported apparent, domain-specific benefits of sequential compared to simultaneous surgery across the lifespan in SBM. Higher NVIQ scores with greater number of additional shunt revisions across surgery type supported positive outcomes with effective surgical management for hydrocephalus.

Neuropsychological care guidelines for people with spina bifida

While the neuropsychological profile for individuals with Spina Bifida (SB) can vary, often certain patterns of strengths and weaknesses are evident across the lifespan. Understanding variability related to neural structure, genetics, ethnicity, and the environment is key to understanding individual differences in outcomes and can be vital in planning interventions and tracking progress. This article outlines the SB Guideline for the Neuropsychological Care of People with Spina Bifida from the 2018 Spina Bifida Association's Fourth Edition of the Guidelines for the Care of People with Spina Bifida and acknowledges that further research in SB neurocognitive profiles is warranted.

Cognitive control and associated neural correlates in adults with spina bifida myelomeningocele

OBJECTIVE

Accelerated aging can occur in adult survivors of neurodevelopmental disorders, but has been narrowly studied in spina bifida myelomeningocele (SBM). Since discrete aspects of cognitive control and related neural network macrostructure deteriorate in normal aging, the specificity and trajectory of cognition and neuropathology incurred across adulthood in SBM were examined.

METHOD

Adults (N = 120) with and without SBM completed working memory span and manipulation tasks, and an inhibitory control task. A subset (n = 53) underwent structural MRI. Effects of group, age, and their interaction on performance and select gray matter volumes were examined.

RESULTS

Adults with SBM had significantly poorer working memory accuracy and overall inhibitory control performance than typical peers. Age negatively predicted inhibitory control. Group × Age significantly interacted on span accuracy; advanced age related to diminished performance in typical adults, but not in adults with SBM. SBM related to disproportionately enlarged cortical and putamen and reduced hippocampus volumes. Group × Age significantly interacted on cortical, but not subcortical gray matter volumes. Dorsolateral prefrontal, hippocampus, and putamen volumes negatively correlated with cognitive performance.

CONCLUSIONS

Supporting previous literature, current findings elucidated a profile of executive impairment in SBM that was maintained in a parallel maturational trajectory to typical aging. Accelerated aging in cognitive control or subcortical gray matter was not supported in SBM. However, reductions in anterior and posterior cortical regions were exacerbated in older adults with SBM compared with typical peers. Overall results supported persistent anomalous neurodevelopmental maturation across the life span in SBM that related to diminished cognitive control. (PsycINFO Database Record

Spina bifida

Spina bifida is a birth defect in which the vertebral column is open, often with spinal cord involvement. The most clinically significant subtype is myelomeningocele (open spina bifida), which is a condition characterized by failure of the lumbosacral spinal neural tube to close during embryonic development. The exposed neural tissue degenerates in utero, resulting in neurological deficit that varies with the level of the lesion. Occurring in approximately 1 per 1,000 births worldwide, myelomeningocele is one of the most common congenital malformations, but its cause is largely unknown. The genetic component is estimated at 60-70%, but few causative genes have been identified to date, despite much information from mouse models. Non-genetic maternal risk factors include reduced folate intake, anticonvulsant therapy, diabetes mellitus and obesity. Primary prevention by periconceptional supplementation with folic acid has been demonstrated in clinical trials, leading to food fortification programmes in many countries. Prenatal diagnosis is achieved by ultrasonography, enabling women to seek termination of pregnancy. Individuals who survive to birth have their lesions closed surgically, with subsequent management of associated defects, including the Chiari II brain malformation, hydrocephalus, and urological and orthopaedic sequelae. Fetal surgical repair of myelomeningocele has been associated with improved early neurological outcome compared with postnatal operation. Myelomeningocele affects quality of life during childhood, adolescence and adulthood, posing a challenge for individuals, families and society as a whole. For an illustrated summary of this Primer, visit: http://go.nature.com/fK9XNa.