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Corpus callosum disorders and associated malformations in paediatric epilepsy: MRI analytic study



To assess the effectiveness of MRI in identifying the spectrum of corpus callosum anomalies in epileptic paediatric patients, a descriptive case series was studied in the General Paediatric Hospital, Baghdad from March 2017 to March 2020.A total of 52 patients with ages ranging from 4 months to 14 years were included. The Imaging criteria included MRI evaluation showing spectrum of anomalies involving the corpus callosum with malformation of cortical development, lipoma, Dandy Walker syndrome and Chiari malformation. Demographic data was recorded. The study included 52 patients with ages ranging from 4 months to 14 years, (mean age 5.94 ± 4.08 years). There were 31(59.7 %) males and 21(40.3%) females diagnosed as 34(65%) agenesis, 25(48%) partial agenesis, 9(17.3%) complete agenesis and 18(34.7%) hypoplasia of corpus callosum. Other malformations noted in 32 patients included, Chiari malformation, cortical neuromigration disorders, Dandy Walker malformation, lipoma, cerebellar hypoplasia, posterior fossa arachnoid cyst and Chiari 2 malformation. Imaging evaluation in epilepsies, effectively detects callosal disorders and associated malformations, which add valuable data improving clinical management, seizure control clinical management and further decision-making.
To assess the effectiveness of MRI in identifying the
spectrum of corpus callosum anomalies in epileptic
paediatric patients, a descriptive case series was studied in
the General Paediatric Hospital, Baghdad from March 2017
to March 2020.A total of 52 patients with ages ranging from
4 months to 14 years were included. The Imaging criteria
included MRI evaluation showing spectrum of anomalies
involving the corpus callosum with malformation of cortical
development, lipoma, Dandy Walker syndrome and Chiari
malformation. Demographic data was recorded. The study
included 52 patients with ages ranging from 4 months to 14
years, (mean age 5.94 ± 4.08 years). There were 31(59.7 %)
males and 21(40.3%) females diagnosed as 34(65%)
agenesis, 25(48%) partial agenesis, 9(17.3%) complete
agenesis and 18(34.7%) hypoplasia of corpus callosum.
Other malformations noted in 32 patients included, Chiari
malformation, cortical neuromigration disorders, Dandy
Walker malformation, lipoma, cerebellar hypoplasia,
posterior fossa arachnoid cyst and Chiari 2 malformation.
Imaging evaluation in epilepsies, effectively detects callosal
disorders and associated malformations, which add
valuable data improving clinical management, seizure
control clinical management and further decision-making.
Keywords: corpus callosum, anomalies, epilepsy, MRI
The corpus callosum (CC) is a midline cerebral white matter
structure, which represents the largest forebrain
commissure of tightly packed tracts in the central nervous
system, connecting the two cerebral hemispheres. It
comprises of four parts, rostrum, genu, body and splenium.
It is formed from anterior to posterior, beginning with the
genu at 12th weeks gestation. The rostrum is an exception,
as it develops last at 18-20 weeks.1-3 If the Corpus callosum
does not form prior to birth, it will never form. If there are
some corpus callosum nerves crossing between the
hemispheres at birth, these may continue to develop, but
new nerves or fibers will not develop. Since agenesis of CC
is congenital, all the rest of the brain connections are
organized accordingly.4 Congenital callosal malformations
range from agenesis, hypogenesis or hypoplasia (complete
CC but thin). The Callosal hypogenesis (partial absence) is
associated with other cerebral malformations, such as
migration disorders, Dandy Walker etc.5,6 Abnormal
imaging findings can be seen in a person with epilepsy.5
Thus neuroimaging has an important application in the
diagnosis and treatment. Computed tomography,
combined with EEG recording which has an essential role in
confirming the clinical diagnosis, represent the standard
clinical practice for a child with recurrent seizures.7,8
Computed tomography is important for the diagnosis of
CC lipoma, and other acquired pathologies with
calcifications or haematomas' involving the anterior part.9
Agenesis of the corpus callosum is one of the most
frequent malformations in the brain with a reported
incidence ranging between 0.5 to 70 in 10000.10 Disorders
of the CC may be caused by arrested growth, or delayed
development that attempts to compensate for earlier
abnormalities in the evolution of midline structures. It can
also be observed in association with major malformations
of the embryonic forebrain prior to formation of the anlage
of the corpus callosum e.g., holoprosencephaly.2,11
Currently, MRI which is safe and painless, is the imaging
procedure of choice in infants and children. It is
recommended in the evaluation of cerebral pathologies
and is used in evaluating agenesis of CC, even in patients
who have previously undergone CT scan and ultra-
sonography examination. The Multiplanner capability and,
high soft tissue contrast permits confident diagnosis of
agenesis of corpus callosum and its associated anomalies
especially neuronal migration anomalies or atypical form of
holoprosencephaly.12-14 Magnetic resonance Imaging
defines CNS anatomy in detail, permits in-vivo
characterization of human brain anomalies, previously
incompletely evaluated using CT scan and
ultrasonography. Certain anomalies, previously thought to
be isolated, have proven to be associated with one or more
brain malformations. Thus, MRI sheds new light on a
fundamental problem in clinical neuroradiology.15 Corpus
callosum and other interhemispheric connections are
considered to transfer unilateral abnormal electrical
activities to the contra lateral hemisphere.
Vol. 71, No. 12 (Suppl. 8), December 2021
S-190 15th Annual Conference of the College of Medicine, Mustansiriyah University, Baghdad
Department of Pediatrics, College of Medicine, Mustansiriyah University,
Baghdad, Iraq.
Correspondence: Email:
Corpus callosum disorders and associated malformations in paediatric epilepsy:
MRI analytic study
Muna Abdul Ghani Zghair
Magnetic resonance imaging mapping, confirms the
genu of corpus callosum, as the major pathway for
seizures generalization.16 This study aimed to verify the
role of MRI in the diagnosis of callosal disorders among
epileptic patients in the paediatric age group.
A descriptive case series on 52 patients was conducted in
the radiology department MRI unit, of a major tertiary
paediatric health care center (Central Teaching Hospital of
Paediatrics'), Baghdad, Iraq, from March 2015 to April 2020.
It was an observational study including 52 patients. The
Ethical Committee of the Medical College and Central
Teaching Hospital of Paediatrics approved the study.
Included were 31 males and 21 females with age ranging
from 4 months to 14 years. The decision to perform MRI
was based on the clinical judgment of the referring
paediatric neurologist. All patients included had history of
seizures. Demographic criteria collected were age and
gender, Imaging of corpus callosum with associated
disorders, types, severity and malformations.
Measurements were taken at the mid sagittal plain view
which clearly defined the four callosal components,
rostrum, genu, body, and splenium. Axial plain showed
parallel configuration of the lateral ventricles, coronal
plains showed midline defects associated with Lipoma, and
listhencephaly. Patients were divided according to age (4
months -1 year), (2-5 years) and (6- 14 years). Imaging
criteria were based on the identification of complete ACC,
partial ACC, hypogenesis, and associated malformations of
cortical development, ventricles, posterior fossa and extra-
axial spaces. This was a native study without intravenous
contrast media as the contrast does not provide a further
diagnostic value. Utilizing MRI machine with 1.5 Tesla
MEGNATOM Avanto scanner (Siemens, Germany) was
employed. Using head coil, with T1, T2, FLAIR and diffusion
weighted sequences, with the required plains, sagittal, axial
and coronal plains, the corpus callosum appeared as high
signal on T1, low signal in T2 and intermediate signal on
FLAIR sequences. The duration of each examination lasted
about 20 minutes. General anaesthesia was recommended
for children under 6 years age and in the older non-
cooperative or nervous children. In older children, the
examination was explained to both the patient and
relatives, to relieve anxiety. Our centre permits the stay of
parents in the MRI examination room throughout the test.
The exclusion criteria were, patients with history of
preterm delivery, infectious, ischaemic, haemorrhagic,
traumatic, tumoural, iatrogenic and toxic cerebral
pathologies. The Center's traditional workup excluded
neonates and infants less than 4 months' age to avoid the
vulnerable potential hazards of electromagnetic field
effect, physiological instability and sedation. Patients with
inadequate scan quality were also excluded. In these
patients, Computed tomography replaced MRI.
Data were collected, summarized, analyzed and presented
using Statistical package of Microsoft office Excel 2010.
The results of data analysis was presented as mean with
standard deviation and ranges to determine the number
and percentages (%) per hundred using one sample with a
descriptive, quantitative, observational and exploratory
analysis design.
The study group comprised of 52 paediatric patients, of
various callosal disorders and associated anomalies. The
age range of the children was from 4 months to 14 years,
with a mean age of 5.94 ± 4.08 years. All patients selected
had a history of full term delivery. These results are
summarized in Table-1. Magnetic resonance imaging
findings of corpus callosum disorders showed, complete
agenesis, partial agenesis and hypoplasia representing
9(17.3%), 25(48%) and 18(34%) cases respectively.
Associated malformations contributed to 32(62%) cases.
Hypoplastic extra colossal and supra tentorial white
J Pak Med Assoc (Suppl. 8)
15th Annual Conference of the College of Medicine, Mustansiriyah University, Baghdad S-191
Figure-1: Associated congenital anomalies.
matter was a constant observation in the entire study
group. Pachygyra and Dandy Walker syndrome were the
more frequent associated malformations, being 10 (19.2%)
and 6 (11.2%) respectively. There was non-specific age or
gender distribution of isolated callosal disorders. About
one-half of female patients presented with imaging
features of both callosal disorders and malformation.
Seventy percent of epileptic male patients had callosal
disorders and additional malformations. Table-1 shows
the maximum age distribution in the category of 2-5
years. Male gender was more effected, 31 (59.7 %) with
partial agenesis in 25 (48%).
Figure-1 displays the associated malformations, with
Pachygyra (30.1 %) being more frequent.
Figure-2 displays the mid sagittal FLAIR sequence
showing complete absence of corpus callosum with
Pachygyra, involving frontal parietal and occipital lobes.
Agenesis of the corpus callosum is an abnormal
developmental malformation involving the white matter
commissural fibers. It represents the largest intra cerebral
connecting white matter bands, between the two
hemispheres of the cerebrum. Callosal disorder
involvement could be in various forms, complete absence
(agenesis), partial agenesis, when the missing component
involves one of the portions, genu, body, splenium or the
rostrum or is hypo-plastic, when corpus callosum is
present without a missing segment but thin or smaller
than normal. These abnormalities are diagnosed by
various neuro-imaging modalities, Ultrasonography, CT
scan and MRI. MRI is the imaging investigation of choice
in these circumstances. It utilizes a non-ionizing radiation
device, providing an excellent intrinsic soft tissue contrast
discrimination with Multiplanner facilities along with
providing more comprehensive, additional information
which aids in the diagnosis. Nevertheless, it is time
consuming with most paediatric patients requiring
sedation or general anaesthesia. The specific selection of
paediatric patients presenting with epilepsy in the current
study was observed as it is the most common clinical
association with corpus callosum disorders. In the clinical
description of Marie-Laure Moutard, the author describes
epilepsy in 50 % of patients presenting with agenesis of
corpus callosum.17 Neonatal and prenatal imaging studies
suggest that corpus callosum agenesis occurs in at least
1:4000 live births.18 Abnormalities of corpus callosum was
almost always accompanied by other brain
malformations and grey matter heterotopia was the most
common malformation of cortical development.15 In the
current series, 32 of the 52 patients presented with
associated brain malformations. This makes a figure of
61.6%. The types of individual, accompanied
malformations in our study differ with Dandy Walker
syndrome, and pachygyra being the most common
malformations. Interhemispheric cysts and lipoma were
present in 15 patients. In this study, we also found two
patients with lipoma and one patient with listhencephaly.
The difference in data observation between our study and
others,15,17 is related to the inclusion of variable clinical
CNS and somatic manifestations in multicentre studies.
This will offer a large sample size and more generalizable
MRI findings. Enrolling asymptomatic individuals with
callosal disorders, with a wider age range, based on
retrospective data collection from the database network
can raise a doubt on the frequency of the corpus callosum
disorders. This study describes the MRI findings of a single
tertiary centre on selected symptomatic paediatric
Vol. 71, No. 12 (Suppl. 8), December 2021
S-192 15th Annual Conference of the College of Medicine, Mustansiriyah University, Baghdad
Table-1: Findings of MRI in corpus callosum defects in relation to age and gender.
Variable No. %
Age (years) 0-2 13 25
2-5 18 34.6
5-10 11 21.2
10-15 10 19.2
Gender Female 21 40.3
Male 31 59.7
Types of Corpus Collosum Defect Agenesis 9 17.3
Partial 25 48
Hypoplastic 18 34.7
Associated Anomalies Multiple anomalies 12
single anomaly 20 32 62
Figure-2: a) T1-weighted Spin echo sagittal plane MRI. Total absence of corpus callosum,
cerebellar hypoplasia, frontotemporal Pachygyra and Semi lobar holoprosencephaly. b)
Bilateral semi lobar holoprosencephaly and cerebellar hypoplasia.
patients who presented with epilepsy, with a limited age
range showing MRI imaging criteria pointing to
congenital anomalies. This represents a superior inclusion
criterion. The other factor is the choice of a single centre
work up approach, might increase the risk of bias which
can modify the results. However, child epilepsy is a critical
care emergency situation. A single centre study provides
more effective treatment estimates, with a closer follow
up observation than a multicentre trial. Extra-callosal,
supra-tentorial reduced white matter volume was a
constant observation in all cases included in our study.
This is in agreement with other studies, as the corpus
callosum is the principle transverse white matter tract
connecting the cerebral hemispheres.15 In the current
series, agenesis and hypoplastic corpus callosum is more
in boys than girls which is a similar observation in the
literature.12,19 Imaging MRI observation of Partial callosal
agenesis is the most common feature, followed by
callosal hypoplasia and complete agenesis. This is in
accordance with the studies published by Barkovich
and Essam et al.1,20
Magnetic resonance imaging is a unique neuro-
radiological imaging technique in confirming the
detection of corpus callosum disorders, midline structures
and associated malformations. The standard mid sagittal
and coronal sectional plains, confidently provide a high
diagnostic performance, which allows, correct diagnosis,
decision making and subsequent management.
Acknowledgement: The help by Dr. Ahlam Mohamad
Albojassim, C.A.B.P/ pediatrics is gratefully
Disclaimer: None.
Conflicts of Interest: None.
Source of Support: Al Mustansiriryah University College
of Medicine, Baghdad, Iraq.
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... computed tomography (CT) and magnetic resonance imaging (MRI) are common neuroimaging means, and CT that shows more significant advantages have been gradually applied in the clinical diagnosis and treatment of various brain tissue lesions. [6][7][8] This paper analyzed the characteristics of vascular dementia induced by ischemic stroke and the advantages of using cranial MRI for early diagnosis and treatment, with the aim of providing a reference for early diagnosis and treatment of this disease and providing clinical lessons. ...
Objective: This study aimed to observe the diagnostic value of cranial magnetic resonance imaging (MRI) in patients with vascular dementia induced by ischemic stroke. Methods: The experiment was designed according to the randomized control principle. Two hundred and eighty patients with ischemic stroke who were admitted to Gucheng County Hospital between June 2019 and June 2021 were selected as research subjects. Patients without vascular dementia after stroke were included in the control group, and patients with vascular dementia after stroke were included in the observation group. The cranial MRI was performed in both groups. Results: Proportions of patients with large and moderate infarct lesions in brain tissues were significantly higher in the observation group than the control group. The data variation of relevant MRI detection indicators of the observation group was more obvious than that of the control group (P<0.05). The mini-mental state examination (MMSE) and Montreal cognitive assessment (MoCA) scores of the observation group were lower than those of the control group (P<0.05), but the HIS score was higher (P>0.05). Patients with changes in brain morphology were more in the observation group than the control group (P<0.05). Conclusion: Patients with vascular dementia induced by ischemic stroke are characterized by cortical atrophy, widening of the cerebral sulcus, large infarct lesion area and sparse cerebral white matter. Cranial MRI can effectively identify these features. The application of cranial MRI has some clinical values for early treatment and prognostic assessment. doi: How to cite this: Zhou W, Li L, Lang Y, Jiang H. Clinical characteristics of cerebral vascular dementia and early diagnostic value of cranial nuclear magnetic resonance. Pak J Med Sci. 2023;39(2):---------. doi: This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Full-text available
To ascertain the incidence and clinical implications of agenesis of the corpus callosum (ACC) in spinal open neural tube defects (SONTD). All cases of SONTD registered at the Spina Bifida Clinic in King Khalid University Hospital, Riyadh, Saudi Arabia between 1995 and 2010 were retrospectively reviewed, and mid-sagittal MRI of the corpus callosum (CC) area was analyzed in each case. Neurodevelopmental outcome was classified as poor in children with seizures, severe neurodevelopmental impairment, or death. Thirty-eight patients (45.8%) with ACC were identified among 83 cases with SONTD. Patients' age ranged between one and 16 years. Total ACC was found in 10 patients, partial ACC in 25, and in 3 patients, the CC was hypoplastic. Active hydrocephalus was an associated finding in 9 out of 10 patients with total ACC, 22 out of 25 with partial ACC, and in all patients with hypoplasia of the CC. Thirteen patients (34.2%) had normal intellectual function, whereas 24 patients presented with learning disability, epilepsy, or poor intellectual function; and one patient died of respiratory failure. Agenesis of the corpus callosum is found in a significant portion of patients with SONTD. When associated with hydrocephalus, its presence affects neuro-developmental outcome.
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Background: Some patients with oligodendrogliomas have generalized tonic-clonic seizures (GTCS) while others have only partial seizures (PS). We investigated the relationship between tumour localization and seizure generalization using quantitative lesion mapping on magnetic resonance images. Methods: Twenty one patients with histologically proven oligodendrogliomas and GTCS (n=11) or PS (n=10) were studied. Data were acquired on a 3 Tesla MRI System. We performed lesion mapping techniques to compare the spatial distribution of oligodendrogliomas between patient groups, and quantitatively determined the extent to which lesions intersected each probabilistic regions-of-interest, including the cerebral lobes, thalamus, striatum, and genu of the corpus callosum. Results: In patients experiencing GTCS, the greatest lesion load was observed in mesial frontal regions, including cortex connected to the genu. In contrast, the greatest lesion load in patients experiencing PS was observed more caudo-laterally in orbitofrontal and temporal lobes, but typically sparing cortex connected to the genu. The number of lesion intersections with genu region of interest was significantly greater in patients experiencing GTCS relative to patients with PS (p=0.03). There were no significant differences between patient groups with respect to lesion intersection with the individual cerebral lobes, thalamus and striatum, or with respect to overall oligodendroglioma size. Conclusion: Our data suggest that the genu of the corpus callosum may be a major pathway for seizure generalization in patients with oligodendrogliomas.
Full-text available
The corpus callosum is a midline cerebral structure and has a unique embryological development pattern. In this article, we describe the pathophysiology and present imaging findings of various typical/atypical conditions affecting the corpus callosum. Since many of these pathologies have characteristic appearances on magnetic resonance imaging (MRI) and their therapeutic approaches are poles apart, ranging from medical to surgical, the neuroradiologist should be well aware of them.
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The corpus callosum is the largest white matter structure in the brain, consisting of 200-250 million contralateral axonal projections and the major commissural pathway connecting the hemispheres of the human brain. The pathology of the corpus callosum includes a wide variety of entities that arise from different causes such as congenital, inflammatory, tumoural, degenerative, infectious, metabolic, traumatic, vascular and toxic agents. The corpus callosum, or a specific part of it, can be affected selectively. Numerous pathologies of the corpus callosum are encountered during CT and MRI. The aim of this study is to facilitate a better understanding and thus treatment of the pathological entities of the corpus callosum by categorising them according to their causes and their manifestations in MR and CT imaging. Familiarity with its anatomy and pathology is important to the radiologist in order to recognise its disease at an early stage and help the clinician establish the optimal therapeutic approach.
Full-text available
There is gathering evidence to suggest that agenesis of the corpus callosum is associated with delayed fetal sulcation; it is possible that the corpus callosum facilitates normal gyral development. In this paper we sought to confirm whether delayed sulcation is found in fetuses with isolated agenesis of the corpus callosum as judged by in utero MR imaging. Retrospective analysis of 20 fetuses with isolated corpus callosum agenesis investigated by in utero MR imaging and 20 aged-matched normal fetuses was performed in the second or third trimester. All fetuses were singleton pregnancies with known gestational age, imaged on a 1.5T superconducting MR system. Estimation of sulcation maturity was made with reference to a standard atlas and subgroup analysis of earlier gestation (group 1, 21-26 weeks) and later gestation (group 2, 30-34 weeks) fetuses was performed. Group 1 (n = 12) did not show a statistically significant difference between the 2 subgroups (P = .44) in terms of sulcation. A significant difference was demonstrated in the later gestation, group 2 (n = 8) fetal analyses; mean difference between consensus and actual gestation for normal fetuses was 0.9 weeks (SD of 1.5 weeks) versus -0.5 weeks (SD of 1.1 weeks) for the agenesis of corpus callosum cases (P = .046), suggestive of delayed sulcation in callosal agenesis. Delayed sulcation encountered in third trimester fetuses with agenesis of the corpus callosum may be seen and does not in itself imply an additional brain abnormality.
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Anomalies associated with callosal agenesis (ACC) found postnatally have been well documented. However, to our knowledge, no detailed MR imaging analysis of associated anomalies has been reported in a large cohort of fetuses with ACC. This study will assess those anomalies and compare them with postnatal cohorts of ACC, to identify associated fetal brain abnormalities that may give insight into etiology and outcome. All cases of ACC diagnosed on fetal MR imaging during an 11-year period were retrospectively reviewed, including fetal MR imaging, postnatal MR imaging, and autopsy findings. Neurodevelopmental outcome was classified as poor in children with seizures and/or severe neurodevelopmental impairment or in cases of neonatal death. Twenty-nine cases of ACC were identified. Median gestational age was 26.14 weeks (range, 19.71-36.43 weeks). Twenty-three fetuses had delayed sulcation and/or too-numerous cortical infoldings (abnormal morphology). Fifteen fetuses had cerebellar and/or brain stem abnormalities. Fetal MR imaging findings suggested a genetic syndrome in 5 fetuses and an acquired etiology or genetic/metabolic disorder in 2 fetuses. Findings were confirmed in 8 cases with postnatal MR imaging, except for delayed sulcation and small vermis, and in 4 cases with autopsy, except for periventricular nodular heterotopia and abnormalities in areas not examined by autopsy. Neurodevelopmental outcome was good in 7 and poor in 9 children. Abnormal sulcal morphology and/or infratentorial abnormalities were present in those with poor outcome and absent in those with good outcome. ACC is infrequently isolated in fetuses. Abnormal sulcation is common and suggests more diffuse white matter dysgenesis in these fetuses.
Purpose: Corpus callosum (CC) is the largest forebrain commissure. This review focuses on the significance of CC for seizure disorders, the role of CC in seizure spread and the surgical disruption of callosal fibers (callosotomy) for treatment of patients with drug-resistant epilepsy. Methods: Personal experience/extensive literature review. Results: Structural CC pathologies comprise developmental abnormalities, callosal involvement in identified disorders, transient imaging findings and microstructural changes. Epilepsies are reported in up to two thirds of patients with complete or partial CC agenesis (AgCC). However, AgCC per se is not indicative for seizure disorders. Moreover, additional malformations of cortical development (MCD) are causal. Microstructural CC abnormalities are detected by advanced imaging techniques, are part of diffuse white matter disturbances and are related to cognitive deficits. The etiological significance remains unexplained. However, they are also found in non-epileptic benign and transient disorders. In drug-resistant epilepsies with violent drops to the floor ("drop seizures") callosotomy may be beneficial in seizure reduction. Since the EEG after callosotomy exhibits a single seizure focus in up to 50% of patients, consecutive resective surgical methods might be successful. Conclusion: CC is part of cerebral white matter and anomalies cannot act per se as seizure onset zone. Imaging techniques demonstrate additional lesions in patients with epilepsies. CC is the major pathway for seizure generalization. Therefore, callosotomy is used to prevent generalized drop seizures.
Corpus callosum agenesis (CCA) is generally diagnosed in utero. Outcome appears to be better if the malformation is isolated. The aim of this study, which is the first one with a long (10 years) and standardized follow up, was to report cognitive abilities of children with isolated CCA diagnosed prenatally. We prospectively evaluated 17 children. Clinical examinations, neuropsychological tests were performed each year. School achievement and personal and familial data were collected. Twelve children completed the entire follow up. One child was finally considered to have associated CCA, because signs of fetal alcohol syndrome had become obvious. Of the 11 other children, three (27%) had borderline intelligence whereas the intelligence levels of eight (73%) were in the normal range, although half of these children experienced some difficulties in scholastic achievement. Neither epilepsy nor intellectual deficiency was noted and intellectual quotient scores correlated strongly with the mother's education level. Although prenatal diagnosis of isolated CCA is reliable, false postnatal diagnoses remain possible (10-20%) even with complete prenatal screening. Outcome is mostly favorable because intelligence is within the normal range for nearly 3/4 of the children. However, they frequently have mild learning difficulties.
Data regarding the epidemiology of callosal anomalies are contradictory. We performed a population-based retrospective survey to study the birth prevalence and clinical features of agenesis/hypoplasia of the corpus callosum and accompanying central nervous system and somatic abnormalities in southeastern Hungary between July 1, 1992 and June 30, 2006. Among 185,486 live births, 38 patients (26 boys and 12 girls) manifested agenesis/hypoplasia of the corpus callosum, corresponding to a prevalence of 2.05 per 10,000 live births (95% confidence interval, 1.4-2.7). Callosal anomalies were isolated in 18 patients, and were associated with other central nervous system malformations in five children. Both central nervous system and noncentral nervous system abnormalities were evident in seven patients, whereas callosal dysgenesis was accompanied only by somatic anomalies in eight children. Five of 18 patients with isolated agenesis/hypoplasia of the corpus callosum remained asymptomatic. Developmental delay, intellectual disability, or epilepsy occurred in all patients, except one, when callosal anomalies were combined with other brain or somatic abnormalities. Five patients with multiplex malformations died. Callosal anomalies form a clinically significant and relatively frequent group of central nervous system malformations.