The role of ultrasonography in the diagnosis of fetal isolated complete agenesis of the corpus callosum: a long-term prospective study

Partial agenesis of the corpus callosum: Prenatal ultrasound characteristics, associations, and outcome

INTRODUCTION

To investigate prenatal ultrasound characteristics, associated abnormalities, and outcomes of partial agenesis of the corpus callosum (pACC).

MATERIAL AND METHODS

A total of 118 fetuses with pACC diagnosed using prenatal ultrasound were studied, and their prenatal ultrasound characteristics, associated abnormalities, genetics, and outcomes were collected. The fetuses were categorized into three groups according to gestational age: <24 weeks, 24-28 weeks, and >28 weeks, and the brain transverse plane ultrasound signs were compared among the three groups.

RESULTS

Prenatal ultrasound revealed the presence of abnormal cavum septi pellucidi (CSP), distention of the interhemispheric fissure (IF), dilated and elevated third ventricle (TV), and ventriculomegaly in 102 (86.4%), 91 (77.1%), 56 (47.4%), and 42 (35.6%) cases, respectively, in the transverse plane of the brain. Among the cases with dilatation and elevation of the TV, 38 (67.8%) showed posterior displacement, manifested by a cystic mass in the midline that communicated with the TV. There were statistically significant differences in the incidence of ventriculomegaly and abnormal CSP among the three groups at <24 weeks, 24-28 weeks, and >28 weeks. However, there were no statistically significant differences in the distention of the IF and TV among the three groups. Moreover, our cohort studies demonstrated that 32.2% (38/118), 18.6% (22/118), and 17.8% (21/118) of the cases were associated with intracranial, extracranial, and intra-extracranial anomalies, respectively. The most common intracranial and extracranial anomalies were cerebral cortical dysplasia and cardiovascular anomalies. Genetic analysis demonstrated that 37.8% (17/41) of patients had genetic abnormalities. 25% (4/16) and 52% (13/25) of isolated and non-isolated pACC cases showed genetic abnormalities. Eight isolated cases were born, with an average age of 28 months, and their neurological development was normal.

CONCLUSIONS

Abnormal CSP was the most common indirect sign of pACC. A cystic mass in the midline communicating with the TV can be another indirect sign of a pACC. pACC is likely to be accompanied by intracranial and extracranial abnormalities. The detection rate of genetic abnormalities was higher in non-isolated pACC cases than in isolated cases. Isolated pACC has a good prognosis but requires long-term follow-up of neurological development.

Neuropsychological profiles of children with agenesis of the corpus callosum: A scoping review

AIM

To understand the wide variety of clinical outcomes in children with agenesis of the corpus callosum (AgCC) and examine evidence for the proposed neuropsychological syndrome reported in adults with primary AgCC.

METHOD

PsycINFO, PsycArticles, Medline, Embase, and Web of Science (January 2007-November 2021) were searched to identify studies reporting on cognitive or neuropsychological outcome in children with AgCC aged up to 18 years. Twenty-three articles investigating the cognitive profile were found; their methodology was evaluated against quality criteria.

RESULTS

While there was a high degree of heterogeneity across studies, including the methodological quality, there was evidence for some features of the neuropsychological syndrome in children with AgCC. Vulnerabilities in executive function and social cognition were found, with particular difficulties on complex and novel tasks.

INTERPRETATION

Data on the neuropsychological outcomes in children with AgCC are limited. Broad assessments are necessary to determine the extent to which core features of the neuropsychological syndrome may characterize children with AgCC and how additional neuroanatomical features contribute to outcome.

Long-term follow-up in a cohort of children with isolated corpus callosum agenesis at fetal MRI

Objective

This long‐term retrospective follow‐up study aimed to address the knowledge gap between prenatal diagnosis of complete isolated Agenesis of Corpus Callosum (cACC) at fetal MRI and postnatal neurodevelopmental outcome to improve prenatal counseling for parents.

Methods

Data on fetuses with isolated cACC from a single‐center MRI database built up in two decades were considered. Detailed postnatal clinical, neuropsychological evaluations were performed and descriptions of available neuroradiological and genetic data were provided.

Results

Following a detailed neuropsychological evaluation and a long‐term follow‐up, the subsequent results emerged: 38 school‐aged children (older than 6 years) of 50 (aged 2.5‐15 years) showed normal intellectual functions (50%), intellectual disability (21%), and borderline intelligence quotient (29%). Deficits in motor functions (58%), executive functions (37%), language (61%), memory abilities (58%), and academic performances (53%) were found. Twenty‐one percent of participants showed behavioral difficulties. Almost half of the participants underwent rehabilitation. Additional findings (21%) were detected at postnatal brain MRI, and a significant association between additional findings at postnatal imaging and abnormal neurodevelopmental outcome was observed.

Interpretations

This study supports the view that children with prenatal diagnosis of isolated cACC may present with several degrees of neurologic and neuropsychological impairment which become more evident only in their second decade of life. Postnatal MRI and detailed genetic analysis may add crucial information to prenatal data and substantially influence final judgment on the outcome and orient clinical management and counseling.

Heterogeneity in defining fetal corpus callosal pathology: systematic review

OBJECTIVE

Fetal anomalies of the corpus callosum (CC) have been reported in the prenatal imaging literature since 1985, and, especially when isolated, pose challenges for both the patient and fetal medicine specialist. The purpose of this study was to review systematically the literature on prenatally diagnosed abnormalities of the CC, focusing on the terminology used to describe abnormalities other than complete agenesis of the CC, and to assess the heterogeneity of the nomenclature and definitions used.

METHODS

This study was conducted in accordance with the PRISMA statement for reporting systematic reviews. A literature search was performed to identify prospective or retrospective case series or cohort studies, published in English, French, Italian, German or Spanish, reporting fetal imaging findings and describing anomalies of the CC. Quality and risk of bias of the studies were evaluated using the Newcastle-Ottawa scale and a modification of the scale developed by Conde-Agudelo et al. for other fetal imaging studies. The data extracted included the number of patients, the number of different anomalies identified, the descriptive names of the anomalies, and, where applicable, the definitions of the anomalies, the number of cases of each type of anomaly and the biometric charts used. Secondary tests used to confirm the diagnosis, as well as the postnatal or post-termination tests used to ascertain the diagnosis, were also recorded.

RESULTS

The search identified 998 records, and, after review of titles and abstracts and full review of 45 papers, 27 studies were included initially in the review, of which 24 were included in the final analysis. These 24 studies had a broad range of quality and risk of bias and represented 1135 cases of CC anomalies, of which 49% were complete agenesis and the remainder were described using the term partial agenesis or nine other terms, of which five had more than one definition.

CONCLUSIONS

In comparison to the postnatal literature, in the prenatal literature there is much greater heterogeneity in the nomenclature and definition of CC anomalies other than complete agenesis. This heterogeneity and lack of standard definitions in the prenatal literature make it difficult to develop large multicenter pooled cohorts of patients who can be followed in order to develop a better understanding of the genetic associations and neurodevelopmental and psychological outcomes of patients with CC anomalies. As this information is important to improve counseling of these patients, a good first step towards this goal would be to develop a simpler categorization of prenatal CC anomalies that matches better the postnatal literature. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Neurodevelopmental Outcomes following Prenatal Diagnosis of Isolated Corpus Callosum Agenesis: A Systematic Review

Abnormalities of corpus callosum are one of the most common brain anomalies. Fetuses with isolated corpus callosum agenesis (CCA) have a better prognosis than those with additional anomalies. However, unpredictable neurodevelopmental outcomes of truly isolated CCA make prenatal counseling a challenge. The aim of this review is to evaluate neurodevelopmental outcomes in children with prenatal diagnosis of isolated CCA. Controlled clinical trials published between May 23, 2009, and May 23, 2019, using the MeSH term "agenesis of corpus callosum" were reviewed. A total of 942 articles were identified, and 8 studies were included in the systematic review depending on the inclusion criteria. These studies included 217 fetuses with isolated CCA and no other anomalies at prenatal assessment. Neurodevelopmental outcome was reported to be normal in 83 children with a prenatal diagnosis of isolated CCA confirmed at birth within 128 completed assessments. About 45 children presented borderline, moderate, or severe neurodevelopmental outcome. In this review, neurodevelopment was favorable in two-thirds of the cases, but mild disabilities emerged in older children. Despite this, disabilities can occur later beyond school age and a low risk of severe cognitive impairment exists. Our study highlights the essential early diagnosis and proper supportive therapy.

Scoping Review of the Prenatal Diagnosis of Agenesis of the Corpus Callosum

OBJECTIVE

To map and summarize the literature related to the prenatal diagnosis of agenesis of the corpus callosum (ACC) to inform nursing practice.

DATA SOURCES

We searched MEDLINE, CINAHL, PyscINFO, and Academic Search Complete with the use of strings of curated terms to cover the broad ACC nomenclature. Documents were published in English between 2009 and June 1, 2020. We also hand searched the reference lists of included documents.

STUDY SELECTION

We screened 582 abstracts and retrieved the full texts of primary research articles, reviews, discussion papers, and peer-reviewed book chapters if the abstracts specifically mentioned ACC and the prenatal period. We excluded case reports, conference and poster abstracts, papers on broader anomalies, and animal studies. We reviewed 84 full-text documents and identified 61 for inclusion.

DATA EXTRACTION

We charted the data through an iterative process under headings for location, article type, study design, participant age, ACC type, recruitment, method, tools/assessments, results, key recommendations, gestational age at diagnosis, termination of pregnancy rate, the definition of isolated ACC, and our notes of critique of the document.

DATA SYNTHESIS

We constructed a narrative synthesis from thematically arranged data. In the included documents, ACC was diagnosed between 17 and 38 weeks gestation and was frequently described as heterogeneous because of different causes, presentations, and outcomes. Whether the ACC was isolated as the only anomaly or present with other anomalies was considered the key factor for prenatal counseling. However, the definition of isolated ACC was inconsistent.

CONCLUSION

The inconsistent nomenclature and definitions of an isolated presentation of ACC increase the ambiguity in the prenatal diagnosis and must be considered when the outcome and diagnostic efficacy studies are interpreted. There is an absence of research on parents' experiences of prenatal diagnoses of ACC to inform holistic nursing interventions and the provision of psychosocial support.

Utilization of neurosonography for evaluation of the corpus callosum malformations in the era of fetal magnetic resonance imaging

AIM

We evaluated the ability of fetal neurosonography and magnetic resonance imaging (MRI) to asses callosal anomalies (CA) and associated cranial malformations. We also aimed to determine the long-term prognosis of the cases.

METHODS

Thirty-six cases of CA diagnosed combined with neurosonography and MRI between January 2012 and October 2017 were retrospectively reviewed.

RESULTS

Seventeen of 36 fetuses were diagnosed complete agenesis of corpus callosum (CACC) (47.2%), 9 had partial agenesis of corpus callosum (PACC) (25%) and 10 was dysgenesis of the corpus callosum (DCC) (27.2%) at ultrasonography (US) examination. Fetal MRI reported 16 of cases as CACC (44.4%), 11 PACC (30.5%) and nine (25%) DCC. The overall consistency between neurosonography and MRI in the definition of CA were 91% of cases. Sulcation anomalies were present in 9 cases in the US (25%) and 11 cases in MRI (30.4%). Seven of cases showed posterior fossa abnormalities in the US (19.4%) and eight cases in MRI (22.1%). Neonatal MRI added new findings to fetal MRI and neurosonography including grade-1 intraventricular hemorrhage and periventricular leukomalacia in two cases (12.5%). Eighteen cases were terminated (50%), 17 cases were followed up and mean follow up interval was 39 ± 5.1 months. The neurologic outcome was abnormal in seven (41.7%) patients. Presence of associated brain anomalies worsened the prognosis.

CONCLUSION

Fetal neurosonography has a comparable performance with MRI in the diagnosis of CA and associated anomalies. It should be used in collaboration with MRI to achieve accurate diagnosis which is crucial for counseling.

Diagnostic value of Omniview technique on the agenesis of corpus callosum

Objective: This study aimed to discuss the diagnostic value of Omniview technique on the agenesis of corpus callosum. Methods: A total of 43 pregnant women with no obvious structural abnormality and eight pregnant women who diagnosed with agenesis of corpus callosum (ACC) were included in this study. The 2D ultrasonography and the 3D ultrasonography Omniview technique were used to carry out ultrasonic examination on 43 normal fetuses and eight fetuses with agenesis of corpus callosum (as verified through magnetic resonance), respectively. Results: The Omniview technique visually displayed the median sagittal plane of the fetus. The ROC curve of Omniview (0.999) was much higher than that of 2D ultrasonography (0.817). Rating of ACC and normal fetuses showed that the diagnostic efficiency of 3D ultrasonography Omniview technique was much higher than 2D ultrasonography. Conclusion: 3D ultrasonography Omniview technique has certain advantage in the diagnosis of agenesis of corpus callosum, and is of great significance in the prenatal screening of callosum.

Outcome of isolated agenesis of the corpus callosum: A population-based prospective study

OBJECTIVES

Neurodevelopmental outcome of apparently isolated agenesis of the corpus callosum (ACC) remains a major concern with uncertain prognosis. Despite "normal" IQ reported in a majority of patients, the rates of learning disabilities and severe outcome (ranging from 0% to 20%) are not clearly established.

METHODS

A large population-based series was investigated based on a longitudinal follow-up until school age, using Wechsler Intelligence scales at 3, 5, and 7 years.

RESULTS

Fifty women were referred to a tertiary referral unit for an "apparently" isolated ACC confirmed by ultrasound, foetal MRI, and karyotyping or array CGH. Twelve pregnancies were terminated, one foetus died in utero, one pregnancy outcome was unknown, and 36 babies were born. Two were lost to follow-up. Thirty-four children could be classified into three groups. Group 1 comprised two children (6%) with severe intellectual disability (one Mowat-Wilson syndrome and one ASD). Group 2 comprised 10 children (29%) who had learning disabilities and borderline intellectual functioning (VIQ and/or PIQ scores >70 and <85); three patients had hypopituitarism with additional MRI anomalies revealed after birth. Group 3 comprised 22 children (65%) who had both VIQ and PIQ >85 (-1 SD) with a normal school level. Longitudinal follow-up revealed weaker PIQ in younger children which improved with age.

CONCLUSION

Our data indicate that intellectual ability is normal (IQ > 85) in approximately two thirds and borderline in just over a quarter of patients. However, a low risk of severe cognitive impairment exists, and this information should be shared with couples during prenatal counselling.

Clinical outcomes and neurodevelopmental outcome of prenatally diagnosed agenesis of corpus callosum in single center of Korea

OBJECTIVE

With recent advances and frequent use of prenatal ultrasound, the antenatal diagnosis of agenesis of the corpus callosum (ACC) is not rare in obstetrics practices. However, information regarding the long-term neurological outcome remains uncertain. The aim of this study was to investigate clinical outcomes of prenatally diagnosed ACC and to analyze postnatal neurodevelopmental outcomes of ACC neonates born in our single center.

METHODS

We retrospectively reviewed 56 cases of prenatally suspected ACC referred to our center.

RESULTS

Fifty-six fetuses were diagnosed with ACC, and 12 of those were followed-up in our center until delivery. Of the remaining 44, 7 were delivered after being referred back to the original hospital, 23 were lost to follow-up, and 14 had unknown outcomes. Among all 56, 29 were considered to have isolated ACC and 27 were considered to have non-isolated ACC. Of the 10 live fetuses delivered in our center, four had isolated ACC, three had non-isolated ACC, and the rest had outcomes unrelated to ACC. Neurodevelopmental outcome was followed-up until approximately age 3 years. Of the four with isolated ACC, three (75%) had normal neurodevelopmental outcomes.

CONCLUSION

Similar to other studies, the results of our single-center study included positive neurodevelopmental outcomes for those with isolated ACC. However, despite our endeavor to counsel patients with prenatally diagnosed ACC, the delivery rate in our center was quite low. Therefore, larger, multicenter, retrospective studies including long-term neurological development outcomes are crucial and urgently needed to provide better counseling.

Outcomes Associated With Isolated Agenesis of the Corpus Callosum: A Meta-analysis

CONTEXT

Antenatal counseling in cases of agenesis of the corpus callosum (ACC) is challenging.

OBJECTIVES

To ascertain the outcome in fetuses with isolated complete ACC and partial ACC.

DATA SOURCES

Medline, Embase, CINAHL, and Cochrane databases.

STUDY SELECTION

Studies reporting a prenatal diagnosis of ACC. The outcomes observed were: chromosomal abnormalities at standard karyotype and chromosomal microarray (CMA) analysis, additional anomalies detected only at prenatal MRI and at postnatal imaging or clinical evaluation, concordance between prenatal and postnatal diagnosis and neurodevelopmental outcome.

DATA EXTRACTION

Meta-analyses of proportions were used to combine data.

RESULTS

Twenty-seven studies were included. In cACC, chromosomal anomalies occurred in 4.81% (95% confidence interval [CI], 2.2-8.4) of the cases. Gross and fine motor control were abnormal in 4.40% (95% CI, 0.6-11.3) and 10.98% (95% CI, 4.1-20.6) of the cases, respectively, whereas 6.80% (95% CI, 1.7-14.9) presented with epilepsy. Abnormal cognitive status occurred in 15.16% (95% CI, 6.9-25.9) of cases. In partial ACC, the rate of chromosomal anomalies was 7.45% (95% CI, 2.0-15.9). Fine motor control was affected in 11.74% (95% CI, 0.9-32.1) of the cases, and 16.11% (95% CI, 2.5-38.2) presented with epilepsy. Cognitive status was affected in 17.25% (95% CI, 3.0-39.7) of cases.

LIMITATIONS

Different neurodevelopmental tools and time of follow-up of the included studies.

CONCLUSIONS

Children wih a prenatal diagnosis of isolated ACC show several degrees of impairment in motor control, coordination, language, and cognitive status. However, in view of the large heterogeneity in outcomes measures, time at follow-up, and neurodevelopmental tools used, large prospective studies are needed to ascertain the actual occurrence of neuropsychological morbidity of children with isolated ACC.

What Is the Rate of Incomplete Fetal Anatomic Surveys During a Second-Trimester Scan? Retrospective Observational Study of 4000 Nonobese Pregnant Women

OBJECTIVES

The purpose of this study was to estimate the rate of incomplete fetal anatomic surveys during a second-trimester scan due to an unfavorable fetal position in a nonobese population.

METHODS

All pregnant women who came to the Altamedica Fetal-Maternal Medical Center, a specialized center for prenatal diagnosis, for a routine second-trimester scan between January 2012 and April 2013 were retrospectively included in the analysis. Patients with a body mass index higher than 30.0 kg/m(2) or anterior fibroids larger than 5 cm were not included in the study.

RESULTS

Of 4000 pregnant women admitted for a second-trimester scan, 169 (4.2%) came back within 2 weeks to complete the examination because of an unfavorable fetal position. In particular, 104 (2.6%) needed visualization of only 1 view, and 65 (1.6%) needed more than 1 view. The most difficult organ to visualize was the corpus callosum, in 73 cases (1.8%); the face was not visualized in 69 cases (1.7%); the cerebellar vermis was not seen in 47 fetuses (1.1%); and the heart could not be completely examined in 40 fetuses (1.0%). Of the 4000 women, 169 (4.2%) had a nonexhaustive scan; 149 (3.7%) needed a second scan to complete the second-trimester survey; 14 (0.35%) needed a third scan; and 2 (0.05%) remained with a not completely exhaustive scan.

CONCLUSIONS

There is always a small percentage of incomplete fetal anatomic surveys during a second-trimester scan, which cannot be modified by the sonographer's skill or by technical sonographic innovations.

Antenatal diagnosis of agenesis of the corpus callosum

AIM

To estimate the diagnostic performance of ultrasound in detecting agenesis of the corpus callosum (ACC).

MATERIALS AND METHODS

A retrospective review was performed of 1722 in utero MRI examinations. All cases were identified in which the fetus had been referred from ultrasonography with a diagnosis of ACC and those in which ACC was given as a diagnosis on the in utero MRI study. The MRI was assumed to provide the correct diagnosis of ACC and descriptive statistics of diagnostic accuracy for ultrasound were calculated.

RESULTS

Of the 1722 ultrasound examinations performed, 121 had a diagnosis of ACC and approximately 50% were confirmed at MRI. Forty-two fetuses with ACC not suspected at ultrasonography were also identified at MRI. Ultrasonography had a positive predictive value of 47% (95% CI: 38-56%) and a negative predictive value of 97% (95% CI: 96-98%) for detecting ACC.

CONCLUSION

Ultrasound is poor in diagnosing ACC and in utero MRI should be performed if there is any suspicion on antenatal ultrasonography.

Reference charts for fetal corpus callosum length: a prospective cross-sectional study of 2950 fetuses

OBJECTIVES

The purpose of this study was to establish reference charts for fetal corpus callosum length in a convenience sample.

METHODS

A prospective cross-sectional study was conducted at the Artemisia Fetal-Maternal Medical Center between December 2008 and January 2012. Among 16,975 fetal biometric measurements between 19 weeks and 37 weeks 6 days' gestation, 3438 measurements of the corpus callosum (20.3%) were available. After excluding 488 measurements (14.2%), a total of 2950 fetuses (85.8%) were considered and analyzed only once. Parametric and nonparametric quantile regression models were used for the statistical analysis. To evaluate the robustness of the proposed reference charts with respect to various distributional assumptions on the sonographic measurements at hand, we compared the gestational age (GA)-specific reference curves produced by the statistical methods used.

RESULTS

The mean corpus callosum length was 26.18 mm (SD, 4.5 mm; 95% confidence interval, 26.01-26.34 mm). The linear regression equation expressing the length of the corpus callosum as a function of GA was length (mm) = -11.17 + 1.62 × GA. The correlation between the dimension and gestation was expressed by the coefficient r = 0.83. Normal mean lengths according the parametric and nonparametric methods were defined for each week of gestation.

CONCLUSIONS

This work provides new quantile-based reference charts for corpus callosum length measurements that may be useful for diagnosis of congenital corpus callosum anomalies in fetal life.

Agenesis of the corpus callosum: classifying functional manifestations with the ICF-CY

PURPOSE

Agenesis of the corpus callosum (ACC) is a congenital condition in which the corpus callosum fails to develop fully. In the literature, ACC has been broadly conceptualized and inconsistently described. This article demonstrates how the universal language of the International Classification of Functioning, Disability and Health-Children and Youth can increase the specificity with which researchers and clinicians describe the variable manifestations of ACC.

METHODS

The database for this article was based on a review of 83 studies on developmental and neuropsychological manifestations of congenital ACC in children and adolescents. First, the extent to which the findings on ACC could be documented using the taxonomic codes in the ICF-CY was examined. Next, the findings from each study were mapped onto the ICF-CY to summarize the distribution of clinical features reported in the literature.

RESULTS

There was a high degree of correspondence between the reported findings and the taxonomic codes of the ICF-CY. The distribution of clinical features was discussed.

CONCLUSIONS

This taxonomic application advances the ICF-CY as a common language for researchers and clinicians who work with children who have ACC. Implications for Rehabilitation Agenesis of the corpus callosum (ACC) is a condition that has been broadly conceptualized and inconsistently described in research and practice. The variable clinical manifestations of children with ACC can be most effectively described using the ICF-CY. The application of the ICF-CY to conditions with highly variable clinical manifestations, like ACC, positively impacts research and practice.

Counseling in fetal medicine: agenesis of the corpus callosum

In this Review, we aim to provide up-to-date and evidence-based answers to common questions regarding the diagnosis and prognosis of prenatally detected agenesis of the corpus callosum (ACC). A systematic literature search was performed to identify all reports of ACC and reference lists of articles were identified. ACC involves partial or complete absence of the main commissural pathway that connects the two cerebral hemispheres, and can be isolated (with no other abnormalities) or complex (coexisting with other abnormalities). It is a rare finding and the prevalence is difficult to estimate because of selection bias in reported series. The corpus callosum (CC) can be assessed on ultrasound by direct visualization, but indirect features, such as ventriculomegaly, absence of the cavum septi pellucidi or widening of interhemispheric fissure, are often the reason for detection in a screening population. Careful imaging in a center with a high level of expertise is required to make a full assessment and to exclude coexisting abnormalities, which occur in about 46% of fetuses. When available, magnetic resonance imaging appears to be an important adjunct as it allows direct visualization. It can reduce false-positive rates on ultrasound and can confirm ACC, it can assess whether this is complete or partial and it can help in detecting coexisting brain abnormalities not seen on ultrasound. The overall rate of chromosomal abnormality in fetuses with ACC is 18%, but this high rate includes both isolated and complex ACC; more recent studies suggest that chromosomal abnormalities are rare in isolated cases. Nevertheless, postnatal follow-up studies suggest that about 15% of cases thought to be isolated prenatally were found to have associated abnormalities after birth. Neurodevelopmental outcome in isolated ACC was recently reported in a systematic review and suggested normal outcome in about 65-75% of cases. Findings need to be considered in light of the several limitations of existing studies, in terms of study design, selection bias, varying definitions and imaging protocols, ascertainment bias and lack of control groups. These uncertainties mean that antenatal counseling is difficult and further large prospective studies are needed.

Neurodevelopment after prenatal diagnosis of isolated agenesis of the corpus callosum: an integrative review

OBJECTIVE

To systematically review published data on the neurodevelopment of children that were diagnosed prenatally with isolated agenesis of the corpus callosum.

STUDY DESIGN

Medline and Scopus searches (1960-July 2011); cross-referencing of retrieved articles.

RESULTS

Sixteen reports (132 cases of apparently isolated agenesis of the corpus callosum) were included in the analysis. The rates of normal outcome, borderline or moderate disability and severe disability were 94/132 (71.2%; 95% confidence interval [CI], 63.0-78.3), 18/132 (13.6%; 95% CI, 8.8-20.5), and 22/132 (15.2%; 95% CI, 10.0-22.2), respectively. Magnetic resonance imaging detected additional cerebral abnormalities in 22.5% (95% CI, 12.3-37.5) of apparently isolated agenesis of the corpus callosum cases. In truly isolated agenesis of the corpus callosum (confirmed by magnetic resonance imaging), the rates of normal neurodevelopment and severe disability were 52/69 (75.4%; 95% CI, 64.0-84.0) and 8/69 (11.6%; 95% CI, 6.0-21.2), respectively.

CONCLUSION

Prenatally diagnosed, isolated agenesis of the corpus callosum is usually associated with a favorable outcome. Larger, prospective series are required, as current data are limited, inconsistent, and prevent subgroup analyses (eg, complete vs partial agenesis of the corpus callosum).