DOI: 10.1148/rg.253045103
RadioGraphics 2005;25:647-657
© RSNA, 2005
Fetal Schizencephaly: Pre- and Postnatal Imaging with a Review of the Clinical Manifestations1
Karen Y. Oh, MD,
Anne M. Kennedy, MD,
Antonio E. Frias, Jr, MD and
Janice L. B. Byrne, MD
1 From the Departments of Radiology (K.Y.O., A.M.K.) and Obstetrics and Gynecology (A.E.F., J.L.B.B.), University of Utah, 30 N 1900 E, SOM1A71, Salt Lake City, UT 84132. Presented as an education exhibit at the 2003 RSNA Scientific Assembly. Received May 13, 2004; revision requested June 8; revision received and accepted July 12. All authors have no financial relationships to disclose.
Address correspondence to K.Y.O. (e-mail: karen.oh{at}hsc.utah.edu).
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Abstract
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Schizencephaly is a rare malformation of the central nervous system. Prenatal ultrasound (US) allows diagnosis of schizencephaly, although prenatal magnetic resonance (MR) imaging is even more specific in detection of gray matter lining the defect, communication with the ventricle, and other associated structural abnormalities. Six cases of schizencephaly were evaluated at one institution; prenatal US was performed in all cases, and fetal MR imaging was performed in three cases. As with many malformations, more severe cases of schizencephaly often manifest in utero. All of the cases studied were of the open-lip variety; three cases were bilateral, and three were unilateral. The cleft was not appreciated at initial US in only one case, which consisted of a small unilateral defect, with the diagnosis made at subsequent MR imaging. A survey of the clinical literature on schizencephaly shows that the severity of the motor and mental impairments is directly related to the extent of the anatomic defect. The differential diagnosis for a cerebrospinal fluid–containing abnormality of the fetal brain includes both developmental and destructive lesions. Prenatal detection of schizencephaly can assist in management of the pregnancy.
© RSNA, 2005
Abbreviations: CNS = central nervous system, CSF = cerebrospinal fluid, CSP = cavum septi pellucidi, SSFSE = single-shot fast spin-echo
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Introduction
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Schizencephaly is a rare central nervous system (CNS) malformation and is one of the least common causes of a cerebrospinal fluid (CSF)–containing abnormality in the fetus. The diagnosis has previously been made after birth when the child presents with developmental delay or seizures. Scattered reports of prenatal diagnosis exist, although with more widespread use of prenatal ultrasound (US) screening, earlier and more specific diagnoses can consistently be made. The prenatal diagnosis of schizencephaly would be helpful for patient counseling and pregnancy management. In this article, our objective is to demonstrate the prenatal US and fetal magnetic resonance (MR) imaging findings of schizencephaly, review the differential diagnosis for CSF-containing intracranial defects, and review the clinical outcomes.
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Imaging Evaluation
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Six cases of prenatally diagnosed schizencephaly were reviewed, with correlative fetal MR imaging performed in three cases. MR imaging was performed with patient consent by using a 1.5-T LX NVI/CVI unit (GE Medical Systems, Milwaukee, Wis). Single-shot fast spin-echo (SSFSE) and fast multiphase spoiled gradient-echo (FMPSPGR) sequences were used without gadolinium contrast material or maternal sedation. US was performed by using Sequoia or Aspen units (Acuson, Mountain View, Calif) with a 4- or 6-MHz transducer.
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Results
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Clinical information was gathered with the permission of the internal review board. Maternal age ranged from 17 to 34 years, with an average age of 23.3 years. Fetal sex was predominantly male (Table 1).
Radiologic findings are summarized in Table 2. The fetal age reported in weeks represents the gestational age estimated by means of the last menstrual period in all cases but patients 2 and 5, in whom gestational age was dated by means of prior sonography. Fetal size was concordant with the dates of the last menstrual period or prior US findings in all cases.
Patient 1 was imaged at 32.3 weeks for a diagnosis of possible holoprosencephaly. Bilateral wedge-shaped defects were identified (Fig 1a). The thalami were not fused (excluding alobar holoprosencephaly), and echogenic cortex lined the clefts. The cavum septi pellucidi (CSP) was absent. Doppler imaging demonstrated a normal circle of Willis, therefore excluding hydranencephaly (Fig 1b).
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Figure 1a. Patient 1. (a) Axial US image shows bilateral open-lip wedge-shaped defects in the parietotemporal regions. The thalami are not fused. (b) Axial US image shows flow in the vessels of the circle of Willis. This finding proves that the defects are not due to vascular occlusion.
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Figure 1b. Patient 1. (a) Axial US image shows bilateral open-lip wedge-shaped defects in the parietotemporal regions. The thalami are not fused. (b) Axial US image shows flow in the vessels of the circle of Willis. This finding proves that the defects are not due to vascular occlusion.
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Patient 2 was referred from an outside obstetrician for "abnormal ultrasound" at 38.1 weeks. The fetus had bilateral large defects involving the majority of the cerebral hemispheres, consistent with schizencephaly (Fig 2).
Patient 3 was imaged at 36.4 weeks for follow-up of hydrocephalus. Sonography showed a small unilateral schizencephalic cleft on the right, which extended to the inner table of the skull (Fig 3). The thalami and brainstem were normal. There was associated hydrocephalus, which involved the right ventricular system more severely than the left. The head circumference/abdominal circumference (HC/AC) ratio was abnormal in this patient secondary to the increasing hydrocephalus.
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Figure 3. Patient 3. Coronal US image shows a focal small schizencephalic defect (arrow). Note the absent CSP and the ventriculomegaly; the defect extends from the ventricle to the pial surface. This appearance can be difficult to differentiate from porencephaly. However, accurate diagnosis is important because some causes of porencephaly, such as intracranial hemorrhage, can be associated with a significant risk of recurrence.
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Patient 4 was being seen for "anomalies" at 34 weeks. US demonstrated bilateral moderate defects with an absent CSP (Fig 4a). A posterior fossa fluid collection was also identified, and subsequent fetal MR imaging allowed confirmation of the schizencephaly and demonstrated a Dandy-Walker variant (Fig 4b–4d). In this case, postnatal computed tomography (CT) was also performed (Fig 4e).
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Figure 4a. Patient 4. (a) Axial US image shows bilateral large schizencephalic defects and absence of the CSP. A Dandy-Walker variant was also suspected. (b) Coronal SSFSE T2-weighted fetal MR image obtained subsequently shows the large defects. Note that the thalami (T) are not fused; this finding allows differentiation of this malformation from alobar holoprosencephaly. A roofing membrane is partially visualized (arrows). (c) Axial SSFSE T2-weighted fetal MR image shows a Dandy-Walker cyst (arrows) and the schizencephalic defects. T = thalami. (d) Sagittal SSFSE T2-weighted fetal MR image shows the schizencephalic defects and the Dandy-Walker malformation. (e) Postnatal axial computed tomographic (CT) image obtained through the brain shows that the large bilateral clefts communicate with the ventricles.
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Figure 4b. Patient 4. (a) Axial US image shows bilateral large schizencephalic defects and absence of the CSP. A Dandy-Walker variant was also suspected. (b) Coronal SSFSE T2-weighted fetal MR image obtained subsequently shows the large defects. Note that the thalami (T) are not fused; this finding allows differentiation of this malformation from alobar holoprosencephaly. A roofing membrane is partially visualized (arrows). (c) Axial SSFSE T2-weighted fetal MR image shows a Dandy-Walker cyst (arrows) and the schizencephalic defects. T = thalami. (d) Sagittal SSFSE T2-weighted fetal MR image shows the schizencephalic defects and the Dandy-Walker malformation. (e) Postnatal axial computed tomographic (CT) image obtained through the brain shows that the large bilateral clefts communicate with the ventricles.
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Figure 4c. Patient 4. (a) Axial US image shows bilateral large schizencephalic defects and absence of the CSP. A Dandy-Walker variant was also suspected. (b) Coronal SSFSE T2-weighted fetal MR image obtained subsequently shows the large defects. Note that the thalami (T) are not fused; this finding allows differentiation of this malformation from alobar holoprosencephaly. A roofing membrane is partially visualized (arrows). (c) Axial SSFSE T2-weighted fetal MR image shows a Dandy-Walker cyst (arrows) and the schizencephalic defects. T = thalami. (d) Sagittal SSFSE T2-weighted fetal MR image shows the schizencephalic defects and the Dandy-Walker malformation. (e) Postnatal axial computed tomographic (CT) image obtained through the brain shows that the large bilateral clefts communicate with the ventricles.
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Figure 4d. Patient 4. (a) Axial US image shows bilateral large schizencephalic defects and absence of the CSP. A Dandy-Walker variant was also suspected. (b) Coronal SSFSE T2-weighted fetal MR image obtained subsequently shows the large defects. Note that the thalami (T) are not fused; this finding allows differentiation of this malformation from alobar holoprosencephaly. A roofing membrane is partially visualized (arrows). (c) Axial SSFSE T2-weighted fetal MR image shows a Dandy-Walker cyst (arrows) and the schizencephalic defects. T = thalami. (d) Sagittal SSFSE T2-weighted fetal MR image shows the schizencephalic defects and the Dandy-Walker malformation. (e) Postnatal axial computed tomographic (CT) image obtained through the brain shows that the large bilateral clefts communicate with the ventricles.
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Figure 4e. Patient 4. (a) Axial US image shows bilateral large schizencephalic defects and absence of the CSP. A Dandy-Walker variant was also suspected. (b) Coronal SSFSE T2-weighted fetal MR image obtained subsequently shows the large defects. Note that the thalami (T) are not fused; this finding allows differentiation of this malformation from alobar holoprosencephaly. A roofing membrane is partially visualized (arrows). (c) Axial SSFSE T2-weighted fetal MR image shows a Dandy-Walker cyst (arrows) and the schizencephalic defects. T = thalami. (d) Sagittal SSFSE T2-weighted fetal MR image shows the schizencephalic defects and the Dandy-Walker malformation. (e) Postnatal axial computed tomographic (CT) image obtained through the brain shows that the large bilateral clefts communicate with the ventricles.
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Patient 5 was imaged at 32.1 weeks for follow-up of a known "cranial abnormality," and an absent CSP was shown. The schizencephaly defect was not clearly identified (Fig 5). This patient subsequently underwent fetal MR imaging, which demonstrated a cortical defect.
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Figure 5a. Patient 5. (a) Axial US image obtained through the brain shows absence of the CSP (arrow). A small schizencephalic defect was not identified at initial prenatal US. (b) Comparison US image of an infant who was normal at birth shows a slightly prominent CSP.
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Figure 5b. Patient 5. (a) Axial US image obtained through the brain shows absence of the CSP (arrow). A small schizencephalic defect was not identified at initial prenatal US. (b) Comparison US image of an infant who was normal at birth shows a slightly prominent CSP.
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Patient 6 was imaged at 34.3 weeks with no prior prenatal care. The lateral ventricles were mildly dilated with a wedge-shaped schizencephaly defect on the right (Fig 6). The CSP was absent, as well as the corpus callosum.
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Figure 6a. Patient 6. (a) Axial US image shows mild ventriculomegaly (cursors) with a wedge-shaped schizencephalic defect (arrows). The CSP is absent. (b) Postnatal CT image shows the gray matter–lined defect extending from the occipital horn of the lateral ventricle to the pial surface.
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Figure 6b. Patient 6. (a) Axial US image shows mild ventriculomegaly (cursors) with a wedge-shaped schizencephalic defect (arrows). The CSP is absent. (b) Postnatal CT image shows the gray matter–lined defect extending from the occipital horn of the lateral ventricle to the pial surface.
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Discussion
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The modern definition of schizencephaly was initially described by Yakovlev and Wadsworth (1,2), although descriptions of schizencephaly were reported first in the late 19th century (3). Closed-lip schizencephaly is characterized by gray matter–lined lips that are in contact with each other (type 1). Open-lip schizencephaly has separated lips and a cleft of CSF, extending to the underlying ventricle (type 2) (Fig 7). In many CNS anomalies, there are associated facial malformations; however, we found normal profiles and facial features in this series of schizencephaly cases (Fig 8). The characteristic imaging features of schizencephaly in the postnatal population are listed in Table 3 (Fig 9) (4).
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Figure 7a. Open-lip schizencephaly. (a) Axial SSFSE T2-weighted fetal MR image of patient 2 shows bilateral giant schizencephalic defects lined with gray matter. The thalami are not fused. (b) Axial SSFSE T2-weighted postnatal MR image shows the gray matter–lined defects. Note the presence of the falx, which makes the diagnosis of holoprosencephaly unlikely.
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Figure 7b. Open-lip schizencephaly. (a) Axial SSFSE T2-weighted fetal MR image of patient 2 shows bilateral giant schizencephalic defects lined with gray matter. The thalami are not fused. (b) Axial SSFSE T2-weighted postnatal MR image shows the gray matter–lined defects. Note the presence of the falx, which makes the diagnosis of holoprosencephaly unlikely.
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Figure 8. Normal facial characteristics. Sagittal SSFSE T2-weighted MR image of patient 2 shows a normal fetal profile, despite the large defects seen in this patient (Figs 2, 7). In the authors’ experience, schizencephaly is most often associated with normal facial characteristics.
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Figure 9a. Characteristic imaging features. (a) Axial SSFSE T2-weighted fetal MR image shows a focal schizencephalic cleft extending from the pial surface to the ventricle (arrow). The cleft is lined with gray matter, which is seen as a low-signal-intensity line covering the edge of the remaining brain parenchyma (arrowheads). This finding allows differentiation of the defect from porencephaly. In addition, the CSP is absent (*). (b) Coronal SSFSE T2-weighted fetal MR image shows that the anterior horn of the lateral ventricle is tented, thus pointing to the defect.
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Figure 9b. Characteristic imaging features. (a) Axial SSFSE T2-weighted fetal MR image shows a focal schizencephalic cleft extending from the pial surface to the ventricle (arrow). The cleft is lined with gray matter, which is seen as a low-signal-intensity line covering the edge of the remaining brain parenchyma (arrowheads). This finding allows differentiation of the defect from porencephaly. In addition, the CSP is absent (*). (b) Coronal SSFSE T2-weighted fetal MR image shows that the anterior horn of the lateral ventricle is tented, thus pointing to the defect.
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The etiology is unclear, although a primary malformation secondary to a neuronal migrational anomaly is considered most likely. Familial cases of schizencephaly have been reported, suggesting a possible genetic origin within a group of neuronal migration disorders (5). Brunelli et al (6) have reported heterozygous mutations of the EMX2 gene associated with schizencephaly (7). However, early prenatal injury, such as that associated with drug abuse or abdominal trauma, has also been reported to be associated with schizencephaly, possibly from a vascular insult (8). Iannetti et al (9) reported cases of clefts resulting from cytomegalovirus infection. Therefore, the appearance of schizencephaly is likely secondary to multiple factors, leading to a final common manifestation of abnormal neuronal migration.
Clinical manifestations of schizencephaly most often include varying degrees of developmental delay, motor impairment, and seizures (10,11) (Table 4). Granata et al (7) concluded that the severity of the motor and mental deficiencies correlated with the extent of the anatomic defect. However, the presence or severity of epilepsy did not correlate with the extent of the defect.
Open-lip clefts usually result in the most significant impairment, while unilateral clefts have a less severe clinical phenotype. If there is a small, unilateral closed-lip cleft without involvement of the motor cortex, the patient is usually normal except for seizures (Fig 10) (12). Aniskiewicz et al (13) stressed the need for comprehensive neuro-psychologic and speech/language studies because the level of intellectual function is thought to be related to the amount of brain tissue involved. Neurobehavioral abilities are thought to reflect the location of the malformation (13). Recently, Liang et al (14) reported the imaging findings and correlated these with clinical features, concluding that children with schizencephaly have variable neurological impairment and that neuroimaging is helpful in predicting neurodevelopmental outcomes. For example, children with bilateral schizencephaly and intractable seizures had the worst outcome (12,14). Clearly, there is a wide range of clinical phenotypes associated with schizencephaly, depending on the size of the defect, unilateral versus bilateral defect, and open- versus closed-lip defect (Table 5). Therefore, prenatal identification and characterization of the defect can be beneficial in counseling parents what to expect with the development of their child.
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Figure 10. Small schizencephalic defect. Axial SSFSE T2-weighted MR image of patient 5 shows a small, unilateral open-lip cleft extending to the underlying occipital horn. This defect was not identified at initial prenatal US (Fig 5a).
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Barkovich and Norman (15) initially described MR imaging findings of schizencephaly in adults, finding that MR imaging is more sensitive than CT in detecting the clefts as well as associated abnormalities such as pachygyria, polymicrogyria, and heterotopic gray matter. Barkovich and Norman (15) also suggested that there may be a common pathogenetic origin for polymicrogyria and schizencephaly, both being secondary to migrational anomalies caused by insults to migrating neuroblasts in the third to fifth gestational months. Hayashi et al (4) found that polymicrogyria was identified both adjacent to and remote to the cleft in 66% of the cases they reviewed. Barkovich et al (16) and Kuban et al (17) both also note the association of schizencephaly with septo-optic dysplasia (often suggested prenatally by the absent CSP).
These reports have evaluated the pediatric or adult populations, although there have been sporadic reports of antenatal diagnosis of schizencephaly with US, a few with the aid of MR imaging (18–20). Denis et al (21) reviewed three cases of antenatally diagnosed open-lip schizencephaly, one of the only series stressing prenatal diagnosis. This group used HASTE (half-Fourier acquisition single-shot turbo spin-echo) imaging, with flunitrazepam administered to the mother for fetal sedation. Our fetal MR imaging protocol uses single-shot fast spin-echo (SSFSE) imaging without fetal sedation, showing that adequate imaging can be achieved without medication. In the series of Denis et al (21), the diagnosis of schizencephaly led to termination of pregnancy in all cases after the clinical aspects of the disease were discussed with the parents. Clearly, prenatal diagnosis of schizencephaly can aid in the management of the pregnancy. Even if pregnancy termination is not an option, the parents will at least be able to prepare themselves and their families for the inevitable clinical consequences of the defect.
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Conclusions
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Prenatal imaging allows detection and characterization of open-lip schizencephaly. To date, we have not diagnosed the closed-lip type (type 1) and are unaware of any reported cases. Prenatal MR imaging delineates gray matter lining the defect and the communication with the ventricle. Additional abnormalities such as polymicrogyria may also be demonstrated. When a patient with a CSF-containing defect is initially evaluated, a differential diagnosis should be considered. This includes developmental and destructive lesions of the fetal brain (Table 6) (Figs 11, 12). MR imaging can aid in distinguishing schizencephaly from the list of differential diagnoses better than US and has the additional benefit of delineating other associated brain anomalies.
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Figure 11a. Destructive lesions included in the differential diagnosis of schizencephaly. (a) Coronal SSFSE T2-weighted fetal MR image shows porencephaly. The hyperintense fluid collection is contained within the brain parenchyma, and a tiny rim of residual parenchymal tissue is present (arrow). Note that the collection is not lined with gray matter, unlike in schizencephaly. (b) Axial SSFSE T2-weighted MR image of a fetus with hydranencephaly shows large CSF collections and no significant residual parenchymal tissue. The falx is present, which allows differentiation of this condition from alobar holoprosencephaly.
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Figure 11b. Destructive lesions included in the differential diagnosis of schizencephaly. (a) Coronal SSFSE T2-weighted fetal MR image shows porencephaly. The hyperintense fluid collection is contained within the brain parenchyma, and a tiny rim of residual parenchymal tissue is present (arrow). Note that the collection is not lined with gray matter, unlike in schizencephaly. (b) Axial SSFSE T2-weighted MR image of a fetus with hydranencephaly shows large CSF collections and no significant residual parenchymal tissue. The falx is present, which allows differentiation of this condition from alobar holoprosencephaly.
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Figure 12a. Developmental lesions included in the differential diagnosis of schizencephaly. (a) Axial SSFSE T2-weighted fetal MR image shows an arachnoid cyst near the vertex. Unlike a schizencephalic defect, this lesion is in the extra-axial space. (b) Axial US image of another fetus shows the fused thalami (T) seen in holoprosencephaly, a mimic of schizencephaly. There appear to be bilateral wedge-shaped defects on this image; however, on images obtained in more superior planes, it was apparent that the "defects" communicated across the midline. (c) Coronal SSFSE T2-weighted fetal MR image shows a monoventricle, which confirms the diagnosis of holoprosencephaly. The black line represents the plane of the US image (b), which included part of the monoventricle bilaterally and gave the illusion of clefts. (d) Coronal SSFSE T2-weighted MR image of another fetus shows a large fluid collection in the midline. Although the collection is lined with gray matter (arrows), it is not continuous with the ventricles and is actually extra-axial. This patient has agenesis of the corpus callosum with a large interhemispheric cyst.
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Figure 12b. Developmental lesions included in the differential diagnosis of schizencephaly. (a) Axial SSFSE T2-weighted fetal MR image shows an arachnoid cyst near the vertex. Unlike a schizencephalic defect, this lesion is in the extra-axial space. (b) Axial US image of another fetus shows the fused thalami (T) seen in holoprosencephaly, a mimic of schizencephaly. There appear to be bilateral wedge-shaped defects on this image; however, on images obtained in more superior planes, it was apparent that the "defects" communicated across the midline. (c) Coronal SSFSE T2-weighted fetal MR image shows a monoventricle, which confirms the diagnosis of holoprosencephaly. The black line represents the plane of the US image (b), which included part of the monoventricle bilaterally and gave the illusion of clefts. (d) Coronal SSFSE T2-weighted MR image of another fetus shows a large fluid collection in the midline. Although the collection is lined with gray matter (arrows), it is not continuous with the ventricles and is actually extra-axial. This patient has agenesis of the corpus callosum with a large interhemispheric cyst.
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Figure 12c. Developmental lesions included in the differential diagnosis of schizencephaly. (a) Axial SSFSE T2-weighted fetal MR image shows an arachnoid cyst near the vertex. Unlike a schizencephalic defect, this lesion is in the extra-axial space. (b) Axial US image of another fetus shows the fused thalami (T) seen in holoprosencephaly, a mimic of schizencephaly. There appear to be bilateral wedge-shaped defects on this image; however, on images obtained in more superior planes, it was apparent that the "defects" communicated across the midline. (c) Coronal SSFSE T2-weighted fetal MR image shows a monoventricle, which confirms the diagnosis of holoprosencephaly. The black line represents the plane of the US image (b), which included part of the monoventricle bilaterally and gave the illusion of clefts. (d) Coronal SSFSE T2-weighted MR image of another fetus shows a large fluid collection in the midline. Although the collection is lined with gray matter (arrows), it is not continuous with the ventricles and is actually extra-axial. This patient has agenesis of the corpus callosum with a large interhemispheric cyst.
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Figure 12d. Developmental lesions included in the differential diagnosis of schizencephaly. (a) Axial SSFSE T2-weighted fetal MR image shows an arachnoid cyst near the vertex. Unlike a schizencephalic defect, this lesion is in the extra-axial space. (b) Axial US image of another fetus shows the fused thalami (T) seen in holoprosencephaly, a mimic of schizencephaly. There appear to be bilateral wedge-shaped defects on this image; however, on images obtained in more superior planes, it was apparent that the "defects" communicated across the midline. (c) Coronal SSFSE T2-weighted fetal MR image shows a monoventricle, which confirms the diagnosis of holoprosencephaly. The black line represents the plane of the US image (b), which included part of the monoventricle bilaterally and gave the illusion of clefts. (d) Coronal SSFSE T2-weighted MR image of another fetus shows a large fluid collection in the midline. Although the collection is lined with gray matter (arrows), it is not continuous with the ventricles and is actually extra-axial. This patient has agenesis of the corpus callosum with a large interhemispheric cyst.
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The severity of the motor and mental impairment is related directly to the extent of the anatomic abnormality. Seizure activity and severity are also related to the type and extent of the clefts. Given that no postnatal therapeutic options exist, accurate prenatal detection can assist in management of the pregnancy and in counseling of the parents about the clinical manifestations of schizencephaly.
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References
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- Yakovlev PI, Wadsworth RC. Schizencephalies: a study of the congenital clefts in the cerebral mantle. I. Clefts with fused lips. J Neuropathol Exp Neurol
1946; 5:116–130.
- Yakovlev PI, Wadsworth RC. Schizencephalies: a study of the congenital clefts in the cerebral mantle. II. Clefts with hydrocephalus and lips separated. J Neuropathol Exp Neurol
1946; 5:169–206.
- Wilmarth WA. Presentation to the Philadelphia Neurological Society. J Nerv Ment Dis
1887;395–407.
- Hayashi N, Tsutsumi Y, Barkovich AJ. Morphological features and associated anomalies of schizencephaly in the clinical population: detailed analysis of MR images. Neuroradiology
2002; 44:418–427.[CrossRef][Medline]
- Hilburger AC, Willis JK, Bouldin E, Henderson-Tilton A. Familial schizencephaly. Brain Dev
1993; 15:234–236.[CrossRef][Medline]
- Brunelli S, Faiella A, Capra V, et al. Germline mutations in the homeobox gene EMX2 in patients with severe schizencephaly. Nat Genet
1996; 12:94–96.[CrossRef][Medline]
- Granata T, Farina L, Faiella A, et al. Familial schizencephaly associated with EMX2 mutation. Neurology
1997; 48:1403–1406.[Abstract]
- Montenegro MA, Guerreiro MM, Lopes-Cendes I, et al. Interrelationship of genetics and prenatal injury in the genesis of malformations of cortical development. Arch Neurol
2002; 59:1147–1153.[Abstract/Free Full Text]
- Iannetti P, Nigro G, Spalice A, Faiella A, Boncinelli E. Cytomegalovirus infection and schizencephaly: case reports. Ann Neurol
1998; 43:123–127.[CrossRef][Medline]
- Guerrini R, Carrozzo R. Epilepsy and genetic malformations of the cerebral cortex. Am J Med Genet
2001; 106:160–173.[CrossRef][Medline]
- Komarniski CA, Cyr DR, Mack LA, Weinberger E. Prenatal diagnosis of schizencephaly. J Ultrasound Med
1990; 9:305–307.[Medline]
- Barkovich AJ, Kjos BO. Schizencephaly: correlation of clinical findings with MR characteristics. AJNR Am J Neuroradiol
1992; 13:85–94.[Abstract]
- Aniskiewicz AS, Frumkin NL, Brady DE, et al. Magnetic resonance imaging and neurobehavioral correlates in schizencephaly. Arch Neurol
1990; 47:911–916.[Abstract]
- Liang JS, Lee WT, Peng SS, Yu TW, Shen YZ. Schizencephaly: correlation between clinical and neuroimaging features. Acta Paediatr Taiwan
2002; 43:208–213.[Medline]
- Barkovich AJ, Norman D. MR imaging of schizencephaly. AJR Am J Roentgenol
1988; 150:1391–1396.[Abstract/Free Full Text]
- Barkovich AJ, Fram EK, Norman D. Septo-optic dysplasia: MR imaging. Radiology
1989; 171: 189–192.[Abstract/Free Full Text]
- Kuban KC, Teele RL, Wallman J. Septo-optic-dysplasia-schizencephaly: radiographic and clinical features. Pediatr Radiol
1989; 19:145–150.[CrossRef][Medline]
- Klingensmith WC, Cioffi-Ragan DT. Schizencephaly: diagnosis and progression in utero. Radiology
1986; 159:617–618.[Abstract/Free Full Text]
- Lituania M, Passamonti U, Cordone MS, Magnano GM, Toma P. Schizencephaly: prenatal diagnosis by computed sonography and magnetic resonance imaging. Prenat Diagn
1989; 9:649–655.[Medline]
- McGahan JP, Ellis W, Lindfors KK, Lee BC, Arnold JP. Congenital cerebrospinal fluid-containing intracranial abnormalities: a sonographic classification. J Clin Ultrasound
1988; 16:531–544.[Medline]
- Denis D, Maugey-Laulom B, Carles D, Pedespan J, Brun M, Chateil J. Prenatal diagnosis of schizencephaly by fetal magnetic resonance imaging. Fetal Diagn Ther
2001; 16:354–359.[CrossRef][Medline]
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Abstract
Introduction
